How to Burglar-Proof Your Home 0882292455, 0882295055, 9780882295053

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HOW 10 BURGLAR-PROOF

ROBERT L. ROBINSON

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how to BURGLARPROOF your home

Digitized by the Internet Archive in 2023 with funding from Kahle/Austin Foundation

https://archive.org/details/nowtoburglarproo0000robi

Robert L. Robinson

how to BURGLARPROOF your home Nelson-Hall

Chicago

Library of Congress Cataloging in Publication Data

Robinson, Robert L. How to burglar-proof your home.

Includes index. 1. Burglary protection measures. I. Title. TH9745.D85R6 ISBN 0-88229-245-5 ISBN 0-88229-505-5

2. Dwellings—Security

643

76-54352

(hard cover) (paperback)

Copyright © 1977 by Robert L. Robinson

All rights reserved. No part of this book may be reproduced in any form without permission in writing from the publisher, except by a reviewer who wishes to quote brief passages in connection with a review written for broadcast or for inclusion in a magazine or newspaper. For information address NelsonHall Inc., 325 West Jackson Blvd., Chicago, Illinois 60606. Manufactured in the United States of America.

To the officers of Burglary Divisions everywhere—in the hope that this may help to lessen their burden.

i

PRO PERTY ry OF PUBLIC LIBRARY ny

Contents

Illustrations/ix Objectives of Deterrent Measures /1

Entry Doors without Glass /9 Safety Chains. Locks. Secure Installation of Lock Strikes.

Entry Doors with Glass/31 Special Glass. Locking Requirements for Doors with Glass. Considerations Regarding Double Cylinder Locks.

Other Considerations Regarding Doors / 43 Types of Doors. Other Factors Affecting Door Security. Wire Glass and Burglary Resistive Glass. Secondary Entrances. Interior Doors. Condition of Locks.

Windows/

85

Locations of Windows.

Window Locks and Locking Meth-

ods. Storm Windows and Screens, Bars and Grilles. Secur-

ing Window Frames. Metal Window Frames. Special Glass. Balancing Effectiveness of Deterrent Measures. Basement Windows. Window Air Conditioners and Fans.

Other Openings / 101 Attic Ventilators. Exhaust Fans. Roof Hatches. Central Air Conditioners. Air Intake Fans. Foundation Vents and Craw! Entries. Utility Entrances. Hasps and Padlocks.

Structural Integrity /115 Roofs. Outside Walls. Interior Walls and Ceilings. The Theory of Saw Resistance. Keeping Protective Measures Consistent. Sanitary Doors. Individual Service Elevators or Dumb Waiters. Laundry Chutes. Letter Box Slots. Delivery or Catering Doors. Excessive Gaps under Doors. Garages.

Porches. Attached Sheds. Attached Outside Stairs.

Safes, Containers,

and Alarms / 137

Money Chests. Record Safes. Insulated File Cabinets. Noninsulated Metal File Cabinets. Lock Boxes. Safe-Deposit Boxes. Protective Closets, Rooms, and Vaults. Summary Intrusion Alarm Systems.

Precautions

for Unattended

Homes / 157

Daytime Absences. Evening Absences. Overnight or Weekend Absences. Vacations or Prolonged Absences.

10.

Intrinsic and Nonphysical Factors / 165 Lighting. Suspicious Activities. Business-Associated Risks. Effectiveness of Deterrents. Quality of Police Protection. What to Do When a Burglary Occurs.

Index /175

Illustrations

The Mortise Deadlatch/ 14 The Rim Deadlatch / 17 The Cylindrical Deadlatch/19 A Mortise Deadbolt / 22 A Rim Deadbolt / 24 A Jimmy-Proof Rim Lock / 25 A Tubular Deadbolt / 27 ae Pongal ae ah olga A Surface Bolt / 29 SS A Mortise Bolt / 29 Wire Glass in Modern Construction / 32 A Double Cylinder Mortise Deadbolt /35 A Double Cylinder Rim Deadbolt / 36 A Double Cylinder Jimmy-Proof Rim Lock / 37 Making Screws Tamper-Resistant / 38 A Dual Cylinder Tubular Deadbolt / 39 Panel Doors/45 A Hollow-Core Door / 47

Full Mortise Butt, Loose Pin/ 52 Nonremovable Pin Feature / 53 Fast Riveted Pin (FRP) Construction / 55 Full Mortise Butt with Security Stud / 56 Half Surface Butt / 58 Burglary Resistive Glass/61 A Mortise Springlatch / 67 A Rim Springlatch / 68 A Cylindrical Springlatch / 70 Comparison of New and Worn Pin Tumbler Cylinders / 74

New and Worn Disc Tumblers / 76 Testing the Springlatch/ 78 Testing the Deadlatch/81 Testing the Deadbolt / 82 Common Sash Lock / 86 Key-Operated Sash Locks / 87 Securing a Window

Frame / 92

Hook Lock Devices for Metal Window Frames / 94 A Hinge Hasp/ 110

A Safety Hasp/111 Optimum Pilot Hole Size for Wood Screws / 113 Increasing the Burglary Resistance of Roofs / 117 Structural Protection for Outside Frame Walls/120

Chicken Wire or Mesh Wire to Augment Protection Furnished by Interior Walls or Ceilings/123

Improperly Locked Attached Garages Can Conceal Burglars / 132 Shhh! Burglar at Work! / 136 Money Chest / 139 Record Safe /144 Elements of an Intrusion Alarm System/ 152 Landscaping as an Invitation to Burglary / 167

1 Objectives of Deterrent Measures Just as the risk of burglary is twofold—that is, by the amateur burglar or by the professional—so

also are the objectives of deterrent measures. The unskilled burglar can be excluded to a very large extent by the use of appropriate physical and

psychological measures.

For example, the unskilled

burglar cannot cope with quality locks of the proper

type. Deterrents that would prove merely troublesome to the professional burglar often are virtually insurmountable to the amateur. The use of proper locks and hardware

premises

is an

in the physical safeguarding of

important

factor

in excluding

the

unskilled burglar. Even using the proper locks and hardware, it would be quite fallacious to assume the

complete elimination of the amateur burglar, because he may take risks in ignorance that a professional would avoid like the plague. There is, however, an offsetting factor in that the amateur’s risk of appre1

2 / How to Burglar-proof Your Home

hension is considerably greater when he takes risks that would deter a professional. The objectives of measures to deter the professional burglar are slightly different. One objective is to increase the risk of apprehension, thus making the burglary less appealing and proportionately less likely to occur. One method of increasing the risk of apprehension is by increasing the burglar’s exposure time—that is, increasing the length of time he must spend in the actual process of gaining entry and obtaining access to the target objective. Every minute a burglar spends on the premises, whether inside or outside

(especially

outside),

increases

his

risk

of

apprehension by a significant margin. Another way to increase the risk of apprehension is to introduce factors that cause the burglar to become conspicuous by virtue of the acts he must perform in order to gain entry. Such factors as good locks on the doors and windows can force him to break a window, making him audibly conspicuous. Adequate lighting of the premises can cause a burglar to become visually conspicuous merely by his presence at a door or window. These and any other factors that can be brought into play to make a burglar conspicuous will increase his risks and can serve as a valuable deterrent. Even though no deterrents may be adequate to exclude all burglars, at least they should be of such quality as to require him to use tools that will leave obvious evidence of his means of entry. It is extremely important that such evidence be left, not only to assist in his apprehension and conviction, but because many insurance policies are conditional on the finding of some physical evidence that burglary has taken place or that entry has been gained by force. This particular point has a dual significance to the householder; one is the possible recovery of his

Objectives of Deterrent Measures / 3

property, and the other is compensation for it should recovery be impossible. Reasons for taking certain measures of physical protection are reflected in the specific requirements set forth in connection with the Urban Property Protection and Reinsurance Act of 1968,* which makes federally sponsored burglary insurance available in specified high-risk areas, depending on a “critical market unavailability situation.” Initial measures for physical protection required of the householder under this program, while strict, exhibited some ineptitudes, as did subsequent revisions. Some physical measures that could be taken quite simply and would be quite effective were ignored. One effective deterrent is having the premises watched or checked at random intervals. The neighbors may be alerted at times when one is on an extended stay away from home, or when all members of the household are away at work ona regular basis. Frequently this either helps in the apprehension of a burglar or results in the accumulation of sufficient evidence for his conviction, even though he actually may not be apprehended in the act of commission. Either situation frequently results in the preservation or recovery of the owner's property. Police departments in some cities will make premise inspections at random intervals on the request of a resident who is planning to be absent on an extended stay. The professional burglar is much less likely to attack premises that are being checked by the police department, particularly if those checks are carried out at unpredictable intervals. Another valuable aspect of systematic but randomly timed police checks is the fact that the lapse of time *United States Code, Title 12, 1749bbb, part C, 1968, administered under the Department of the Treasury.

4/ How to Burglar-proof Your Home

between the commission of a burglary and the time it is brought to the attention of the police department usually is reduced. A burglary discovered soon after commission is more often solved quickly enough to permit recovery of the property before it can be fenced. Indeed, a short time lapse between commission and discovery may make the difference between a crime that is cleared by arrest and one that remains unsolved. At times, the use of mechanical, electronic, or other devices will cause a burglar to become conspicuous. Just as the use of mechanical aids such as quality locks, bars, and so on, may force the burglar to make himself conspicuous in gaining entry, electronic devices such as burglar alarms and adequate lighting accomplish the same result. The presence of a dog in the home may be even more effective, whenever this is possible or desirable. The author recalls a recent situation in which three persons forced their way into a home, literally right into the jaws of a large and energetic dog. Two immediately became hospital cases, and the third was very happy to fall into the clutches of police who were cruising the neighborhood. The introduction of elements of uncertainty into planning a burglary can play a significant role in the elimination of a particular premise as a target. One technique used to make the burglar unsure of himself is to make it appear that the premises are occupied, whether or not they are. Most burglars are much less likely to attack places that appear to be occupied than those that obviously are not. The simulation of an alarm system or the actual presence of such a system likewise may have a deterrent effect; however, the simulation of an alarm system should be carefully considered with regard to

Objectives of Deterrent Measures / 5

whether the principal risk is from a professional burglar or an amateur. The simulation of an alarm sys-

tem is much more likely to deter the amateur than the professional because such simulations all too often are rather crudely done and the professional may well recognize a simulation. If he does not recognize it as a simulation, the professional may regard it as an indication of the presence of valuables of sufficient worth to go after, regardless of the presence of an alarm system, or perhaps because of it. The simulation of an alarm system should be considered carefully in view of the alternative motivations involved. It should also be borne in mind that the type of alarm that lends itself to simulation usually is a type that can be defeated by a competent professional. There are two philosophies concerning the actual presence of an alarm system. An obvious alarm system may be a deterrent, but an obvious alarm system also is all too likely to be one that can be circumvented rather easily by a skilled burglar. The obvious type may deter the amateur and the less skilled

career burglar, but it is also true that one of the less obvious types may deter neither the amateur nor the professional. Under these conditions, the amateur may be caught in the act while he is searching out valuables, whereas the professional is much less likely to be caught because he usually knows exactly what he is going after, where it is kept, and what he must do to gain access. Such a burglar is likely to have attained his objective and be gone before the

police respond to the alarm and arrive on the scene— all without the burglar having been aware of tripping an alarm. Obviously, a very important factor in the consideration of the presence of an alarm system and the type to be used must be the elapsed response time—that is, the length of time that it will take for

6 / How to Burglar-proof Your Home

law enforcement personnel to arrive on the scene after the alarm is tripped. Obviously, it is better if the alarm occurs during the time of entry, rather than after entry is achieved and the burglar is ready to leave. Automatically timed lights and appliances, such as radios or television sets, may be effective in making premises appear to be occupied, thus reducing the probability of a burglary attempt by either professional or amateur burglars. Timers for this purpose are available at some drugstores and hardware stores and from most electronics suppliers at quite nominal prices. The timer should be simple to use and must be rated at sufficient wattage to carry the load of the appliances to be controlled by the device. Two or more timers may be used to turn various lights or appliances on or off at different times to increase the illusion of occupancy. Any timer used in this way should be of the twenty-four-hour variety to avoid lights and appliances going on or off at inappropriate times. Photocells may be used to control lighting, either separately or in a bypass arrangement. If used in conjunction with a timer, it would be desirable to have the arrangement set up by a qualified electronic technician or electrician. If they are to be used separately, many people have sufficient familiarity with basic electronics and electricity to set up this type of system themselves. Usually all that is required is to plug the device into an outlet, plug the appliance to be controlled into the timer, set the time (much like setting a clock), and set the “time on” and “time off.” A serious and often decisive factor in whether or not a home or residence is a target for a burglary attempt is the fact that potential loot often is displayed rather ostentatiously in locations where it is

Objectives of Deterrent Measures / 7

visible to casual callers who could be burglars pretending to be salesmen, repairmen, servicemen, and the like. Burglars frequently make preliminary calls of this type at residences to evaluate their potential for burglary. The measures listed on subsequent pages are intended to serve as a guide in correcting deficien-

cies where they exist. They are not absolute in the protection they offer. Nothing is. Techniques presented here are flexible and offer several alternatives in coping realistically with various situations. Many of the alternatives suggested can help correct an existing hazard. They should help determine the extent to which modifications are either necessary or realistically desirable. They are intended simply to provide a basis for rational judgment as to the adequacy of existing arrangements or conditions. Should the existing protective capability be in doubt, alternatives are presented; however, the reader is urged to consult an expert. The guidelines and procedures presented here should enable one to know that once the work has been completed, it has been done properly.

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2 Entry Doors without Glass Logically, a discussion of how to upgrade physical deterrents to burglary would begin with an examination of the normal means of entry to a dwelling. For the sake of simplicity and in the interests of an orderly presentation, let us first consider exterior or

entry doors that have no glass. Doors without glass offer some obvious advantages because their resistance to burglary is virtually uniform. They have no glass that can be broken, and there is no visual access to the interior. There

are, however, certain disadvantages. The principal danger in having an entry door without glass is that of inadvertently opening the door to a stranger who may force his way inside. This disadvantage can be offset, to a degree, by the installation and use of door

viewers.

These

are small optical devices

set into a

hole drilled through the door. They enable one to see 9

10 / How to Burglar-proof Your Home

out without the caller's being able to see into the dwelling. Some of these viewers offer as much as a 140-degree field of vision and require only a small hole in the door. In this way, they provide a visual identification of the caller before the door is opened. It should be remembered that women may be able to make the preliminary survey of premises to be burglarized even more easily than men; it seems that people tend to be less suspicious of them. A word of caution

is in order

in regard

to viewers,

however;

someone could conceal himself in the viewer’s “blind zone’ and have a gun or knife menacing a perfectly legitimate caller!

Safety Chains Another valuable safeguard for entry doors (with or without glass) is the safety chain. The chain is mounted on the inside of the door casing and has a slide button attached to the end of the chain. To place the chain in use, the button is fitted into a track that is mounted on the door itself; this arrangement permits the door to be opened a few inches but prevents further opening until the door is closed and the chain disengaged from the track. A device of this type allows one to see the caller, carry on a conversation, and even pass small packages or papers back and forth without having to admit the caller. Such a safety chain should be strongly secured at both ends. The door bracket should be attached sturdily to the door, and the chain should be firmly anchored to a substantial door casing, which itself must be strongly attached to both the door frame and a wall stud. A safety chain is not intended for use as a door lock under any circumstances. It is simply what the

Entry Doors without Glass / 11

term implies—a safety chain—not a locking device. Safety chains can be defeated rather easily, silently, and quickly when the door is unattended. They must never be the sole means of securing an unattended door. Adequate lighting should be provided at all entry doors so visitors can be recognized or appraised before unlocking the door or releasing the safety chain. Illumination should be provided whether or not a door has windows in order for the safety chain to serve its purpose adequately. Locks

Certain types of locks are appropriate for doors without glass. The most convenient lock function appropriate for doors of this type is the deadlatch. It

also provides prompt exit capability in the event of fire.

Deadlatch

Locks

Locks of the deadlatch function differ from the common springlatch in that they always havea small

auxiliary latch or plunger. It protrudes from the edge of the door in addition to the common latch bolt (see Figures 1 through 3). The auxiliary latch (or plunger) never enters the pocket of the strike plate, which is mounted on the door frame; instead, it is depressed into the lock mechanism by the surface of the strike.

Operating

in this manner,

the auxiliary latch con-

trols a deadlocking mechanism inside the lock case to secure the main latch bolt against end pressure. The

operation

of the

deadlocking

mechanism

tested by the very simple method

may

be

of depressing the

auxiliary latch or plunger to the same position or somewhat less than that to which the surface of the

12 / How to Burglar-proof Your Home

strike plate depresses it when the door is closed. Holding the auxiliary latch in that position, a thumb is used to apply a firm end pressure to the latch bolt. If the latch bolt slides into the lock under these conditions, the deadlocking mechanism is not functioning properly, and the lock needs repair or adjustment. Any test of this function should always be made with the lock in the locked condition, as some deadlatches disengage the deadlatching mechanism when the lock is in the unlocked condition. Tests of the deadlocking mechanism should be performed at more or less regular intervals, say about twice a year to about six times a year, but especially before leaving for a prolonged absence. A deadlocking mechanism in good order is always essential on an entry door that is secured by locking the outside knob, if a reasonable degree of protection is to be obtained. Another essential precaution to take with this type of lock is to make sure that the pocket in the strike is deep enough to permit the latch bolt to extend fully from the lock and into the pocket to the maximum depth that full protrusion can attain. If, because of a too shallow or poorly formed strike pocket, the latch bolt does not protrude fully from the lock, it may not protrude far enough for the deadlatching mechanism (behind the latch bolt) to engage the latch bolt effectively. The deadlatch function is available in three common configurations, which will be discussed briefly in the following paragraphs. The Mortise Deadlatch. The mortise deadlatch (Figure 1) is a lock with a rectangular case that is mortised or recessed into the edge of the door in a more or less rectangular pocket. More modern versions of the mortise deadlatch are recognizable by a

Entry Doors without Glass / 13

pin tumbler lock cylinder that screws into a threaded hole in the lock case above the knob. Most modern deadlatches have a lock front exposed on the edge of the door that is eight inches long, but a few versions of it are made in locks having a front about six inches long. Older versions of the mortise deadlatch also had fronts about six inches long, but used a bit type of keying rather than a pin tumbler lock cylinder. The age of a lock is not necessarily a guide to its quality, since many older locks were quite well made and remain extremely effective when they are in good condition and the mechanism is not excessively worn. Inferior imitations of quality locks were profuse then, as now, and locks of that general type should be

examined carefully by an expert to determine extent of their effectiveness.

the

Knobs must return freely and quickly to their normal] “at rest” position; if they do not, operation of the locking mechanism may be impeded, thus diminishing the lock’s efficiency and protective capability. Even though a lock is new, it is always a wise precaution to have the lock cylinder examined by a competent locksmith, since the protective capacities may

vary widely from one lock cylinder to another. The locksmith is usually the best qualified person in a community to judge the relative merits and capabilities of locks, and consulting him in these matters is simply taking advantage of his specialized knowledge. The Rim Deadlatch. The rim type of deadlatch

(Figure 2) is a rather uncommon

function in a rim

lock, but it is available, and when a rim latch is used on a door without glass, it should be of the dead-

latching type. As in other versions of the deadlatch, the rim deadlatch may be recognized by the presence of a small auxiliary latch or plunger that deadlocks

oo

_

Figure 1. THE MortisE DEADLATCH

This is the most common version of the mortise deadlatch. Other versions exist, but they are less common and ordinarily are less suitable for residential use. Features listed here are essential if proper protective capabilities are to be achieved. Their presence and proper functioning should not be taken for granted but should be verified by test. 1. Pushbuttons lock or release the outside knob. The inside knob is always free to operate the latch bolt. The latch bolt may be retracted from the outside by the knob when the lock is unlocked or by the key when the pushbuttons are set. 2. The pushbuttons must be inoperable when they are set in the locked position and the auxiliary latch is depressed. An effective alternative means of guarding the pushbuttons (used in the lock shown here) requires that the inside knob be turned slightly to release the pushbuttons so they may be moved from the locked position. This method of guarding the pushbuttons is independent of the position of the auxiliary latch. 3. The auxiliary latch, when depressed by the strike plate, guards the latch bolt against end pressure. It must also provide a means for guarding the pushbuttons unless they are guarded by some other means, such as described in the preceding paragraph. Other features may be found in various versions of these locks, and some may make a substantial contribution to the effectiveness of the lock in terms of increased protection or durability. Those listed above, however, are essential and should not be sacrificed in

order to obtain a lock with other desirable features or conveniences. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

15

16 / How to Burglar-proof Your Home

the latch against end pressure when depressed by the strike of the rim lock.

Some rim locks may be simple springlatches that convert to a deadlocking arrangement simply by turning the key or the inside turn knob in the reverse of the direction required for unlocking. This type of lock requires a special attention in locking that is extremely easy to overlook. As a result of human error, rather than failure in the adequacy of the lock mechanism itself, such a lock all too often fails to perform to the full extent of its designed capabilities. If sufficient care is taken in locking this type of lock, it is quite effective, but in situations where more than one person may be locking the door, the probability that the door may be locked improperly is considerably greater. Rim locks of this particular mode of operation should be avoided on that account. The Cylindrical Deadlatch. The cylindrical—key in the knob—type of deadlatch (Figure 3) may be recognized by the presence of an auxiliary locking plunger along the flat side of the latch bolt. This plunger, like the auxiliary latch, never enters the strike pocket. Indeed, it must not enter the pocket of the strike, or the deadlocking mechanism—that which allows the latch bolt to resist end pressure— will not function. Testing may be accomplished in a manner similar to the testing procedure for other deadlatches—by depressing the deadlocking plunger very nearly to the depth to which the strike plate depresses it when the door is closed, then pressing the latch bolt with a thumb or finger to test its resistance to end pressure. It should, by all means, resist a very firm end pressure and the latch bolt should come to a solid stop once it has retracted sufficiently to engage the deadlocking mechanism. The deadlocking plunger, of course, remains in its partially de-

Figure 2. THE RIM DEADLATCH

1. In this lock, the latch is retracted by the thumbturn knob from the inside or by the key from the outside. 2. The latch is kept in the retracted position by the slide button on the lock case. 3. The auxiliary latch deadlocks the latch bolt against end pressure. Other versions of this lock accomplish deadlocking without the use of an auxiliary latch. They use an extra turn of the thumbturn knob or key to extend the latch bolt slightly more than its normal extension, and this converts the latch bolt into more of a deadbolt than a deadlatch. In appearance and other features, they are indistinguishable from the springlatch or night latch function shown in Figure 25. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

17

18 / How to Burglar-proof Your Home

pressed position throughout the testing procedure. Since cylindrical deadlatches are subject to a number of inherent deficiencies in various manufactures and models, it is advisable to have them inspected by an expert.

The installation of all forms of the deadlatch is critical. The latch bolt must always be free to pro-

trude to its full extension into the pocket of the strike. The deadlocking auxiliary latch or plunger must never enter the strike pocket, no matter how rigorous the conditions that are imposed on the door. In addition, several requirements in the installation of the lock in the door itself are extremely important, and because of their diversity, it is recommended that these items be installed or checked carefully by a competent locksmith. Deadbolt

Locks

As aclass, the deadbolt is one of the most simple, positive, and effective means of locking a door, but even in this function, quality may vary rather widely with a consequent variance in the reliability of the unit. The common clue to recognition of a deadbolt lock is the fact that the bolt is square rather than tapered like the latch bolt. A springbolt function does exist that has all the configuration and apparent characteristics of a deadbolt, but the bolt is extended automatically when tripped by the key ora turn knob on the inside of the door (unless a key is used there also) and this bolt springs out of its own accord to the

full extent of its travel. At that time, it may or may not be deadlocked by a concealed mechanism, similar to that used in the internal portion of a deadlatch. Technically, if a square bolt is secure against end pressure whenever

it is fully extended, the lock is a

Figure 3. THE CYLINDRICAL DEADLATCH

A common type of cylindrical deadlatch is shown here. Many other versions are equally effective in locking a door, but many are intended for other purposes and frequently are somewhat more restrictive as to mode of operation than is necessary in locks for residential use. Features ordinarily appropriate for residential use are as follow: 1. Both knobs operate the latch bolt unless the outside knob is fixed by operating the thumbturn or pushbutton in the inside knob. The thumbturn is released manually to free the outside knob. Pushbutton types usually are released by simply turning the inside knob. Operating the key from the outside either retracts the latch or releases the outside knob or both, depending on the manufacture and model of the lock. 2. The deadlocking plunger is depressed by the strike plate to secure the latch against end pressure. The deadlocking plunger must NEVER enter the strike plate pocket. Illustration courtesy of Eaton Corporation, Division.

Lock and Hardware

19

20 / How to Burglar-proof Your Home

deadbolt; if it does not resist end pressure when so extended, it is a springbolt. In general, neither the springbolt nor the deadbolt with this mode of operation is as consistently reliable as is the deadbolt that is operated throughout the full extent of its travel by the positive action of the key or thumbturn, because anything that stops a spring-operated deadbolt in its travel before it is fully extended (such as an obstruction in the pocket of the strike) may cause the deadlocking mechanism to malfunction. The true deadbolt function may be differentiated from the spring-operated variety by turning the key in the lock while maintaining a light pressure on the end of the bolt in opposition to the extending operation produced by the key. If this operation pro-

duces full extension of the bolt and the key is withdrawn from the lock while maintaining the end pressure, leaving the bolt fully extended despite that pressure, then the lock is a true deadbolt and is in functional operating condition. Any lock with a deadbolt function should be installed so that the pocket of the strike which the deadbolt enters is completely free and clear of obstructions. It should be at least an eighth of an inch deeper than the deadbolt will penetrate at maximum extension. This extra space in the bottom of the strike pocket takes care of hinge wear and the expansion and contraction of the door or building and helps assure full extension of the deadbolt at all times. Five common deadbolt configurations, suitable for installation on doors without glass, are shown in Figures 4 through 8. The Mortise Deadbolt. Of all the deadbolt configurations, the mortise unit (Figure 4) is commonly

considered the most rugged and dependable. The modern mortise deadbolt may be recognized by the fact that it has an exposed front on the edge of the

Entry Doors without Glass / 21

door that is usually eight inches long* and incorporates a pin tumbler lock cylinder on the outside surface of the door, above the knob. The older type of mortise deadbolt requires a bit key that has the appearance of being constructed on a round rod, usually of steel. It may be quite an effective lock, or it may be of an inferior type capable of being operated by a so-called skeleton key. Any of the older types of lock requiring a bit key should be inspected by a competent locksmith to determine the amount of protection it will give. Some locks of this type were

whereas

exceptional

others

and gave excellent protection,

merely

presented

an

illusion

of

protection.

The testing operation for deadbolts previously described (maintaining an end pressure on the deadbolt while operating the key and thumbturn to extend the bolt) is extremely important in the deadbolt function, since wear in certain deadbolt designs may cause a malfunction if there is any pressure whatever against the end or side of the deadbolt while it is being thrown. A slight pressure on the door in the direction that opens the door may cause

the bolt to scrape along the edge of the strike plate or its pocket while the bolt is in the process of extending and is often sufficient to cause such a malfunction in an imperfect deadbolt mechanism. Such a deficiency must be corrected promptly, and the correction must be made in the internal mechanism of the lock if an adequate degree of reliability is to be restored. While the physical strength of the mortise deadbolt lock nominally is the greatest of all locks, a large measure of that strength depends on the strength *Eight inches is the commonly used dimension specified by the American Society of Testing Materials. Other sizes do exist in modern production but are less common.

Figure 4.

A MorTISE DEADBOLT

The version of the mortise deadbolt shown here is suitable for use on doors without glass, subject to limitations described in the text. In operation, the latch

bolt is operable by the knob from either side at all times. The deadbolt is extended or retracted by the key from outside or by the thumbturn on the inside. Note that this lock does not and SHOULD NoT have pushbuttons for locking the outside knob. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

22

Entry Doors without Glass / 23

of the door in which it is mounted. The resistance of the mortise deadbolt to forced entry, therefore, depends on the strength of the lock, the physical strength of the door itself, and the amount of strength

left in that door after its edge is mortised out to accept the body of the lock. Usually this problem is more acute in wood doors, but occasionally it creates

a problem in metal doors as well.

The Rim Deadbolt. The rim deadbolt is customarily used on wood doors, particularly those that are not thick enough to accept a mortise deadbolt without seriously weakening the door. The rim deadbolt is available in two separate and distinct subtypes. The rim deadbolt proper (shown in Figure 5) is similar to some mortise deadbolts internally, although it is contained in a much smaller case and is mounted on the inside surface of the door instead of being recessed into the edge of the door. The common configuration for an unglazed door (one with no glass) has the rim deadbolt operated by the turn knob from the inside or by key from the outside. This lock utilizes a pin tumbler lock cylinder that has a cylinder connecting bar to link the operation of the cylinder with the deadbolt mechanism. Unlike the mortise deadbolt, the rim deadbolt has no knob and latch mechanism incorporated in it. Its sole purpose is to provide a locking function for the door. As may be seen in Figure 6, the second type of rim deadbolt looks different from other deadbolts. It is commonly known as the jimmy-proof rim lock and is readily recognizable by having fingers on both the lock case and the strike. These fingers interleave as the door is closed. A deadbolt is extended out of the fingers of the lock case by the action of the key to enter the fingers of the strike, locking the lock case and the strike securely together. This particular configuration of the rim deadbolt is highly desirable and

24 / How to Burglar-proof Your Home

Figure 5. A RIM DEADBOLT The bolt is extended or retracted from the outside by key or from the inside by a turn knob (thumbturn). The bolt is deadlocked in both the extended and retracted positions. Some of these locks may contain hardened rollers imbedded in the bolt to prevent sawing. The deadlocking device is engaged only when the bolt is fully extended or fully retracted. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

is considered one of the most effective of rim locks when the quality of the particular device used is good (as is true of any rim lock) and when it is anchored very securely to the door with the strike anchored equally securely to the door frame. One unit of this type features installation by bolting the lock together through the door, which makes an especially sturdy installation as it is less dependent on the strength of the material of which the door is made. The Tubular Deadbolt. The tubular deadbolt (Figure 7) is installed in a round hole drilled into the edge of the door. It commonly has a rectangular front, usually two and one-fourth inches in height. The bolt

Entry Doors without Glass / 25

itself may be truly rectangular in shape, or its corners may be somewhat rounded. It is operated from the outside by a pin tumbler lock cylinder, usually of the rim type or very similar, connected to the deadbolt

tube

by a cylinder

connecting

bar

(usually),

which is either identical or similar to that of the conventional rim cylinder. A word of caution is in order. Locks of this type are on the market that utilize a disc tumbler rather than a pin tumbler lock cylinder. The protective capabilities of the disc tumbler locks

Figure 6. A JiMMy-PROOF RIM LOCK

The deadbolt of this lock secures the lock case to the strike plate when activated. Activation of the device is by key from the outside or by turn knob from the inside. The small plunger at the end of the lock case activates a shutter that closes off access to the lock if the lock cylinder is forcibly removed from the door. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

26 / How to Burglar-proof Your Home

nearly always are far less than those of the pin tumbler type. Because of the small physical dimensions of most parts in a tubular deadbolt, it is particularly important to avoid using this type of lock if it is made from die cast materials of the grade commonly known as pot metal. When inferior metals or other inferior materials are used in the critical wear or stress portions of the lock, it could prove decidedly inadequate when under attack. The Surface Bolt The surface bolt shown in Figure 8 is suitable for locking doors without glass from the inside, but since it has no outside operation, by key or any other method,

it is often inconvenient.

the common sliding bolt surface of the door with that slides back and forth control the bolt turns at

The surface bolt is

that attaches screws. It has in a slot. The a right angle

to the inside a round bolt knob used to in the slot to

deadlock the bolt. When this type of bolt is used, it should be of sufficient size and strength to resist whatever force an intruder may be able to bring to bear. This means that a bolt of this type should be somewhat larger than is customarily used. It is suggested that a bolt of this type have a bolt diameter of at least five-sixteenths of an inch and that the housing for the bolt be at least four and one-half to five inches long for any effective degree of strength. Additionally, the bolt housing should be assembled by the manufacturer so that it will not pop apart when a severe strain is applied. If welding is required to achieve this strength, it should by all means be done. Naturally, the method used to apply the bolt to the door should provide strength consistent with these objectives, even if this means drilling extra holes in the flange of the bolt housing and installing extra, and possibly stronger, screws. Obviously, the

Figure 7. A TUBULAR DEADBOLT The bolt is deadlocked in both the fully extended and the fully retracted positions. Operation is by key from the outside or by turn knob or thumbturn from the inside. Operation of the tubular deadbolt in extending or retracting the bolt is entirely powered by the operation of the key; however, a subtype that might more properly be called a deadlocking springbolt appears to be identical. The deadlocking springbolt utilizes the action of the key to trip the deadlocking mechanism,

which

keeps the bolt retracted, and the bolt is then extended by the action of a spring. The true deadbolt type, operating entirely by the force supplied by the key, is usually somewhat more reliable, since improper closing of a door may cause the bolt to stop before it is fully extended and deadlocked. Illustration courtesy of Eaton Corporation Division.

Lock and Hardware

28 / How to Burglar-proof Your Home

strike for the bolt must provide equal strength, even though similar extraordinary measures may be required. Customarily, bolts of this type are used only for doors that open inward because of the difficulty of providing effective strike strength in outward-opening doors. If it is necessary to use a bolt of this type on an outward-opening wood door, the strike provided with the bolt should be discarded and a piece of tubing inserted through a hole drilled in the appropriate location in the door frame. This drilled hole and the tubing should continue on through the door frame and into the studding behind the frame. The hole drilled through the door frame must fit the

outside diameter of the tubing very tightly—tightly enough to require that the tubing be driven into place. The tubing used should be large enough in inside diameter to accommodate the bolt with just about the same amount of play as that allowed by the original strike. It should be just long enough to permit the end of the tube to be flush with the surface of the door frame when the tube is firmly in place. An installation of this type should never be made on an outward-opening door merely by drilling into the door stop or frame unless tubing is used as described; this will prevent the wood from splintering when sufficient outward pressure is applied to the door. The sole exception to this rule occurs if the door frame is of metal and does provide realistic strength using such a method. The Mortise Bolt

The mortise bolt (Figure 9), though not strictly a deadbolt, may be used for inward-opening doors. It should not be used for doors opening to the outside, because the bolt is set into a hole drilled into the edge of a wooden door, and the bolt moves into a strike or

Figure 8. A SURFACE BOLT Such a bolt, when used, should be of sufficient size

and strength to accomplish its objective effectively. In order to achieve adequate strength in a bolt of this type, it often is necessary to add weld in the areas shown in white. A bolt of this type should never be used on a door that may require access from outside when the door is locked.

Figure 9. A MortIse BOLT

Such bolts should be used only on doors that open inward and that do not require access by key or otherwise from outside when locked. 29

30 / How to Burglar-proof Your Home

pocket in the door frame, which makes the bolt vulnerable to a prying action in the gap of the door, or to sawing. If the bolt is in good condition, the mechanical advantage offered by the gear system, plus the friction provided in the bolt and knob, is sometimes sufficient to inhibit such a mode of attack. But if the unit is worn or has been lubricated, that mechanical advantage is largely lost. If the door opens to the inside and the door stop is securely attached to the door frame, the use of a mortise bolt is quite plausible. It is operable only from the inside by the turn knob and, having no outside function or exposure, is not vulnerable to the modes of attack previously described. Its practical uses are substantially limited to doors that are not required for reentry, and those doors must be without glass and open inward. Secure Installation of Lock Strikes

We have seen that door locks must exhibit certain characteristics of strength and reliability to be effective and that the alignment of the strike may have an effect on the reliability of the lock. The strength of that strike and the firmness with which it is installed also may influence the effective strength of the lock. The strike should be as strong and as firmly mounted on the door frame as the lock is in the door. For many lock types, the frame should be reinforced and/or the attaching screws of the strike should be long enough to anchor into the studding or material behind the door frame. If the normal means of installing the strike furnishes strength comparable to that supplied by the lock, no special methods are required,

and the usual installation

perfectly adequate.

method

may

be

3 Entry Doors with Glass Glazed

exterior or entry doors—those

that are

partly glass—pose a much greater degree of vulnerability to burglary than do unglazed doors. The most obvious reason, of course, is that the glass can be broken or cut by a glass cutter, allowing the burglar to reach in and unlock the door by simply turning a knob or thumbturn. If the glazed area is large enough, he may actually crawl in through the opening left when the glass is broken out. The most common method, however, is breaking the glass to reach in and unlock the door, because most homes are

equipped

with

locks

that

make

this

technique

possible. Another hazard of glazed doors is the possibility of someone's removing the putty or the retain-

ing strip on the outside of the door that holds the glass in place, removing the glass, and reaching or 31

32

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Entry Doors with Glass / 33

climbing through to gain entry. Exterior doors with glass should be glazed in such a way that the glass cannot be removed from the outside, even if drastic alterations to the door are required to achieve this objective. Special Glass

The vulnerability of glazed doors is significantly reduced when the glass is of a recently developed burglary resistive type or is wire glass and is removable only from the inside of the door. Wire glass has a wire mesh imbedded in the glass itself. The mesh keeps the glass intact if broken and resists attack by glass cutters. More recent versions of wire glass are often attractive, as the imbedded wire need not be of the older chicken-wire type commonly associated with wire glass. To the contrary, some of the modern versions of wire glass are quite attractive. The wire design serves an_ aesthetic purpose as well as a functional one, as shown in Figure 10. Burglary

resistive glass is a much

more

recent

development, known in one version as Secur-Lite glass, manufactured by Amerada Glass Company and shown in Figure 23. It is somewhat more expensive than either conventional glass or wire glass, but it is much more effective in resisting burglary. It is

superior in this respect even to wire-reinforced glass. It is thicker and is laminated with layers of resilient plastic interspersed between layers of glass in much the same way the safety glass of an automobile is laminated but with considerably greater strength. Actual thickness of the glass varies according to the size of the window in meeting minimum protecticn requirements. Thicker glass may be used to achieve

34 / How to Burglar-proof Your Home

greater protection than the minimum protection stan-

dards required for insurance or Underwriters’ Laboratories’ requirements, if desired. For most practical purposes, a door properly equipped with burglary resistive glass may be considered as strong as a door without glass. To a somewhat lesser degree, this is also true of wire glass. If the glass is not one of these types, the locks should be selected from those appropriate to doors with glass, discussed below. Locking Requirements for Doors with Glass Locks used on glazed doors should be of the kind that cannot be unlocked without the key from either side in case the glass is broken and the burglar reaches through. Merely turning a knob should not open the door. For this reason, the deadlatch function is not recommended for glazed doors. The deadbolt function with a keyed lock cylinder on both sides of the door should be used for this purpose. The use of a key to lock or unlock a door from the inside is admittedly somewhat more difficult and inconvenient than is the use of a thumbturn or simply turning the inside knob and is less convenient than using a thumbturn or pushbutton to set the locking mechanism. The requirement of a key from the inside to allow the door to be opened reduces drastically the vulnerability to burglary. A lock of this type does present a hazard to the homeowner in the event of fire, so use of either of the glasses mentioned earlier becomes doubly attractive. Without special glass, the double cylinder deadbolt function becomes the only suitable type of lock for use in a glazed door. The configurations commonly available and suitable for use in glazed doors include the double cylinder mortise

Figure 11.

A DOUBLE CYLINDER

Mor Ise DEADBOLT

Although both knobs are always free on this type of lock, entry or departure requires the use of a key when the deadbolt is in the locked position. This type of lock provides a high degree of burglary resistance but may pose unacceptable safety hazards in the event of fire or emergency. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

35

36 / How to Burglar-proof Your Home

Figure 12.

A DOUBLE CYLINDER RIM DEADBOLT

Operation of this lock’s deadbolt requires a key from either side. Although this mode of operation is necessary for effective burglary resistance by glazed doors, it may also present safety hazards. In order to obtain maximum burglary resistance, special techniques must be used in the installation of the lock case as shown in Figure 14. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

deadbolt shown in Figure 11. The use of the two lock cylinders prohibits the mere use of a simple thumbturn to release the lock, thus affording a measure of burglary protection even though the glass may be broken. The rim deadbolt and the jimmy-proof rim lock are both available with an additional lock cylinder that is rigidly mounted on the inside surface of the lock case, usually protruding from the lock case by nearly the full length of the lock cylinder (Figures 12 and 13). The lock cylinder occasionally is manufactured as an integral part of the lock case but more commonly is a conventional cylinder applied in a tamper-resistant manner. In installation, a double cylinder rim lock should be applied to the door in

Entry Doors with Glass / 37

such a way that the mounting screws are inaccessible while the door is closed and locked. But this is a matter of the design of the unit. If the lock design requires that the lock be applied with accessible screws, those screws should be one-way screws or of the Phillips-head variety and the slot in the screws should be drilled out after installation to such an extent as to be unusable for a screwdriver. (See Figure 14.) This prevents a burglar from breaking the glass and removing the lock from the inside of the

Figure 13.

A DouBLE CYLINDER JIMMY-PROOF RIM Lock

Like other double cylinder deadbolt type locks, this unit enhances the burglary resistance of glazed doors but poses safety hazards in the event of fire. Special attaching screws, as shown here, or special treatment of the screws, as shown in Figure 14, will be required to

realize the full protective capabilities of this type of lock. Like any other rim lock, the outside lock cylinder must be very firmly mounted for maximum protection. Illustration courtesy of Eaton Corporation, Lock and Hardware Division,

Figure 14. MAKING SCREWS TAMPER-RESISTANT

Top left: Top right:

Center left: Center right:

Lower left: Lower right:

38

Slotted countersink head screw. The equivalent of same after the slot has been battered closed, using the ball end of a ball peen hammer. Countersink head screw with Phillips slot. The equivalent of same after the Phillips slot has been drilled out. Slotted round-head screws. Factory type one-way screw. This is the equivalent of the slotted roundhead screw except that the head is partially cut away when the screw is made. This is done in such a way that the screw may be inserted in the normal way, but the screwdriver will slip out of the slot and up an inclined surface if the rotation of the screwdriver is reversed.

Figure 15.

A DUAL CYLINDER TUBULAR DEADBOLT

Operation of the deadbolt is by key from either side of the door. As with the single cylinder deadbolt, the types that have the bolt extended by a spring tension are to be avoided because of the danger of the bolt’s striking an obstruction before it is fully extended, with a resultant failure of the deadlocking mechanism to become operational. As explained in the text, certain safety factors should be carefully considered before using a double cylinder deadbolt or other type of lock that requires a key to operate from the inside. Additionally, such a lock

requires more time to lock in the event of an immediately impending emergency when the proper key must be located and inserted into the lock’s inside cylinder before the door may be locked. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

39

40 / How to Burglar-proof Your Home

door with a screwdriver. In terms of legitimate servicing of the lock, it means that the heads of the screws must be completely drilled off if the lock is to be removed, so servicing at the time of installation should be thorough. The tubular deadbolt, shown in Figure 15, is available with dual lock cylinders for use on glazed doors. The cylinders for this type of lock often have one screw installed from the outside of the door and the other from the inside to clamp the cylinders together. This is quite satisfactory for these dual cylinders if the slots of these screws are destroyed, disfigured, or filled in such a way as to prevent the use of a screwdriver or Allen wrench to remove the cylinders. This should be done on both sides of the door, because once the glass is broken both cylinders are accessible, and if these screws are removed, the lock can be operated without recourse to a key. Considerations Regarding Double Cylinder Locks Before double cylinder locks are chosen for a door, two factors should be weighed against each other and the differences satisfactorily resolved. One is the risk of burglary through breaking the glass and reaching in; the other is the safety hazard posed to the occupants of the building when the door is locked. The need for a key and the possibility of having to hunt for a key to get out of the building in the event of a fire, perhaps in the middle of the night, poses a safety hazard of considerable importance. For this reason, it is strongly suggested that such a door be fitted with wire glass or burglary resistive glass whenever possible, so that it may be treated as an unglazed door that does not require two-cylinder

Entry Doors with Glass / 41

operation. Ordinarily, this solution is preferable to using a two-cylinder lock. Some fire safety and building codes now prohibit the use of double cylinder locks in certain circumstances, so one should check these codes before installing locks.

5

a

are

9

a

“eke s =

if

4 Other Considerations Regarding Doors A number of important considerations, in addition to the mere selection and use of appropriate locks, help make the difference between a door that is locked and one that is secure. One of those considerations is the way the door itself is made. We have touched upon this aspect of door security briefly several times before, so perhaps we should consider this factor in further detail before passing to other matters.

Types of Doors

The installation requirements for various types and configurations of locks are sufficiently diverse that not all types of doors will accommodate the installation requirements of all types of locks. Limitations imposed by certain types of doors on the lock 43

44 / How to Burglar-proof Your Home

choice are often quite restrictive and limit the selection of locks that otherwise would be suitable. When this situation creates a problem in the protective capability of the door, consideration should be given to replacing the door. Other problems also may be inherent in certain doors, so we shall attempt to consider some of those problems, too. Panel Doors

The term “panel door” refers to a relatively oldfashioned type of door that has thin wooden panels inset in a heavy, solid wood framework (Figure 16). If

the material in the panels is so thin as to be easily broken or kicked out of a door, then the types of locks considered for such a door should be the same as those considered for a glazed door. A panel door frequently will accept a mortise type lock, but when installing a mortise lock in a panel door, careful consideration should be given to how much wood must be cut away from the stile of the door. If the amount of wood that is to be cut away is sufficient to weaken the door materially, then another type of lock such as a rim, tubular, or cylindrical lock should be consid-

ered. Installation of these locks usually does not weaken the stile of a door as seriously as does the installation of a mortise type lock. Hollow-Core

Doors

The hollow-core wood door (Figure 17) is the more modern and currently popular equivalent of the panel door. It consists of two slabs of plywood veneer placed over the framework of the door. The interior of the door, between the stiles and under the plywood veneer, may have very little reinforcing, or it may be well reinforced. It is difficult to make this

EE ae

ee

DE

TSS

EY

Figure 16. PANEL Doors

A panel door consists of two solid vertical stiles, one at each edge of the door, with heavy rails at top and bottom, and a rail separating each panel from the next. Some such doors have the panels in a vertical format, as at the left, and others may have panels in a horizontal format, as at the right. Occasionally both horizontal and vertical panels are combined in the same door. In glazed doors of this type, some of the panels are of glass instead of wood.

46 / How to Burglar-proof Your Home

determination from the external appearance of the door. The depth to which the side (or edge) stiles extend into the door also varies considerably from one door to another. In some cases, the side stile on the edge of the door may extend considerably less than two inches into the door. This depth does not afford sufficient bearing to accept any suitable lock, so a reinforcement piece usually is attached behind such a stile. Its size customarily is merely sufficient to accept a cylindrical type lock or latch and is seldom sufficient to accept a mortise lock satisfactorily. Rim and tubular locks, because they are mounted above the usual knob position, will miss this reinforced area of the door and find little or no support. When this kind of door is used, it is usually better to use the cylindrical type of lock, as the zone reinforcement customarily provided in these doors during manufacture is more consistently compatible with this purpose. As a guide in determining the adequacy of a hollow-core door in terms of burglary protection, the thickness and sturdiness of the veneer overlay should be considered as a governing factor, since the adequacy of its resistance to forced entry will have an important bearing on lock selection and security in general. Other doors of this type may provide adequate mounting for any type of lock, since some of them have much wider stiles and contain cross-member reinforcing as well. Determination of the width of the stiles and the presence of cross-member reinforcing may be determined in a generalized way by rapping the door; a hollow sound will mean no reinforcing is present under the veneer. A solid sound may mean that solid wood reinforcing is present at that point, or it may mean that the door is stuffed with cardboard

Figure 17.

A HoLLOw-Core Door

A hollow-core door may have a substantial framework comparable to that found in panel doors, but more commonly the framework is lighter, as shown in this illustration. Usually a reinforcement is provided in the area in which a lock or knobset is to be installed. In some doors, deficiencies in framing may be partially offset by improved lock area reinforcement and a heavier veneer. Determination of stile size, areas of stile size, and areas

of reinforcement frequently may be grossly determined by a systematic rapping (unless the door is stuffed). Areas of the door without reinforcing will give off a hollow booming

sound rather rapidly as areas

CS

RE

1

of underlying support are approached. When a door is stuffed, areas of underlying support

may be rather difficult to determine. Usually the stuffing material is corrugated paperboard or a similar substance. Frequently this material is treated to make it fire- resistant. It also provides improved insulation. Other factors being equal (reinforcing and veneer thickness, for example), such a door has little more

burglary resistance than does a similar door without such stuffing, unless a layer of wire mesh is imbedded in the stuffing material or included with it. 47

48 / How to Burglar-proof Your Home

or some other insulating material. If a door sounds solid in all places, it may be a solid-core door, but it is well to suspect that the door may be hollow-core with at least part of the area stuffed. A well-attuned ear can sometimes determine where such stuffing leaves off and reinforcing begins, but such determinations are quite likely to be somewhat unreliable at best. Solid-Core Wood Doors

The term “solid-core,” as applied to doors, simply refers to a door that is solid wood all the way through. It may be made in any of a variety of construction types. It may be a plank door, made from overlapping planks that are tongued and grooved to one another in two or possibly three thicknesses. The solid-core door may also be of virtually solid plywood with side rails inlet into the edge. One of the important aspects of a solid-core door is the fact that it will accept a mortise lock satisfactorily. It will, of course, accept any of the other lock configurations and types as well. Solid-core doors are preferable for use as entry doors wherever possible; indeed, they are required by building codes in many circumstances.

Sometimes stuffed doors are sold as “solid-core wood doors.” They are wood, and they do have a solid core—even though that core is not wood. When one is buying a solid-core door, it is advisable to

specify a solid-core wood door with a wood core. Metal Doors

Metal

doors,

although

they are rarely used in

home or apartment construction, are usually the most

desirable of all from the standpoint of burglary resistance. They are cut for lock and hinges at the factory

Other Considerations Regarding Doors / 49

and manufactured to accept a specific configuration of lock. Usually they are also cut to accept a specific manufacture and model of lock. The exception is those doors manufactured to accept cylindrical lock sets. Models and manufactures of locks may be exchanged fairly easily in metal doors that are cut to accept cylindrical lock sets, although there are some

restrictions such as backset, case diameter, and the like. Some doors that are prefit for mortise locks will accept various manufactures of lock with almost equal ease, but when a door has been precut for a specific lock, considerable work is likely to be required to recut the door to accept a different lock. Doors that have been factory precut to accept a mortise lock of nonstandard dimensions will accept no other manufacture or type with different dimensions without the expenditure of what is usually a prohibitive amount of work. That work carries with it the risk of disfiguration of the door to the point of virtual destruction of its worth. Metal doors usually are not intended to be used with tubular type locks or mortise bolts. A surface bolt may be applied to a metal door, but the means of locking provided by the manufacturer is usually superior to any afterthought provisions by the homeowner or tenant. The provision for a lock type by the door manufacturer nearly always provides sufficient latitude for a variance in lock function within that type, so the householder usually has some latitude in the selection of an operating function or mode. Locks that are supplied with metal doors are not always the best choice for the particular conditions in which they are actually put to use, nor are they necessarily of the best, or even adequate, quality. It is therefore suggested that the lock type be considered with care by the householder and that the

50 / How to Burglar-proof Your Home

quality of the lock and the adequacy of the installation in that particular door be carefully checked by a competent locksmith to detect any shortcomings. Metal doors, while they almost invariably provide adequate physical strength, may be somewhat vulnerable to tampering due to attempts by the manufacturer to introduce versatility of lock choice into the manufacturing criteria.

Other Factors Affecting Door Security

Other factors also affect the degree of protection provided by entry doors. Some of these may negate or enhance the other measures taken to make a door into an effective security barrier. Some of those factors will be discussed briefly here, more to bring them to the attention of the householder as being relevant than to attempt to detail all of their possible merits and shortcomings. They do deserve serious consideration. Door Frames and Stops

Metal door frames usually have integral stops. With the stop actually a part of the door frame, integrity of stops is no problem. If the mounting and/or grouting of a steel door frame is competently done, frame rigidity is usually adequate. Aluminum frames, because of the lesser rigidity of that metal and some of its alloys, should be carefully tested. All too often, metal frames may be carelessly installed and permit excessive give when they are subjected to prying. This possibility should be carefully checked and corrected where necessary. Wood door frames, unlike metal ones, pose a number of potential problems. Since the doors on

Other Considerations Regarding Doors / 51

most residences or apartments open inward, the matter of the door stop is relevant because it is exposed to attack from the outside. If the door stop is an integral part of the frame, there is little to be concerned about, provided such a frame is installed with adequate tolerances. If the door stop is of the applied type, the probability is that such a stop is applied by the use of finish nails. If, upon testing, this is determined to be the method of application, the stop should be carefully pried out, away from the door frame, and some very strong glue inserted to bond the stop firmly to the door frame before it is nailed back to the frame. If this job is carefully done, the stop and frame will then become essentially a one-piece unit. A door stop thus firmly installed helps keep a potential burglar from gaining access to the lock through the edge of the door. It will not eliminate a skilled burglar, but not all burglars are that skilled. Wood door frames usually have a certain amount of give or spring in them when subjected to forcible attack. This springy characteristic can be taken advantage of by burglars in the technique known as jimmying

or prying a door open in such a way as to

separate the door from the frame to a sufficient degree to disengage the locking device. In order to frustrate this technique, it is advisable to reinforce the door frame immediately above and below the position of the strike plate. On the opposite side of the door frame, it is advisable to reinforce the frame immediately behind the point where the hinges are mounted. Properly done, this eliminates essentially all give by which a door may be jimmied. On both edges of the door, reinforcement of the frame should be done by inserting a wood filler of sufficient thickness to take up all space between the door frame and

52 / How to Burglar-proof Your Home

Figure 18. FULL Mortise Butt, LOOSE PIN Courtesy of Hager Hinge Company.

the nearest structural portion of the wall behind the

door frame; customarily, this will be a two-by-four wall stud or solid masonry. Unless this job is done at the time the building is constructed, it will be necessary to remove the inside door casing to gain access to the areas to be reinforced. The time is well spent. If door frames or stops are chipped, worn, or scraped to the point where they will permit access to the locking mechanism, the door frame should be replaced or suitable and sturdy repairs made.

Other Considerations Regarding Doors / 53

Door Hinges

Door hinges on outward-opening doors are another point that may be attacked by a burglar. On inward-opening doors, it often is sufficient if hinges are reasonably sturdy, firmly mounted, and wearresistant to ensure the proper meeting of the locking mechanism with the strike. On doors opening inward, the hinges should be sufficiently sturdy to resist the prying force a burglar could reasonably be expected to be capable of exerting with a tool such as an ordinary carpenter’s pry bar. This is a common tool for burglary. Hinges should be mounted with screws that are adequate to prevent such a prying attack from ripping the hinges from the door with any degree of force less than that which would cause the destruction of the door or hinges. Often, inadequate hinges or hinge screws are the weakest link in the protection offered by a door. Full Mortise Butts. For doors opening outward or With the Hager Non-Removable Pin, a small set screw in the top knuckle of the hinge barrel anchors into a hole tapped in the hinge pin. It is positioned so that it cannot be reached unless the hinge is open, merely remove the set screw and tap pin from bottom in the usual way. The non-removable pin is available on all Hager butt hinges. Specify symbol NRP.

Figure 19. NONREMOVABLE

PIN FEATURE

Most commonly, this feature is used on full mortise butt hinges. Courtesy of Hager Hinge Company.

54 / How to Burglar-proof Your Home

doors with glass, there are other requirements, of which those relating to the hinge pin are of primary importance. The hinge pin or pivot pin holds the two halves of the hinge together and provides the swiveling action that occurs as the door is opened and closed. (See Figure 18.) Because removal of the hinge pin would permit separation of the two halves of the hinge, this pin must be provided with safeguards against its removal. This safeguard is usually in the form of a screw in one knuckle of the hinge, and it is so positioned as to be invisible and inaccessible when the door is closed. When the retaining screw is tightened with the hinge pin in proper alignment, the screw seats in a groove or other recess in the hinge pin.

In some manufactures, the hinge pin retaining screw is there, but only as a technicality, so it is well to determine that the strength of the retaining screw is adequate and that its engagement with the hinge pin is positive. The retaining screw should be checked periodically to be sure that the screw is properly in place and has not become so loose as to permit the hinge pin to be removed. Hinges made in the manner described here are referred to as nonremovable pin hinges (NRP). Nonremovable pin hinges (Figure 19) customarily are found only in full mortise hinges, or, in the terminology of the trade: “full mortise butts with nonremovable pin.” Full mortise butts are also available and frequently found with loose pin construction—that is, lacking the hinge-pin retaining screw. Loose pin butts should never be used on an outward-opening door or any door with glass, since removal of the hinge pins would then permit the entire door to be removed from the frame, even though the lock is securely locked—most claims for various types of loose pin hinges notwithstanding.

Other Considerations Regarding Doors / 55

Figure 20. Fast RIVETED PIN (FRP) CONSTRUCTION

This type of hinge pin construction has both ends of the pin spin-riveted, making it permanent and secure. Courtesy of Hager Hinge Company.

Another form of full mortise butt has what is known as a fast riveted pin (FRP). These hinges have a pin riveted permanently in place in the hinge (Figure 20). Since the hinge pin is not removable without destroying the hinge, it furnishes even greater protection than that provided by the nonremovable pin construction. To the extent that it furnishes consistent protection virtually without regard to the fit of

the door in the frame, it is superior to all other types. To gain entry through an outward-opening door equipped with these hinges, it would be necessary to destroy all the hinges. Still other forms of full mortise butts are provided with a protective device called a security stud (Figure 21). This security stud consists of a metal

stud (or peg) that protrudes from one side of the hinge in such a way that the security stud enters a hole or pocket in the opposite side of the hinge as the door is closed. Security stud hinges provide an extremely high degree of protection with the reservation that the clearance of the door (the total gap on

Figure 21. FULL MortiseE BUTT WITH SECURITY STUD

The stud on the right side of the hinge enters the pocket on the left side as the door is closed. This results in locking the two parts of the hinge together any time the door is closed, even though the hinge pin may have been removed. This hinge is also obtainable with a nonremovable pin, which is recommended as a desirable extra when ordering these hinges, because an excessive gap in the fit of the door may partially nullify the effectiveness of the security stud. If such an excessive gap is found, it may be offset by building up the lock edge of the door or door frame in a manner calculated to make it burglar resistant. Illustration courtesy of Hager Hinge Company.

56

Other Considerations Regarding Doors / 57

both sides of the door inside the frame) must be and remain, when pried, sufficiently small to exclude any possibility of the pin being removed and the door slid over far enough to disengage the security stud from its pocket. Security stud hinges should be of the NRP type (equipped with a pin retaining screw), not only to help minimize this risk, but also .to provide twostage protection for the hinge. This causes more delay to a burglar trying to gain entry by attacking the hinges. The same reasons that make it desirable to equip security stud hinges with a hinge pin retaining screw likewise make it important for the screw to be checked occasionally to make sure it is fulfilling its purpose adequately. Reinforcement of the door frame to prevent springing the frame enough to disengage the security stud is extremely important if this type of hinge is to be used effectively. If an excessive gap exists in the lock edge of the door (enough to permit forcible disengagement of the security stud), a shim of appropriate size and configuration should be used to correct the condition. Half Surface Butts. The term “half surface butt” refers to a hinge that has one side, usually the door frame side, set between the door and the door frame (Figure 22). This is also true of a full mortise butt. With the half surface butt, however, the other half of the hinge protrudes out onto the surface of the door (or frame) and is attached there, usually by screws. Such hinges are commonly of the loose pin type, so the mere removal of the pin is sufficient to remove the door, though locked, from its frame. Since the half surface butt is also vulnerable to removal of the screws by which it is attached to the door, little would be gained by a nonremovable pin feature. If it is impossible to replace half surface butts

Figure 22. HALF SURFACE BUTT

Since half surface butts have exposed screws that make them vulnerable, they usually are equipped with loose pins. Illustration courtesy of Hager Hinge Company.

58

Other Considerations Regarding Doors / 59

with full mortise type hinges, a measure of protection can be provided by equipping the hinge with a hinge pin retaining screw and notching the hinge pin for it. The screws that attach the hinge to the surface

of the door should then be replaced with countersunk screws having a Phillips or an Allen type driving slot. When the attaching screws are securely

in place, the slots are drilled out to such an extent as to make the common means of removing such a screw ineffective. If still more protection is required for the door, it may be equipped with one or more homemade security studs to operate between the door and the door frame in a manner similar to the way the security stud operates ina security stud hinge. If this course of action is adopted, it is suggested that such studs be located so as to derive some protection from the bulk of the hinge. For inward-opening doors that contain glass, it should be remembered that not only is the lock vulnerable, but breaking the glass may (in some doors) provide access to the hinge pins as well. Where the dimension and configuration of the glass in an inward-opening door permit the removal of the hinge pins by breaking the glass, those hinges should be replaced with hinges that are protected against that contingency, just as would be used for outwardopening doors. Wire Glass and Burglary Resistive Glass Wire glass or burglary resistive glass will convert a glazed door into the equivalent of a solid door provided the installation of the glass is as sturdy and burglary resistant as the glass or door itself. Hardware requirements for a door properly equipped with either of these types of glass can be considered the same as for a door without glass.

60 / How to Burglar-proof Your Home Wire Glass

The wire glass most people think of is the older type with chicken wire imbedded in it. It is virtually devoid of any aesthetic appeal and is intended to serve a strictly utilitarian function. Although this type of glass is still available, more recent versions of wire glass are available in strikingly attractive, ornamental designs that blend pleasingly into the architectural unit (see Figure 10). Because of the more attractive wire configurations available and the wider varieties of glass in which the wire may be imbedded, it can be a strikingly attractive installation.

Burglary Resistive Glass Burglary resistive glass is made in much the same fashion as the windshield of an automobile. It is made of glass in multiple sheets with a resilient plastic bonded between them. The usual windshield glass consists of two pieces of glass with a layer of plastic between them. Burglary resistive glass, although of similar construction, is made much more sturdily than is that commonly found in automobiles. (See Figure 23.) Such glass, when installed, is rather difficult to differentiate visually from other kinds of glass. In appearance it is identical to ordinary glass, although the thickness of the burglary resistive glass is likely to be considerably greater, particularly in the larger sizes.* For most dwelling requirements, wire glass provides an adequate degree of burglary protection, and at less cost than burglary resistive glass. Con*“To meet Underwriters’ Laboratories’ requirements for burglary, a maximum size limit is imposed on each thickness of glass available. Thickness of the glass may vary from 9/32 to 7/16 of an inch, with the 7/16-inch glass available in sizes suitable for storefronts or picture/windows.

Figure 23. BURGLARY RESISTIVE GLASS

A fire bomb thrown into Amerada’s Secur-Lite glass dramatically demonstrates both the impact resistance and fire resistance offered by this glass. Secur-Lite glass is the first glazing material to be listed by Underwriters’ Laboratories as burglary resistant. Illustration courtesy of Amerada

Glass Company.

61

62 / How to Burglar-proof Your Home

versely, burglary resistive glass can provide the highest degree of protection offered by glazing materials and is available in several degrees of protective capability. Aesthetic requirements may, at times, tip the balance either way in those situations where more protection than that offered by ordinary glass is required.

Plastic Glazing Materials Glass substitutes, made from plastic, are currently being offered as a glazing material with the implication that burglary resistance is provided by the shatter resistance of a comparatively resilient plastic. While the shatter resistance of such material may be very high, its other characteristics may, under certain circumstances, make it less desirable than other high-strength glazing materials. First, it is not as hard as glass; therefore, it scratches more easily, especially when abrasive cleaning agents are used or when dust settles on the window and is wiped off. Second, because it is plastic, such glazing material may easily be drilled and sawed out with a keyhole saw to gain entry. This entry technique leaves clear evidence of forced entry, however, and may be adequate for insurance purposes in most instances. The question appears to be whether one would rather collect insurance or retain his possessions.

Secondary Entrances Traditionally there has been an unfortunate tendency in residential construction to provide the finest and most ornamental of hardware for the front door while neglecting entirely the protective capability of the hardware applied to the back door or

Other Considerations Regarding Doors / 63

other secondary entrances. This situation continues to occur despite the fact that simple logic indicates that the back door is the one usually burglarized. The fact that inferior hardware is being used on back doors at least partially accounts for the fact that when a burglar attacks the door of a residence, the back door is the one most frequently selected for attack. The prospective burglar can usually count on finding a lock with lesser protective capability on the back door than on the front door. Additionally, the burglar usually considers the back door a safer place to work, as it usually offers a reduced degree of visual exposure. This tendency to neglect the protective

requirements

of secondary

entrances

gives

a

twofold advantage to the burglar. The protective capabilities of the back, side, and garage doors should be at least as great as those of the front door; in fact, if a difference in protective capability is to exist, the greater protection should be assigned to the secondary entrances. Interior Doors

Interior doors are customarily equipped with a passage latch that has no locking function and serves merely to keep the door closed. Such doors are simply for convenience and furnish a degree of privacy. They also serve as a means of isolating smoke or flames in the event of a fire, although the degree of isolation provided is usually quite small and strictly temporary. Since the principal function of such doors is for convenience, they will not be discussed further here. There

interior

are

doors

some

are

situations,

equipped

however,

with locks

in which

to provide

either a measure of protection or greater privacy. Privacy locks frequently are of the bathroom type—the

64 / How to Burglar-proof Your Home

outside knob is locked by means of a turn knob or pushbutton on the inside of the door. Access from the outer, or locked, side of the door may be obtained by simply inserting a nail or similar object into a hole provided for that purpose and pressing to release the locking mechanism; other versions of this lock may require the use of some simple tool such as a screwdriver or a coin from the outside to turn a mechanism that will open the door. Since this discussion is essentially limited to the subject of burglary protection, and since this type of lock furnishes no degree of burglary protection whatsoever, further discussion in this area is unnecessary. Deadbolt

Locks on Interior Doors

In certain situations an interior door is equipped

with a lock to increase property protection. When the objective of a lock on an interior door is to protect valuables, the lock selected should be the same as would be selected for an entry door of the same type. For the highest possible degree of protection against attack, the lock should be a deadbolt, unless safety considerations in the event of fire or other forseeable emergency are considered more important in that particular situation. Strong Room or Security Closet

Now, as in years long past, many homeowners are turning to the strong room or security closet for protection of their more valuable and bulky possessions. Such a room or closet, to be effective, must resist both burglary and fire; if the materials used in

the construction of such a room are not intrinsically flame-resistant, they must be made so by such means as the application of flame-retardant treating materials to wood or combustibles, and the use of flame-

Other Considerations Regarding Doors / 65

retarding paints, finishes, and furnishings. One of the most desirable locations for a strong room would be in a corner of a dry basement where all of the walls, floor, and ceiling of the room may be of poured reinforced concrete. When equipped with a metal door (fire-rated with an appropriate Underwriters’ Laboratories label) and a metal frame with a deadbolt lock of considerable strength and burglary resistance, such a room can be a very formidable deterrent, indeed. Should a basement be unavailable or unsuitable for such a purpose, a closet or another room may be used, albeit less effectively. Again, the door and frame should be of metal, preferably of the fire-door type (insulated against fire), and the closet or room should have flame-retardant construction to the greatest extent that is compatible with its burglary resistant capabilities. The use of asbestos cement board to replace or overlay wallboard is suggested to enhance fire-protective capabilities. (It is important to avoid inhaling the dust as this material is cut.) An automatic fire extinguisher of appropriate type is desirable, as are fire-retardant chemical treatments and paints, and flameproof furnishings. Methods of enhancing the burglary resistance of walls, ceiling, and floor will be discussed in Chapter 7. “Structural Integrity.” The lock used with such a room or closet should be a mortise deadbolt of a high security type with a long throw, saw-resistant bolt and a special cylinder guard. One such lock is produced by Adams-Rite Company; if that lock is used, it may be desirable to have a separate passage latch installed in the same door, as this particular lock has only the deadbolt

operation. If latching of the door other than with the deadbolt is not essential, then a simple door pull may

66 / How to Burglar-proof Your Home

be used to open the door. If an existing door is to be remodeled for this purpose, it may be preferable to add a high security rim deadbolt for this purpose. Another lock that would be appropriate is the Jimmy-Proof Super-Guard Lock with the Medeco cylinder option, manufactured by Ideal Security Hardware Corporation.

The hinges of such a door are especially important, and the author recommends a fast riveted pin full mortise butt with security stud if the door is to open outward. If the door opens inward, the security stud may be omitted. Both door and frame should be carefully checked against those items detailed in “Other Factors A ffecting Door Security,” beginning on page 50. Deadlatch

Locks on Interior Doors

On doors where fire safety is of concern and the contents merit special protection, or where snooping

by visitors or household staff must be prevented, locks of the deadlatch function offer an attractive alternative to the deadbolt, since they may offer nearly equal protection while having a desirable quick-exit feature in the event of fire or other emergency. Restrictions on lock types for glazed interior doors are substantially the same as those for glazed entry doors, except that some of those restrictions may be modified to accord with objectives that may be less rigorous.

The Springlatch When the objective of the lock on an interior door is simply a matter of greater privacy than is afforded by the bathroom latch, and positive exclusion is not essential or sought, the usual choice is a springlatch in one of the configurations shown in Figures 24, 25,

Figure 24.

A MortTISE SPRINGLATCH

Note the absence of an auxiliary latch bolt. Not having a deadiocking mechanism, such a lock must be considered to be a privacy device, not a protective device. 67

Figure 25. A RIM SPRINGLATCH

Sometimes referred to as a night lock, the rim springlatch is the most common type of rim lock but is far less effective than other types. Note the absence of an auxiliary latch bolt. The latch bolt is retracted by the thumbturn from the inside or by key from the outside. The latch bolt may be kept in the retracted position or released by an extra turn of the thumbturn (as in the unit shown here), or controlled by a slide button on the lock case or by a stop button on the thumbturn in other versions of this unit. Slide buttons, when they are used, sometimes are

designed so they may be used to deadlock the latch bolt, but implementing this feature makes both the key and the turn knob incapable of retracting the latch bolt until the slide button is moved into the release position. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

68

Other Considerations Regarding Doors / 69

and 26. Although the rim springlatch of Figure 25 is suitable from the functional standpoint, it may be somewhat detrimental to the appearance of interior doors. Because the cylindrical springlatch of Figure 26 is widely misused in situations where a deadlatch is the appropriate choice, some manufacturers and lock wholesalers have completely discontinued selling locks in this function, as a deadlatch is always an appropriate substitute for a springlatch. The springlatch operates in exactly the same manner as the deadlatch, but it is a simpler mechanism. The springlatch, like the deadlatch, locks by immobilizing the outside knob to prevent it from being turned to draw the latch bolt into the lock. The inside knob, like that of the deadlatch, is always free. The latch bolt is not deadlocked by any mechanism whatever, nor are the pushbuttons guarded. Abscence of these features makes the springlatch much less resistant to burglary than is the deadlatch. Because it is a simpler mechanism, the springlatch is somewhat less expensive to purchase and easier to maintain in good operating condition than is the deadlatch. The springlatch is commonly used in locations where the objective is more to exclude casual snoopers than to protect, for example, an office, den, or a storage room where household supplies or equipment are kept. If aconsiderable value is represented in the stored articles and they can be sold readily, the more secure deadlatch or deadbolt function would be more appropriate, since either of them provides an extra measure of burglary protection. Types of Interior Doors The most common types of interior doors are the panel and hollow-core doors illustrated in Figures 16 and 17. Where a significant degree of burglary pro-

70 / How to Burglar-proof Your Home

Figure 26. A CYLINDRICAL SPRINGLATCH

Note the absence of a deadlocking plunger. While this lock function usually is slightly less expensive than is a corresponding deadlatch, the price differential usually is small for the added protection of the deadlatch feature. Sometimes it is possible to purchase conversion parts to convert the springlatch to a deadlatch function at substantial savings compared to the cost of replacing the entire unit.

tection is required in an interior door, the solid-core

type should be considered. Although metal doors are available for interior use, usually the wall in which such a door is set does not warrant the additional

protection of a metal door because the wall itself would be much more vulnerable than the door. If, however, an interior wall is of masonry construction or otherwise beyond the usual strength found in interior walls, it may be feasible to consider the use of a

Other Considerations Regarding Doors / 71

metal door for the protection of valuable property. (See preceding material under “Strong Room or Security Closet.”) Condition of Locks

Before concluding the subject of doors and locks, it is desirable to consider the true condition of those locks in terms of the protection actually afforded by them. Some of the conditions that affect the dependability and burglary resistance of locks are inevitably related to the quality of the lock. Although this is of great importance, it is only part of the picture. Other conditions that will affect the protection afforded by locks that are otherwise eminently satisfactory are less obvious and often are given scant, if any, consideration. They are the continuing responsibility of the homeowner and come under the broad general category of the condition of locks. Although a complete discussion of the subject would be voluminous, certain aspects will be mentioned here. The very heart of the protection offered by any lock is the individuality of the key to that lock, so let us begin by considering the key as a vital part of the lock. Integrity of Keys

A very important aspect of the degree of protection one should be able to expect from a lock has to do with the keys. If keys have been lost, or especially if keys have been stolen, then the combination of the lock should be changed so that those lost or stolen keys will no longer operate the lock. The changing of lock combinations, particularly of entry locks under

these circumstances, should be done immediately, with no delay whatsoever. It is fallacious and wish-

72

/How to Burglar-proof Your Home

ful thinking to expect that the keys may turn up later. If lost keys have fallen into unscrupulous hands, then the householder is in jeopardy until those locks are changed. Keys that the householder believes to have been stolen present an extreme danger, and special protection should be given to the premises immediately and continued until the combinations of the affected locks have been changed. Keys that have been lost and returned likewise present a danger because someone who found them, whether or not it was the person who returned them, could have had them duplicated while they were out of the householder’s control. In choosing the person to change the affected lock combinations, it is highly advisable to select a locksmith of high reputation and standing in the community in order to avoid the risk of giving an unscrupulous person access to the combination for your locks. The only assurance the householder has that he possesses the only keys to a lock is the integrity of the person who is changing the combination of the lock. Wear

Wear is another factor that can adversely affect the protection supplied by any lock, even the finest. Wear, as it affects the protection afforded by a given lock, is usually manifest first in the lock cylinder itself, whether of the pin tumbler type or one of the less expensive disc tumbler types. When locks become sufficiently worn, the tolerances to which the manufacturer built them are seriously upset and are usually in a state of imbalance. This disruption of the normal tolerances in a lock causes the lock to lose much of its pick resistance. The wear in a lock cylinder is in large part the result of the simple act of inserting and withdrawing the key as the lock is used. It is often manifest by the key’s “jumping” as

Other Considerations Regarding Doors / 73

the initial move is made to turn it in the lock. After the initial jump has taken place, the key will usually turn quite freely for the rest of its rotation. The same phenomenon may result from poorly cut duplicate keys, and use of such a key will seriously accelerate the wear in the lock cylinder. Wear in a lock cylinder due to a worn or faulty key takes place very rapidly to the point where the protection it furnishes becomes seriously reduced. For this reason, it is suggested that all keys be made by the most reputable locksmith available in order to assure their accuracy

and the consequent increased durability of the lock. This kind of wear may be detected in several ways, of which the jumpy key is but one. Another clue that wear has taken place may be indicated when a new, or nearly new, key enters the keyway very loosely. This usually indicates that the keyhole itself is worn, and when this is the case, the internal parts are almost invariably worn to a corresponding degree, thus largely negating the protection of the lock cylinder. A worn lock may sometimes be detected by shining a bright light directly into the keyway and looking in to determine whether the tumblers show wear to the extent that pin tumblers become chiselshaped, rather than conical on the point.* (See Figure 27.) If the lock is a disc tumbler lock, the chances are that it furnishes

poor protection

in the first place

when compared to pin tumbler locks and is barely adequate for any usage in modern protective measures, even though in the best of condition. Wear of a corresponding type shows up in a disc tumbler lock in the form of a sharp edge on the tumbler where it *An exception is the MEDECO lock cylinder, a high quality lock cylinder using pin tumblers which are chisel-pointed when new. A small initial “jump” is also normal in turning the MEDECO key.

Figure 27. COMPARISON OF NEW AND WORN PIN TUMBLER CYLINDERS

The cylinder at the left is new. Note that the configuration of the keyway is sharp and clear. Tumbler points (not visible in this photo) are conical. In the worn cylinder at the right, the configuration of the keyway is worn and indistinct. Tumbler points (not visible in this photo) are worn to a chisel shape. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

74

Other Considerations Regarding Doors / 75

meets the key, or as a shallow groove in the flat surface of the tumbler with the top part of that groove showing considerable indications of wear. (See Fig-

ure 28.) This groove should not be confused with a shallow groove that may have been built into the tumbler by the manufacturer (this tumbler configuration is used in masterkeying disc tumbler locks).

There are disc tumbler locks that supply excellent protection, but their use is not widespread, and it is recommended that a disc tumbler lock be replaced with a pin tumbler lock of good quality, unless, of course, the disc tumbler lock in use can be verified as being one of those types that offer excellent protection. In summary, then, the three methods by which wear to the detriment of the physical protection furnished by the lock cylinder may be detected are: (1) jumpy operation of the key, (2) a badly worn keyhole, and (3) chisel-shaped tumblers.

Dirty and Sticking Locks Dirty and sticking locks, while usually considered a minor annoyance, may seriously affect the protection furnished by an otherwise perfectly adequate lock. When locks become obviously dirty, or when the return action of the knob or latch bolt is sluggish, or resistance to turning the key is excessive—then it is time to have the lock cleaned and relubricated. This will prevent the sticking of some vital part that can cause the lock to appear to lock the door and yet fail sufficiently in one of its vital functions that it actually provides only the illusion of protection. To avoid this situation, all locks, of whatever type, should be kept in reasonably clean and smoothly operating condition. All the locks in a household should be checked at regular intervals, say two or three times a year, for erratic operation, whether those abnormalities in operation are caused

76 / How to Burglar-proof Your Home

Figure 28. NEw AND Worn Disc TUMBLERS The solid lines superimposed on the disc tumblers above show the portion of those tumblers that is visible through the keyhole. A new tumbler is at the center. The worn tumbler at the left presents a considerably different appearance when viewed through the keyhole but should not be confused with the “stepped” tumbler at the right (also new), which is used in masterkeying this type of lock.

by dirt and sticking, by worn parts, or by deliberate tampering by a potential burglar. Erratic operation that may affect the protective capacity of a lock may manifest itself in something as seemingly innocuous as a roughness or uneven turning of the knob, in failure of the latch bolt to protrude properly, or in the failure of the auxiliary latch of a deadlatch to depress far enough to activate the internal deadlocking mechanism of the lock. The last of these conditions may exist because of a worn auxiliary latch bolt or because of an excessive gap between door and frame.

Other Considerations Regarding Doors / 77

Worn parts may occur in the deadlocking mechanism inside either the deadbolt or deadlatch lock, causing it to lose reliability. A few simple tests to uncover the more common defects in locks of the various functions are illustrated in Figures 29 through 31. The deadlatch is ordinarily quite an effective type of locking mechanism, but it has certain vulnerabilities that do not appear in the deadbolt. One of the most important of these is the possibility that the strike could be stuffed by a potential burglar. In this particular technique, the latch bolt pocket of the strike is stuffed partway full of paper or some other foreign object to keep the latch bolt from extending fully into its pocket in the strike. This bypasses the deadlatching mechanism and makes the latch bolt vulnerable to shimming in the same manner that a springlatch is vulnerable to that operation. If a stuffed strike should be detected by the householder after a visit by strangers,

salesmen,

or suspicious

persons, the householder should quietly remove the stuffing material after calling the police department. In all probability police can capture a burglar by watching the premises during the next few hours or days. Since the days of Watergate, everyone knows about the vulnerability of the deadlatch to the technique of taping the latch bolt back. It is both an obvious technique and a stupid one. No more need be said. A related problem in the deadlatching mechanism occurs when well-meaning but unknowledgeable workmen install this type of lock without cleaning out the strike pocket so that no wood touches the latch bolt. Sometimes carpenters will leave a tapered surface on the wood behind the strike plate for the

Figure 29. TESTING THE SPRINGLATCH

Failure of the unit to pass any of these tests indicates that the unit requires prompt attention. 1. If the springlatch is of a type that functions by immobilizing one of the doorknobs when it is locked, the operation of the inside knob must be independent of the functioning of the outside knob. To test this independence, begin with both knobs unlocked and, grasping both knobs, simultaneously turn them in opposite directions. When the knobs have reached their limit of travel, release them at that point. Do both knobs

return freely and fully? Does the latch extend itself to the maximum extension of which it is capable? A negative answer to any of these questions means the lock requires prompt attention. 2. Holding the latch bolt in the retracted position as shown, gently turn each knob to its maximum rotation. When it has attained that position, release it gently to determine whether the knobs return fully to the neutral position as they should. A bit of tape or a crayon mark will sometimes help in determining whether or not the 78

Other Considerations Regarding Doors / 79 knobs are returning fully. In this particular test, the knobs must be tested individually, Not simultaneously,

and in only one direction at each test. 3. In testing the latch bolt return, both knobs must be in the neutral position. The latch bolt is depressed into the fully retracted position and released very gently. The latch bolt should extend itself fully, smoothly, and automatically. Repeat the test, releasing the latch bolt very quickly, observing it for quick, smooth reextension. 4. For this test, the outside knob is locked and an attempt is made to rotate the locked knob by hand,

applying a moderate amount of force. The knob should be firm and free of give in both directions. Turn the inside knob to the limit and release it at that point. Repeat, turning the knob in the opposite direction. The knob should return fully and the latch bolt should extend fully, smoothly, and automatically.

latch bolt to come up against, so the door will fit snugly. Such workmanship will appear to be better than it actually is, unless this situation is specifically sought out. Under no circumstances should the latch bolt touch any wood behind the strike plate, whether on the flat surface of the latch or on the end of the latch, because this situation may cause the latch bolt to fail to extend far enough for the deadlocking mechanism to engage it, even though the lock itself is in otherwise perfect condition. Another common installation problem is that workmen who do not understand locks, or who don’t care, sometimes install locks upside down in the door. A door lock should always be installed so that the cut (notched) edge of the key enters the lock cylinder in the upward position. Several rather nasty consequences are possible as a result of this particular form of incompetence: The deadlocking mechanism of many mortise deadlatches will not engage to secure the latch bolt properly. Some deadbolts will

Go CC

SI

Figure 30. TESTING THE DEADLATCH Since the deadlatch is similar to the corresponding springlatch, it is tested in exactly the same manner. Additional tests, however, are required for the deadlocking mechanism. For these tests, the lock is

preset in the locked position. The auxiliary latch or plunger is depressed, not completely (as in this illustration), but to a point slightly less than that to which the lock’s strike plate moves it. End pressure is then applied firmly to the latch bolt. The latch bolt should come to a firm stop in a position that, if the door were closed, would leave it firmly engaged in the strike pocket. With the auxiliary latch bolt free, the latch bolt is

pushed fully iato the lock; then the auxiliary latch is partially depressed as before, and that position is maintained while the latch bolt is slowly permitted to extend itself. After the latch bolt has extended as fully as it will, an end pressure is applied to it, maintaining all the while the partly depressed position of the auxiliary latch bolt (or plunger). The deadlocking mechanism should engage the latch bolt firmly when this is done. Illustration courtesy of Eaton Corporation, Lock and Hardware Division.

81

Figure 31. TESTING THE DEADBOLT

Maintaining a light end pressure on the deadbolt as shown, the bolt is extended by use of the key in the outside lock cylinder. Operation of the key is continued and the key removed, just as it would be in locking the door from the outside, including the removal of the key from the lock cylinder. End pressure is maintained continuously throughout this entire operation. If the bolt remains extended after the key is removed, the lock is

providing all the protection it was designed to furnish. The test is then repeated, using the inside cylinder or turn knob to extend the bolt. The bolt must remain extended at the conclusion of this test, and it is as

important as the first test. 82

Other Considerations Regarding Doors / 83

fail to deadlock the bolt after a single internal spring gets a bit weak. The key will fail to operate just about

any lock after one of the tumbler springs gets weak, because it gets hindrance instead of help from gravity; it would get help from gravity if the lock were properly installed. Dust or dirt blowing into the keyhole is much more likely to lodge in the tumbler chambers of pin tumbler locks, causing the tumblers to jam so the key will not operate. There are other possible consequences, but space precludes going into them.

D Windows

A common point of entry is through a window. There are several ways to enter through windows, depending to a considerable degree on the type of window, its size and location, and the amount of dis-

turbance that is required to gain entry in terms of noise level or duration. One aspect of entry through a window is the size of the panes of glass and the size of the opening available after the glass is broken or removed. The window that has small panes and is securely locked is going to require that the window be unlocked and the sash moved out of the way, or the dividing pieces that segment the window into small panes are going to have to be removed, a process accomplished either by force or by cutting them. A small windowpane with sturdy dividers between the individual panes forms a reasonably good deterrent to entry if the window is locked in such a way 85

86 / How to Burglar-proof Your Home

Figure 32. COMMON

SASH LOCK

that the burglar cannot break out one small pane of glass and reach through the hole to unlock the sash. Use of the common types of sash lock (Figure 32) found on most wooden window frames just about precludes effective burglary protection for the window when the glass-breaking technique is used. A window divided into small panes with good, sturdy dividers equipped with a lock that requires a key to unlock the sash will furnish a more realistic degree of protection against burglary. A lock of this type is shown in Figure 33. If the dividers are flimsy or if the locking arrangement on that window does not

include a firmly anchored, key-operated lock, the protection is none too reliable, at best. In a window with small panes, a metal sash will usually provide a significantly greater degree of protection against bur-

glary than will a corresponding wooden sash. Here again, the criterion is that the locking arrangements

Windows / 87

be such as to preclude its operation by merely reaching through a broken pane in the sash. Locations of Windows

Another aspect of window entry that is all too often overlooked is the placement of a window too near a door that requires only the operation of a knob or thumbturn to unlock from the inside. If a window

a

LOGD

Figure 33. KEY-OPERATED SASH LOCKS To be effective, the key must be removed from the

range of all possible fishing techniques after the window is locked. A drawer is a good place to keep such keys. A word of caution: For the sake of convenience, many lock manufacturers key all or a large part of their production of key-operated sash locks to the same combination. To avoid the hazards associated with this possibility, it may be advisable to have your locksmith rekey sash locks to a key that is more nearly yours alone.

88 / How to Burglar-proof Your Home

is close enough to an entry door to permit a burglar to reach through a broken pane of glass to unlock a door, either by hand or by use of a simple manipulating instrument,

that door should be treated in the

same manner as a door with glass in terms of protective measures.

Window Locks and Locking Methods

The common sash lock shown in Figure 32, used on a wooden window sash, is only as effective as the glass in deterring burglary, because once the glass is broken or penetrated, a burglar can reach inside and manipulate any sash lock to the unlocked position, unless it is key-operated. Some key locks made for windows are shown in Figure 33. These types are representative of what should be used when windows are protected by no other means than common glass in the sash, or when manipulating instruments, however small, can be inserted between the upper and lower sash.

Regarding the protective capability of the glass, a factor to be considered is that the glass should not be removable from the outside of the building. The sash should be solid over the glass when viewed from

the outside of the protected premises. Glass held in place merely by putty and glazier’s points on the outside can become loose or be removed. It is quite vulnerable, and it is not unknown for a burglar to take advantage of this situation. For this reason, the window sash should be carefully chosen so the glass is removable only from the inside, or some other means

should be considered for protecting the window. A few types of wood and metal sashes are provided with an interlocking tongue and groove construction that, when the window is closed, effec-

Windows / 89

tively locks the panes of the window together to secure them against prying that would separate them from one another. If a reasonably good manually operated deadbolt device is provided on these windows, and if the glass is of the wire glass or burglary resistive type and is not removable from outside, a window can offer a reasonably good burglary resistance. Here again, the lock is no more secure and provides no more resistance to burglary than does the glass with which that window is equipped. Even though a window may be equipped with a very positive deadlocking device, some additional protection should be considered for windows where mere breaking of the glass will give access to a manually operated lock, either on the window or on an adjoining door. This is particularly true when such a window is in a vulnerable location that offers convenience and protection to a potential burglar. Storm Windows

and Screens, Bars and Grilles

As a general rule, storm windows and screens provide little or no protection, because screens can be cut and storm windows broken or removed easily. One of the alternative measures for window protection is the installation

of grilles, bars, or shutters.

These will impede the entry of a burglar even though the window glass is broken. Attractive ornamental window grilles are available and are especially desirable on windows in vulnerable locations—where lighting may be poor at night or where the breaking of glass would not create sufficient disturbance to arouse neighbors or occupants of the house. Bars and shutters likewise can be made both attractive and effective as a burglary deterrent. The criterion for use of any of these as a successful burglary deterrent is

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that they must be sufficiently strong to create an appreciable delay or require the making of considerable noise in physically ripping them out. Another factor in the use of grilles, bars, and shutters is that they must not readily be removable from outside. This requirement can be met in several

ways. The screws or bolts by which they are attached to the structure can be deliberately damaged in such a way as to render them extremely difficult to remove. Nuts may be welded on after installation or ends of bolts can be riveted over the nut if through bolts are used. If this technique is used with studs, then those studs must be kept from rotating in the mounting bracket, possibly by using a pin, key, or screw under the nut in such a way as to be protected from access by the presence of the nut. If the protective device is attached with screws, one-way (or streetcar) screws may be used; these screws may be driven in quite readily, but the slot in the screw is made in such a way that in any attempt to remove that screw the screwdriver would slip out of the slot and the screw would remain tightly in place. If this type of screw is not available, then a common screw or bolt may be drivenin,in the customary manner and the slot or head of the screw battered until it is unusable. The screws, of course, should be sturdy enough to hold the device firmly in place. If necessary, lag screws (lag bolts) should be used and the heads welded to the grille to prevent their removal. Securing Window Frames Occasionally, burglars may attack a dwelling by removing the entire window frame—glass, sash, and all. Wooden window frames are particularly vulnerable to this technique because many of them have an

Windows / 91

outside casing that is attached only by nails. Or they may have been glued on at one time, and the glue may have deteriorated, leaving only nails holding the outside casing to the frame. When this condition exists, it is fairly simple to pry off the outside trim of the window, push the window frame right into the house, and enter through the resulting hole. Such entries sometimes are done in broad daylight by burglars pretending to be ordinary workmen doing repairs or

building alterations. This particular technique may be guarded against by the rather simple expedient of inserting flat-headed (countersink) wood screws of considerable strength through a hole drilled in the channel in which the window sash runs, in such a manner as to anchor the frame firmly to the adjoining wall stud. These screws should be covered by the window

sash when

the window

is closed, as illus-

trated in Figure 34. The heads of the screws should be countersunk slightly below the surface of the window frame to avoid interfering with the free operation of the sash. While doing this job, it is important to remember the presence of counterweights or spring balances behind the frame, between it and the nearby stud, and position the screws in such a way as to avoid any interference with the counterbalancing action of these units. Otherwise, the maintenance problem is likely to be quite severe. Again, it is important that these screws be inaccessible from the outside when the sash is closed. Sometimes wooden window frames have a metal flange attached to the frame; this metal flange protrudes behind the siding of the house and is attached to the house under the siding. It is nailed in place on both sides of the flange. This construction furnishes substantially greater protection than do frames that are not so equipped, but after the structure is com-

Outside Casing

Outside Sash Channel

Stop

Inside (Blind) Stop

Inside Sash Channel

Figure 34. SECURING A WINDOW FRAME

Two or three screws on each side of the frame vertically close to the center of the sash should be sufficient to guard against removal if the screws are of adequate strength. Note: If counterweights are used to

balance the sash, it may be necessary to replace them with appropriate spring balances to keep the new screws from interfering with the operation of the sash. 92

Windows / 93

pleted, it is very difficult to determine whether this type of construction has been used. Because of the difficulty in making this determination, it is recommended that screws be used in the fashion described above unless there is positive knowledge of the existence of such a flange. Metal Window

Frames

Metal window frames usually offer better protection against removal from the outside than do wooden frames, because they have an integral flange on the frame that projects over a wall stud to which it is attached with nails or screws. This arrangement makes the removal of the entire frame difficult and usually impractical as a means of entry. Metal frames are usually made for convenience in removing the sash for cleaning and like purposes. The very ease of removal, however, is all too often an easy means of access to an intruder, unless the window has been designed in such a way that the glass positively is not removable from the outside by prying or other such means when the window is closed and locked. Some windows may present only the appearance of this type of construction. One thing to watch for on a metal sash is to see that, at the point where the panes of glass join together, the sash has an overlapping and interlocking tongue and groove arrangement to make both sashes into what amounts to a single unit while the window is in the closed position. The locking mechanism on many metal sashes is quite inadequate. It should provide a positive meeting of the locking surfaces, not only while they are new, but when they are in a condition of advanced wear as well. The effect of advanced wear should be

94 / How to Burglar-proof Your Home

estimated as carefully as possible and the selection of windows governed accordingly whenever new windows are to be purchased. A deadlocking arrangement by means of a hook lock, similar to that shown in Figure 35, is good, except that it is vulnerable once the glass has been broken. (For burglary insurance, this is often sufficient.) If it is possible for a burglar to reach through a hole broken or cut in the glass to unlock the window, a key-operated lock should be considered unless the panes are so large that a burglar could crawl through one if it were broken out.

Figure 35. Hook Lock Devices FOR METAL WINDOW FRAMES

The hook lock arrangement shown here utilizes square edges latching together over a reasonable length of meeting surface. A matching square edge is provided on the frames to lock the sash to the frame. An interlocking channel is provided to lock the movable sash and the stationary sash together to keep them from being sprung apart when the window is closed and locked. The movable sash will not lift out when the window is closed and locked. Illustration prepared by the author with the cooperation of Beacon Metals, Inc.

Windows / 95

Some metal frames and sashes are designed so poorly that a movable sash can be manipulated in such a way as to allow it to be removed from the frame, even though the window may be closed and locked. This condition should be checked out very carefully. If necessary, the entire window and frame should be replaced with a more suitable one, unless there is a practical means of correcting the deficiencies that permit such malfunctions. Sometimes the addition of an appropriate key lock will correct the problem. Frequently it may be corrected by the installation in the upper channel, near the stationary sash, of a screw or a strip of metal or plastic to prevent the movable sash from being lifted to any degree whatever when it is in the closed position. Preferably, such a screw or strip of material should permit the sash to be removed when it is fully open. Special Glass

Where windows are vulnerable to breaking the glass, an alternative that might be considered is the use of a special glass. In some instances, a newly developed shatter-resistant plastic glazing material might be appropriate, as long as one bears in mind that it can be cut and that it may scratch more readily in cleaning than will true glass. In other cases, wire glass would be both appropriate and effective (see Figure 10). Wire glass in one of the more decora-

tive patterns can actually improve the appearance of many windows. If greater protection is required or if wire glass is

deemed inappropriate, one could consider going to a burglary resistive glass such as Secur-Lite (Figure 23), which is rated by Underwriters’ Laboratories for

burglary resistance. This glass poses some problem

96 / How to Burglar-proof Your Home

in that its thickness is greater than that of ordinary plate glass. Some window frames, particularly those used in residential construction, may not accept that thickness. In installing this type of glass, it is frequently necessary to change the entire window and frame in order to accommodate it. This radical procedure usually is not necessary when wire glass is used, making this aspect of wire glass rather more attractive. Wire glass is, however, more easily penetrated to permit the insertion of tools to operate a window latch or lock—even though making a hole large enough to reach a hand through and manually operate a sash lock could be quite difficult and rather time-consuming. For this reason, a key-operated locking device would be very much in order to derive the maximum protection from windows equipped with wire glass. Balancing Effectiveness of Deterrent Measures Since the consumption of time in gaining entry is a primary

objective

of many

protective

measures

such as special glass, locks, and so forth, it would be both futile and foolish to undertake measures that were not in balance. Only if balanced protective measures are used can the intruder be forced to call attention to himself to a significant degree by the commotion he must make and/or by the time it takes him to gain entry. These factors increase his risk of being caught, and often they are enough to deter him from making the attempt in the first place. No structure can be made entirely burglarproof if the burglar is given sufficient time and freedom of activity to accomplish entry. It is only the excessive risk of being caught that deters burglars from attacking cer-

Windows / 97

tain otherwise desirable targets. This is no less true in dwellings than it is in jewelry stores, banks, or any other historical object of burglary. In homes, just as in other buildings, the cost and practicability of the deterrent and its effectiveness must be gauged in terms of the desirability of the objective to the burglar. If special glass is to be used in any given window or windows, the results must be commensurate with the cost of the deterrent measures in relation to the value of the property they are to protect. An influential factor in that judgment should often be the burglary experience in a particular locality and the type of property that is most often a target. Basement

Windows

Special attention should be given to basement windows to ensure that they cannot be removed from the outside. The panes of glass should be too small for a burglar to get through if he should break them out, and the strength of sash dividers must be adequate. A positive locking arrangement should also be provided to ensure that the window cannot be opened once the glass is broken. This may take the form of a key-operated lock (such as a sash lock) or a padlock and safety hasp (that is, a hasp that covers its own attaching screws when it is closed). Basement windows have long been a favorite means of entry for burglars, and, like other accessible windows, they should not be visually obscured from the street or the neighbors. A burglar who finds a basement window obscured by shrubbery or other growth, a fence, or another obstruction is much less likely to be caught than if visual access is unrestricted. Planting shrubs or other ornamental growth or building fences in

98 / How to Burglar-proof Your Home

front of a basement window amounts to providing a private workshop in which a burglar may work unmolested for as long as it takes him to gain entry. Window

Air Conditioners

and Fans

A common invitation to burglary is the presence of a window air conditioner or fan in an accessible window of a dwelling. All too often, these air conditioners and fans are removable from the outside, sometimes by merely raising the window a bit and sliding some extension vanes out of the sash channel in the window frame. The air conditioner may be of a type that can be lifted to the outside of the dwelling, or it may be of a type that can be pushed on through to the inside. In either case, the access furnished to a would-be burglar is unrestricted once this is accomplished. If this situation exists, it should be corrected immediately, either by removal of the unit and the substitution of a more appropriate one, or by modification of the existing unit to the point where considerable effort and tools are required to remove it. Because of the wide variety of window air conditioners and fans, and the corresponding variety in their installation, no specific recommendations are given here, except that the householder should contact the manvufacturer’s representative for that unit and have this work done professionally. The possibility of doing the mechanism of an air conditioner irreparable damage by drilling holes in the wrong locations or by damaging or interfering with important mechanical functions of the unit is best avoided by having any work done by an expert. Fans are somewhat less critical and can often be modified by the householder without fear of doing damage. Not only should the attachment of the frame

Windows / 99

of the fan be examined carefully to determine whether the entire fan could be removed from a window, but examination should also be made of the rest of the fan to determine whether the removal of the fan blade or the motor and blades could permit access to the dwelling. If any such deficiencies are found, they should be corrected. One such means of correction could be a grille over the window. Another type of fan might require merely that the householder damage the slots of the mounting screws in an appropriate manner. Whatever is done by way of correcting the secu-

rity deficiencies of a fan or air conditioner, it would be a good idea to have a competent locksmith check the unit and its installation to determine whether all trouble points have been adequately corrected. He is an expert on the means of entry into locked premises, and in most communities his advice is more likely to be sound than that of any other person.

6 Other Openings Other openings can be found in the walls of a structure by professional burglars, but because they are not commonly used for normal entry, they are rarely considered as a possible hazard. These openings are more often overlooked by “experts” than by burglars. Any opening, however innocuous, or whatever its intended purpose, should be examined carefully to determine its possibilities as a means of illegal entry. Some of those other openings will be discussed here, but they by no means exhaust the possibilities. They are merely the most common of the overlooked openings that burglars do dearly love to find.

Attic Ventilators An

attic ventilator

is a common

feature in most

houses and all too often presents little if any resis101

102 / How to Burglar-proof Your Home

tance to forced entry. Sometimes ventilators are mere flimsy slats of wood; at other times, they are metal louvers applied with nails or screws from outside. If either of these situations exists, a remedial measure should be taken to render that area as structurally strong as the wall of the house itself, or, depending on the design of the building, the landscaping, and the positioning of the structure, at least as strong as similarly located windows above the ground floor. Ventilators in the eaves of a roof far above ground present less of a hazard than do ventilators that open up onto a lower level such as a porch roof or those that are more readily accessible from ground level. If a long ladder is required to reach the attic ventilators, the risk of the ventilators being penetrated is considerably reduced. If the louvers are removable from the outside simply by removing screws or nails, then some type of internal fastening for them is in order. One simple and effective way of securing louvers from the inside is by means of metal brackets applied to the studding of the house and to the louver itself, using sturdy screws to make the attachment. Those screws should be firmly set and should not penetrate through the louver to the outside. It is important that the screws be installed with a screwdriver and not be driven in with a hammer, as sloppy workmen are prone to do. If the louvers are flimsy and could be knocked out or sawed readily, then metal bars, a grille, or heavy mesh wire such as cyclone fencing may be installed inside the attic to cover the louver. If the louver can be penetrated enough to insert tools to ~ attack the attaching screws that hold it in place, those screws should be damaged deliberately to make them as difficult to remove as possible.

Other Openings / 103 Exhaust Fans

An attic ventilator may include an exhaust fan mounted inside it. Precautions should be taken so that such a fan cannot be dismantled or removed from the outside. Again, this is especially important if such ventilating devices are too readily accessible from either the ground or a porch roof. A louver or an exhaust fan in such a location is just as important a consideration in the adequate protection of the building as is a window in a similar location. Roof Hatches

Roof hatches are relatively rare in private dwellings, but they exist sufficiently often that the roof area should be checked carefully to determine if such a hatch does exist. Such roof hatches are quite common in apartment buildings, hotels, and condo-

miniums. Wherever a roof hatch is found, it must be carefully secured. Whenever possible, the roof hatch should be locked in place from the inside. Sturdy bolts or bars on the inside are a very effective means of securing roof hatches—if they are positive in their operation and cannot be manipulated from the outside or through a small opening. If it is necessary to lock a roof hatch from the outside, the recommended method would be by means of a good quality padlock with a sturdy safety hasp. If the hatch is not hinged, or if the hinges are not sturdy or are vulnerable, two such padlock and hasp combinations may be required to lock the hatch effectively. Diligent care should be given to the locking of roof hatches, because they are a favored point of entry by burglars. Where ladders or fire escapes are connected to the building, or where ladders are readily available,

104 / How to Burglar-proof Your Home

the vulnerability of roof hatches is considerably greater, and protective measures should be even more diligently applied. Central Air Conditioners

Air conditioners are found in two common types—the window type and the central, or built-in, type that operates through the heating and ventilating system of the building. As discussed earlier, window air conditioners are all too often easily removed from the outside and present a serious hazard of burglary. All air conditioners require outside air to dissipate the heat generated in the compression coils to enable the unit to provide a subsequent cooling action. In addition, some air conditioners require the intake of outside air for circulation in the building. Central air conditioning frequently requires a sizable air intake hole in the wall or foundation of the building. Ductwork then leads air to and from the air conditioner. Such ductwork commonly is a rather light gauge of sheet metal and at times incorporates such conveniences as inspection ports and crawlways for servicing purposes. For these reasons, the intake opening for such a unit should be well protected with grillwork that cannot be removed from the outside. Even though the intake or exhaust aperture may lead directly only into the inside of the duct that carries the air to or from the air conditioner, ductwork is commonly insubstantial and provides little or no effective resistance to intruders. Since not all burglars are big and burly, any opening capable of providing entry, even for a small child, should be grilled just as effectively as a much larger opening. If a central air conditioner is also

Other Openings / 105

equipped with a separate warm air exhaust this, too, should be grilled carefully.

duct,

Air Intake Fans

Fans that bring outside air into the house may be found in windows, in attic louvers, or in openings in the wall, foundation, or basement of the building. Such fan openings should be carefully protected with grillwork, bars, or grates in such a way that the protective device cannot be removed from the outside. The fans themselves provide a very low degree of resistance to burglary, even when they are not the type that merely slide into a window. If the structure of the fan prohibits its removal from the outside, and if the metalwork and framework of the fan are sufficiently heavy to impede any entry through the opening occupied by the fan, then further protection is not necessary to cope with ordinary burglary situations. This is particularly true in attic locations. Because fans with an adequate degree of resistance are quite rare, a critical inspection should be made to determine whether grillwork or protective gratings are justified. Foundation Vents and Crawl Entries

Even though foundation vents and crawl entries

may not give direct access to the interior of a dwelling, they do give access to a place where an intruder may work unobserved to gain access to the interior. Any condition of that type automatically poses a severe hazard of burglary and requires immediate correction.

Foundation vents are apertures commonly found in the foundation of a building without a basement.

106 / How to Burglar-proof Your Home

They allow air to circulate to prevent deterioration of the structure by accumulated moisture or excessively dry trapped air. Such openings may be located in the exposed part of the foundation, or they may be located under a porch. Diligent examination should be made to locate all such openings, and if they are found to be large enough for a small person to enter, they should be effectively barred or grilled or equipped with protective devices that cannot be removed from the outside. Preferably such protective devices should be imbedded in the masonry of the structure itself. If the structure does not have such protection, then a protective device may be bolted into the masonry by the use of expansion shields or other suitable means of anchoring bolts to masonry. Once the device is bolted into place, the bolts should be completely out of reach of any tool that might be capable of removing such a bolt from the outside, including a flexible extension socket wrench. If, due to the nature of the protective device used, it is impossible to secure adequate protection for the heads of the bolts to prevent their extraction from the outside, the bolt should be welded in place after installation. In addition to providing resistance to intruders, foundation vents should also be equipped with mesh that has holes sufficiently small to exclude small animals and rodents from the area under the floor. Even though foundation vents can be so small that they are of little or no interest to potential burglars, crawl entries are an entirely different matter. These are openings provided in the foundation of a building for the purpose of admitting personnel when work is required on plumbing, heating, or electrical facilities. Crawl entries exist in nearly every structure that has a foundation but no basement. Fre-

Other Openings / 107

quently, crawl entries are located under a porch or in some inconspicuous place around the perimeter of the foundation. Since they are intended for personnel entry, they are sufficiently large to be of significance in regard to burglary. A coal bin should be considered as a crawl entry for the purposes of this discussion. It is nearly always large enough for a person to enter.

Any such entry should have a sturdy door with strong riveted pin hinges firmly attached. Those hinges must be of the full mortise type in order to avoid attack by removal

of their attaching screws.

Crawl entry doors must be provided with a very secure method of locking. Customarily, the method used is a padlock and hasp arrangement, and all too frequently, those provided are too flimsy to be of any real value for this type of use. If a padlock and hasp must be used for locking a crawl entry, please refer to the section on padlocks and hasps later in this chapter. Wherever practicable, a preferred alternative to the padlock and hasp arrangement would be a lock such as the jimmy-proof rim deadlock or a rim dead-

bolt; either should be of the best quality. In multiple-story structures such as apartment houses, hotels, apartment hotels, condominiums, and

the like, crawl entries are usually provided for access to the space between the ceiling of one level and the floor of the level directly above. Some entries provide utility access on every other floor, serving two levels with a single entry, but some buildings provide such an access on each level. These entries are just as important as are corresponding entries in a foundation. They, too, may provide access to the

floor or ceiling of a dwelling unit, whether that access

is by the legitimate serviceman or by an unlawful intruder. Many people may ask, “Why all this preoccupa-

108 / How to Burglar-proof Your Home

tion with crawl entries when they do not give access to the interior of the dwelling, but only to the floor or ceiling?” All too often, people come home to find a gaping hole in the floor or ceiling of their dwelling and the contents of the premises thoroughly ransacked. Once an intruder gets through the door of a crawl entry, he is either totally or relatively unobserved and has plenty of time in which to make or find a hole large enough for entry to the interior. Once

such entry has been obtained, a door can be opened from the inside (unless double cylinder locks are used); even such bulky items as furniture and major appliances can then be removed with relative ease.

Utility Entrances There is a growing tendency toward underground installation of utilities in residences, apartments, and public buildings. Although this type of installation

is attractive

aesthetically

and desirable

from the standpoint of exposure to the elements and in other ways, it is important to be certain that the point of entry to underground utilities is not through a tunnel or crawlway that may be accessible from the outside. If such an opening exists, it should be effectively barred from the inside, just as any other type of opening would be. Even when utilities are located above ground, they may be installed in two-way openings—that is, one door opens to the outside of the building and another door opens to the inside of the building. When this situation exists, it is essential that at least the inside door, if not both, be effectively locked against both personal ingress and manipulating devices that may be inserted to unlock a favorably positioned door or window.

Other Openings / 109

Hasps and Padlocks Padlocks and hasps are produced in enormous quantities and in a wide range of types and qualities. The padlock and hasp, one of the most versatile locking methods ever devised, is extensively used. However, this locking arrangement has certain inherent vulnerabilities not found in other locks. The entire mechanism, hasp and padlock alike, are exposed and vulnerable to attack. Because of this peculiar vulnerability, the padlock is usually one of the poorest choices with which to lock something, especially if it might be capable of accepting another type of lock. In the hasp and padlock combination, the padlock is no stronger, and no better, and furnishes no more protection than does the hasp, and vice versa. In this respect, let us examine the hasp in some detail before proceeding to the padlock. Hasps

Hasps are available in a wide variety of shapes, designs, and materials to suit various purposes. This variety almost automatically presupposes an equally wide range of reliability, and that is exactly the situation. The great majority of all the hasps sold and used today are of two general types, so our discussion of the topic will be confined to those two broad classifications. Hinge Hasps. When the purpose of a hasp and padlock combination is to thwart burglary, the hinge hasp, illustrated in Figure 36, with exposed screws that can be removed readily—even with the padlock in position—is almost useless. The fact that these screws are so accessible entirely defeats the burglary protection of such a hasp. The sole exception is when the hasp is applied with bolts that go com-

110 / How to Burglar-proof Your Home