Door security

Door security relates to prevention of door-related burglaries. Such break-ins take place in various forms, and in a number of locations; ranging from front, back and side doors to garage doors.

Common residential door types
The following are the types of doors typically used in residential applications: solid wood door, panel doors (hollow and solid core), metal skinned wood-edged doors and metal edge-wrapped doors. Typically, door frames are solid wood. Residential doors also frequently contain wood.

Security weakness of common residential door types
Security tests by Consumer Reports Magazine in the 1990s found that many residential doors fail or delaminate when force is applied to them. Solid wood doors withstood more force than the very common metal skinned wood-edged doors used in newer construction. A broad range door manufacturer, Premdor (now Masonite) once stated in one of its 1990s brochures entitled "Premdor Entry Systems" page 6 that "The results of tests were overwhelming, Steel edged doors outperform wood-edged doors by a ratio of 7 to 1  When you consider the practically two-thirds of all illegal entries were made through doors... One hit of 100 lb [ lbf ] strike force broke the wood-edged stile and opened the door.  To actually open the steel-edged door required 7 strikes of 100 lb pressure [force]." Most door manufactures offer a number of different types of doors with varying levels of strength.

Consumer Reports Magazine also reported in its test results that door frames often split with little force applied and lower quality deadbolts simply failed when force was applied to the door.

The Chula Vista Residential Burglary Reduction Project which studied over 1,000 incidents; "We also learned what prevention techniques seemed to have little effect on whether a burglary would be successful. Methods found to have relatively low effectiveness included: sliding glass door braces, such as wooden dowels, as opposed to sliding door channel or pin locks; deadbolts installed in the front door only; and outdoor lights on dusk-to-dawn timers"

Burglary tactics
The Chula Vista Residential Burglary-Reduction Project yielded the following findings: "From victim interviews, we learned that in 87% of the break-ins that occurred when intruders defeated locked doors with tools such as screwdrivers or crowbars, the burglars targeted "the one door that had no deadbolt lock ... not one burglar attempted to break a double-pane window during the course of successful or attempted burglary."

Door security devices

 * Alarms — designed to warn of burglaries; this is often a silent alarm triggered when a door is opened while the alarm is active and the police or guards are warned without indication to the burglar, which increases the chances of catching him or her.


 * Burglar Deterrent CD or MP3s — Home occupancy sounds recorded on a CD. The CD is played when the home owner is away, to mimic the home occupancy activities.


 * Deadbolts — many manufacturers make deadbolts that are resistant to impact failure, picking and lock bumping. However, most deadbolts are not very secure.  Consumer Reports Magazine's testing showed that many manufacturers make deadbolts that break apart and otherwise fail when force is applied to the door.


 * Door strike reinforcers — In general there are two products: frame reinforces, made to prevent delamination and or splitting of the door frame, and strike plate reinforcers, made to prevent the strike plate from being ripped out of the frame. Frame reinforces are metal strips installed vertically on or behind the door frame, on the hinge side they are known as Birmingham bars and on the strike plate side are known as London bars. Strike plate reinforcers secure the deadbolt pocket beyond the thin door frame material, directly to the stud or other wall.


 * Door reinforcements — various products are made to prevent delamination and or splitting of the door. Sheet steel plate can be placed behind or under the deadbolt and wrap the door edge to prevent breaking the door around the deadbolt. Heavy duty products that place plates on either side the door tied together with screws or bolts can be used to prevent delamination.


 * Door chains — allows the doors to be opened slightly to view outside while still remaining locked.


 * Secondary, internal locks — sliding bolts, hooks and specialty latches, metal blocks or bars mounted internally.


 * Door viewers — small fish-eye lenses that allow residents to view outside without opening the door.


 * Door windows — there are three common methods to add security to windows in or beside doors: security bars and grates, security films (coatings applied to the glass in windows to reinforce it), or breakage resistant windows (plexiglas, lexan, and other glass replacement products).


 * Hinge screws — longer or specialized screws that prevent the door from being simply pulled out after removing the hinge pins. Often the hinge pin itself is screwed, from the inside while to door is open, into the hinge to prevent removal of the hinge pin without first opening the door.


 * Sliding door / patio door locks — there are numerous specialized products to prevent sliding doors from being defeated easily.


 * Visibility — Most police departments recommend shrubs be cleared from near doorways to reduce the chance of a burglar being hidden from public view.