While all exterior doors should have equal resistance to forced entrance, the front door is the most important one to make secure.
It is the most obvious, usually the easiest to get to, and is the first one tried by a burglar. The quality of the door itself as as important as the lock installed. Steel doors or solid core wooden doors provide satisfactory resistance against forced entry.
Hollow core doors are filled with corrugated cardboard and are easily broken through. Any hollow core door should be replaced or at least reinforced with exterior-grade plywood applied to the outside of the door.
Stile and rail doors have stiles and rails as part of the face of the door, while the remainder is composed of inset glass or wooden panels which can easily be forced. The panel edge is the weak point in a stile and rail door and should be reinforced with exterior-grade plywood.
The first order of business with double doors is ensuring that one door is braced to reduce the inward give of the doors. This leaves only one door active.
Patio doors present several security problems:
To stop patio doors from being lifted out of their frames, "jimmy-plates" or screws should be mounted at the top of the tracks to reduce any vertical play in the doors.
A "Charlie Bar" folds down horizontally and blocks movement of the sliding portion of the door. This type of locking device offers the additional advantage of high visibility, which may deter potential intruders, and is easy to install.
Auxiliary bolts, which operate with or without keys, can also be installed at the top or bottom of patio door tracks. Numerous types of patio door locks are available with varying levels of effectiveness. Consultation with a locksmith will ensure that you have the proper lock installed.
A metal rod, broom or hockey stick cut down and fitted snugly along the bottom of door tracks is an easy do-it-yourself method of preventing patio doors from being forced open.