About a month ago, I was talking with a friend of mine who's a police officer. We were talking about a number of things in regards to home security, and he mentioned that in most burglaries, the thief just kicks in the door - no problem - because door frames tend to be pretty wimpy. He also mentioned that door frames that were reinforced with a strip of metal were immensely harder to kick in ... and I immediately starting thinking about making my own.
Most residential doors are pretty "soft" - i.e. easy to get through. There are a number of videos on YouTube where you can see someone almost casually kick in a door - and when you understand the actual support structure around most locks and deadbolts, it's pretty obvious why this is the case. While you might have an awesome deadbolt that resists picking and lock-bumping, the only thing REALLY keeping your door closed is a relatively thin strip of wood (probably pine) and maybe some trim - i.e. the relatively thin door jamb.
This instructable covers one possible technique for making a door frame nearly impervious to being kicked in. I want to admit right off the bat that this design is overkill - lol. I have a tendency to over-engineer things and this project was no exception. If I were to do it again, I'd be looking at using 16GA or thinner metal (1/16") as opposed to the 10GA (1/8") metal I used - it would be easier to work with and still very strong.
I also want to mention that there are commercial products out there that do the same thing - but why BUY what you can MAKE when you can make it better? :) I was also able to make the door reinforcement for about half what a much thinner commercial product would have cost (not including time, of course) - total cost was around $22.
What you'll need:
Metal strip - I used a 2" x 48" strip of 10GA 304 stainless steel. I'd recommend 16 GA (which should be even cheaper)
Heavy-duty screws - 4" long (I used hardened decking screws with Torx heads)
Assorted metal files, hammer, cold-chisel, drill, bits, countersink, sander, sanding belts or sandpaper, measuring tape and/or rule, center punch, scribe, welder, metal saw (reciprocating, abrasive, whatever works) and it would be nice to have Dykem and/or permanent markers.
Step 1: Dimensions and Layout
The first thing to do is check how much of a gap you have on the "knob-side" of the door. If you've got the room, you might be able to install the strip on top of the wood, but if the gap is a little tighter (around 1/8") you're probably going to have to inlet the surface of the jamb. I had plenty of room, so I opted to go with a surface-mounted installation.
Next, check how wide of a strip you need. I used a 2" wide strip, but you'll want to make sure that you won't have too much overhang if you go with that dimension. The 2" wide strip was *just* about the right size - I could mash it back against the weatherstrip and get the front edge just flush with the face of the door frame. The commercial units run around 1 1/2", which doesn't seem wide enough to me (another reason to build your own)
Once you have your material, it's time to transfer the locations of your lock and deadbolt catches. Since these catches are usually kind of "tuned" during install, and mine were set up pretty much exactly where I'd want them, I decided that the best technique to get the dimensions would be to scrub-trace them, and save myself a lot of hassle trying to measure it all out. If you use this technique, be *sure* to get the edge of the door frame as a reference since it's the distance between the front of the frame and the front edge of the catch-plate that determine how tightly your door closes (or doesn't close).