Conventional wisdom states that putting a deadbolt on a front door makes it more secure. That wisdom is so good, that people go beyond the conventional wisdom and put two or even three deadbolts on their doors.
Do you know why they do that? Is it really more secure, or is that just paranoia?
In actuality a deadbolt isn’t all that secure. It looks secure; after all, it’s a 7/8: thick steel rod. But to see how secure it is, you don’t look at the strongest part of the system, you have to look at the weakest.
In the case of your average front door, the weakest part is the door frame and striker plate.
Door frames are made out of 3/4″ thick “whitewood” which is usually some variant of pine. The edge of the hole that is drilled for the deadbolt is only 1/2″ to 3/4″ away from the edge of that frame.
On top of that, a 1/16″ thick striker plate is attached with 3/4″ long screws. So, all the strength that is holding the door in place is a 3/4″ square piece of pine.
How well do you think that will hold up to a 200 pound man kicking in the door?
All it takes is one kick, and the deadbolt breaks through the door frame, leaving the house wide open. So much for security.
To make that door secure, you need a much stronger locking mechanism. Since the deadbolt itself is sufficiently strong; what’s really needed is a stronger door frame.
There are several things necessary to make that door frame stronger.
First of all, by making the door frame stronger. This is accomplished by replacing the striker plates with a security striker plate. These are plates which combine the door latch plate and the deadbolt plate. The overall length is about a foot, which allows the force of the kick to be spread across a larger area.
The next thing that’s needed is stronger wood. Behind the door frame are two 2″x 4″ studs; part of the home’s structure. Attaching the striker plate through the door frame and into the studs with 3 1/2″ case hardened screws adds a lot of strength (as you can see in the pic below, the screws need to go all the way into the 2×4 studs of the frame for the most security).
You can buy “security striker plates” at any home improvement center. However, these are usually only a foot long (or less). You can also just make your own.
Making your own security striker plates is easy, especially if you have a drill press.
Start with a three or four foot long piece of 1 1/2″ x 1/8″ steel strap, which you can buy at any home improvement center. Start by marking the centerline of the steel, all of the holes you make in it should be on that centerline.
Measure the distance between your door lock and your deadbolt, and mark off that distance in the center of the piece of steel. You will need to make 1″ diameter holes for these, through the steel strap. This is best done with a high quality hole saw in the drill press. Put a couple of drops of oil on the metal to lubricate the cut and keep the hole saw from overheating.
Double check your work, to make sure that you got the spacing right. Then, measure and mark off the placement of the holes for your mounting screws. You want to put screws every five to six inches, along the entire length of the piece of steel, especially between the two lock holes.
You will need to drill 3/16″ holes for the hardened drywall-type screws to go through. If you choose to use a different type of screw, you might have to drill larger holes. Be sure to countersink them as well, so that the screw head will sit flush with the plate.
One final piece of machining that needs to be done before painting is to grind the edge of the plate at a 45 degree angle, next to the hole that the lockset goes into (not the deadbolt). This is to allow the lockset to spring back and latch when the door is closing. When mounting, this ground portion of the plate needs to be facing into the house, so that the angled side of the lockset’s bolt will encounter it.
The security striker plate replaces your normal one, so you will need to remove the old ones. If there is a large gap between the door and the frame, it may be possible to install the plate, without modifying the frame. However, in most cases, a recess will need to be cut into the door frame to accommodate the new striker plate.
Mount the plate using 3 1/2″ case hardened screws. It helps to drill a 1/8″ pilot hole for the screws. The screws will go in easier if you put dish soap on the points of them, to act as a lubricant.
Put it all back together and you now have a much more secure front door striker plate and deadbolt setup.