Strike Plates & Kick In Protection - A Practical Guide
What is a strike plate?
A strike plate or "Strike" is a metal plate that is secured to the door jamb for the purpose of reinforcing the latch on the lockset or deadbolt. They come in many different shapes and sizes, for various applications. Beveled, non-beveled, commercial grade, residential grade, deadbolt and door knob styles, full mortise etc. They are an absolutely critical part of the security of any mechanical locking device, deadbolt or door knob. Here's a few pictures of various styles.
Here we have residential Lip-Strike commonly seen on residential door knobs, we also have a commercial Lip-Strike and a residential deadbolt strike.
Common Mistakes and Misconceptions
The biggest issue with these strikes is they often are incorrectly installed, it's critical that they not only mount to the thin 1.5" trim board of the door jamb, but they also hit the stud behind the trim board material. The strikes often come from the factory with tiny 1/2" screws.We recommend replacing them with 3" screws. Furthermore, they are often installed by builders, in a track-home situation. Unskilled workers getting things done as quickly as possible.
Another critical thing to check for is the bore-depth of the deadbolt hole, the physical hole that is drilled into the jamb must be at least 1" deep, or a deadbolt will only extend partially, when a deadbolt does not fully extend, it does not "Dead Lock". What this means for you is, the lock can be "Jimmied". This is easy to test yourself, with your door open, lock your deadbolt, fully extending the throw, now push on the end of the deadbolt throw, if it is fully extended you'll see that it does not move. If we artificially limit the throw to only allow a partial extension, you'll see that the deadbolt does not "dead lock" and can be easily manipulated.
Door knob latches also contain a "Deadlocking plunger" and it is critical that this piece sits correctly on the strike or else, similar to the deadbolt example above, the latch mechanism will not "Dead lock". This means it can easily be "Jimmied" or forced with a screwdriver/knife/credit card. Many people believe that door knobs are inherently un-secure, this is not entirely true, a properly installed door knob or dead bolt can offer a decent amount of security. Taking into consideration a properly installed strike, on an in-swing door. Interestingly even a "passage" non-locking door knob will provide considerable kick-in protection if a strike is properly installed. You often see handle-sets, and passage, non locking hardware on homes in conjunction with a deadbolt, they are more convenient with less locks to mess with, and it's impossible to hold a door knob open and kick a door, so the standard, non-locking latch combined with a properly installed strike still offers credible kick-in protection.
The reason we recommend longer screws is to tie the metal strike to a strong stud behind the trim-board. You need to understand in a kick-in situation the trim board splits, once this happens it will rip the entire trim board in half and blow out, it does not matter if you've got 1, 2, 3, or 4 deadbolts installed on your door, without proper strike installation and reinforcement, that trim board is going to blow out and all those additional locks will do you no good.
I often have to educate customers in the field who are looking for additional security by adding a second deadbolt, that what they really need to do is reinforce the door jamb and strike. This is the best place to spend money and effort. In a kick in situation you are only as good as your weakest link, usually the trim board, and if that is sufficiently reinforced the next thing to go is either the hinges, and/or the door itself, we will discuss reinforcing these things later in the article. Here's a few pictures of some of the things we discussed:
Deadbolt Throw - Make sure it fully extends into door jamb! Very important.
The deadlocking plunger does not go inside the strike pocket! It "Sits" on it, this engages the deadlock! Very important
You'll want to change these tiny stock screws out immediately for the longer 3" screws, make sure they go into a stud!
This is how a typical kick-in situation splits the trim board and blow's out the jamb. Our goal is to stop this from happening, following the tips in this guide will help prevent this. You can see here, that it does not matter how many locks you have on this door once the jamb is split, this is why long screws and heavy duty strikes are critical. When the strike is properly secured to the 2X4 material behind the trim board, the force of the kick is transfered to the metal strike itself, and the 2X4.
Heavy Duty Strikes
Reinforce the Door Jamb
Heavy duty strikes come in a few different options, manufacturers like Don-Jo, and Strike Master Pro are some of my preferred options. However, there are reasonable options available from your local big box stores like Home Depot and Lowes. Make sure they come with long screws. Some of these can be a little difficult to install, may requiring mortising into the door jamb, depending on your particular door. We install these devices at Ready Lock. 210-929-2495
Good & Great Value
Better - More expensive
Best - Most expensive - Can be used for Door Jamb Repair.
Door Wrap Plates
Reinforce the door
Repair damaged door
Door wrap around plates are used to reinforce the door, once the strike has been properly installed, using 3" screws and reinforced, this is commonly the next weakest link. Door Wrap Plates will help strengthen this area. They are also excellent for repairing a door that has already been kicked in, faster and often cheaper then replacing the door, the repair is typically stronger then the door initially was. Ready lock sells and installs these devices as well. 210-929-2495
The Final Step for total security
Lastly, after we have reinforced the Strike and Door lock assembly with the above products, the next weakest ling is typically the hinge side of the door. Like the strike plate assembly, hinge's typically come with tiny 1/2" screws, this is less than ideal. It's somewhat made up for by the fact that their are many screws, typically 3 hinges with 4 screw's each. These tiny screw's however are still merely attached to the 1.5" trim board, we've noticed over time that many door's being to sag on the hinge side, this causes strike mis-alignment and can cause the door to drag the ground and/or threshold. The solution is simple, replace the small screw's with 3" screws that make contact with the stud behind the trim. This will often times pull up a sagging door, and also add significant security and kick-in protection. You may also consider a security hinge, which has a locking mechanism intended to lock the hinge shut if someone attempts to pry the hinge pin's out. This is typically only an issue with out-swinging doors on older properties. Another alternative is Security Hinge pins, which do the same thing as a security hinge, but are designed for retrofit application. At Ready Lock we reinforce door hinges, and on occasion repair sagging door's. 210-929-2495
Reinforce Jamb Strike Plate
Use long 3" Screws
Replace basic strike /w Heavy Duty Strike
Reinforce Door Lock with Door Wrap
Use long screws for Door Hinges
Call Ready Lock if your in San Antonio, Texas area