The door is usually manufactured with predrilled holes so that builders or contractors can easily install a lock. Most of the time there are 2 holes. Those holes are indented for the bottom door knob and top deadbolt. While some doors have only one predrilled hole, meaning only one lock can be installed
Drilling more holes in the door does weaken door integrity if the door is primarily made of wood. Because wood is typically soft material and drilling more than 2 locks might weaken that specific drilled area. However, metal or aluminum doors won’t feel much intervention in their structure and security.
There are some methods to reinforce a door while having several door holes. The metal plates on the door and frame will help to withstand most force impact or make sure there is enough distance between drilled holes so that in case of burglary or any cataclysm door can distribute the impact.
How many door holes should be enough?
Generally, two locks on a single door are more than enough in terms of security. Not only locks but also door or frame strength plays a vital role when it comes to precaution. What if you have only a single door knob (which is most case scenarios in many doors that lead to the garage – believe us, we saw that a lot). In that case, you should definitely check why you need 2 or more locks on the same door.
Where door holes should be located so that door strength is not compromised?
Most doors have two locks that are located just to each other. The top lock is a deadbolt and the bottom lock is a door knob. When wood is drilled, there are some cracks that can arise in the drill epicenter. If the crack is big, then it might continue all the way until another lock location. Locks still can be installed next to each other, as long as the door is solid enough. Definitely drilling the third lock is advised somewhere on the top of the door. That way you can distribute the strength of the door if someone tries to break the door and also a great solution to prevent kids from accidentally exiting the house
How do I know if my door can withstand another hole?
Looking to add an extra lock for even greater security? If the door is plastic or even metal made, then you can drill as many locks as you want. However, if the door is made from wood, which is quite common in the United States, then you should question if your door is strong enough. You can check that by examining the side of the door to see if there are any cracks or uneven surfaces. If you find one, then you should not drill an extra lock since it will bring more damage and weakness than security.