I've noticed that some places have a lock in the knob and a deadbolt in the exterior doors, and some places have a knob without a lock and just a deadbolt. Is there a benefit to having a lock in the knob I'm missing?


The lock in the knob can be set to be locked when the door is closed. In other words, you do not have to do anything extra to lock the door, just pull it closed. This can be good or bad depending on how you look at it (it can be easy to lock yourself out this way). The dead bolt on the other hand always requires an extra step to lock the door (put the key in, lock it, and remove the key); this forces you to have a key in hand, preventing you from locking yourself out.

Depending on what you are doing/replacing, also check your local building codes. Some types of deadbolts (the ones that require a key on both sides) may not be allowed in certain situations.

| improve this answer | |
  • Great answer! I've locked myself out in a house with two locks, so I'll stick with a single dead bolt for each door. It's cheaper as well. – Joseph Sep 12 '10 at 14:07

I agree with Jeff and Mike's answers, but you also have to make sure the lock was installed correctly. When I bought my house and changed the locks, I found out that the strike plates installed (deadbolt and doorknob) on the front door were only screwed into the trim with 1/4" screws. It wouldn't have taken much force at all to rip them right out. (My guess is one well-aimed kick.) The new Schlage locks that I bought came with 4" screws for mounting the deadbolt strike plate THROUGH the trim and into the studs behind the frame.

| improve this answer | |

From a security point of view two locks is better than one.

Some insurance companies might require that you have a deadbolt type lock, offering reduced premiums if you have a recognised standard one fitted.

| improve this answer | |
  • 4
    The deadbolt is definitely a better lock than a standard doorknob lock. It is harder to break down or pry open the door with a deadbolt, since it is thicker and goes further into the frame. But really, if someone wants to get into your house, two locks instead of one is not going to stop them. – gregmac Sep 13 '10 at 16:46
  • @gregmac - I quite agree - but insurance companies do have these rules. – ChrisF Sep 13 '10 at 19:53

I completely agree that having more locks can be helpful but also keep in mind that the brand and model also play an important part. AFAIK, some locks (including deadbolts) are still susceptible to bump-key techniques.

Sometimes you really do get what you pay for. ;-)


| improve this answer | |
  • 1
    With the proper tools, basically all locks can be picked or bumped. You can find youtube videos of even the highest security-rated locks being picked in a few seconds. – gregmac Sep 13 '10 at 16:44

It's quite useful to have two locks in the door separating the house/apartment from the surrounding world but use just one of them. Locks happen to break, although that's quite rare. If one of the locks starts malfunctioning you can just stop using it and use the other one until you fix the first one.

I once had such situation - I was trying to lock the apartment and noted that the lock mechanism was just twisted weirdly and the key would fit into it. No problem, I found the key to the other lock, locked the other lock and went to the shop to buy a new mechanism.

| improve this answer | |

Most key-in-knob locksets have some vulnerabilities that make them better as convenience latches than as serious security locks. Adding a separate deadbolt is definitely worthwhile unless you are in a VERY low-crime area... and even then, I'd suggest doing it on the principle of "if you're just a bit more secure than your neighbors, the burglar will bother them instead."

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.