I need a locking doorknob.

August 3, 2008 11:13 AM

I need to install a key-locking doorknob on my bedroom door. What sort of options do I have, and can I do this myself?

Since I still live at home for at least a bit longer, I decided I need a little more security so I can keep my possessions where they should be (my very slightly younger brother seems to have a problem with putting things back where they belong). So, since my bedroom door doesn't lock, I'd like to make it do so, from the outside and inside.

So, my question(s):
1) How easy is this to do? I'm pretty home improvement savvy, so I think I could handle anything as long as I have instructions.

2) Are any key-lock doorknobs better than others? Or are they all pretty much the same? I have access to pretty much every home improvement store, including a small professional locksmith.

Thanks a ton in advance :)

posted by Verdandi to Home & Garden (6 answers total)

If the existing doorknob is "normal" (not an old skeleton key type), just get a keyed lockset and replace it. They are pretty much universal. The new one will have installation instructions, and the old one should come apart pretty much the same way.

Usually, to get the old one apart, there will be a "secret" button on shaft of the interior knob. Push it in with a screwdriver or strong paper clip and the knob will pull out. Then remove the screws on the "wallplate" thing. There may be a decorative cover on the wallplate thing, or it might unscrew to reveal the screws. The rest of the locket will come out the other side. Then unscrew the screws on the door latch and it will come out the side.

It might be useful to then bring that knob to the store to get one that matches.

If the new latch plate is larger than the mortise (the area that it rests in so that it's smooth with the door) use a chisel or stanley knife to carefully expand the area.
posted by gjc at 11:29 AM on August 3, 2008

It's very easy to install a doorknob, provided your existing knob is a standard size. You basically take out a couple of screws and the knob comes out in two parts (one for each side) plus the latching mechanism that slides between through the hole on the side of the door. It's pretty self-explanatory once you take one apart.

You can buy a key-in-knob doorknob kit at any hardware store and pop it right in. If you get one with a real key (rather than the push-button style that are common in bathroom doors and can be picked with pretty much anything that will fit in the hole on the outside) the lock will be secure except against an experienced lockpick. However, key-in-knob locks tend to be vulnerable to a credit card or shim, where you slide the card between the door and the jamb and push back the locking mechanism. Some locks have plates integrated into the strike plate or that you can bolt on the outside to stop this sort of attack. A deadbolt (a lock that installs separately from the doorknob and you have to lock with a key) is impervious to this kind of attack but you have to drill more holes in your door and frame to install it, and it would be a lot more obvious and incongruous in an interior door - but it is also a pretty easy job and kits are available at any hardware store.
posted by nanojath at 11:31 AM on August 3, 2008

its extremely easy, it only takes 2 screws and about 2 minutes. buy a locking knob form home depot or whatever. then go home and unscrew the existing knob. see how the old one went in - the new one will go in in exactly the same way. done.

I've done this for similar reasons (nosy sister) ;)
posted by jak68 at 1:24 PM on August 3, 2008

It's a piece of cake. Take out the existing lock and take it with you to home depot or lowes or what-have-you -- you want to have it with you to know how long the bolt throw is, how far back the knob is set from the edge of the door, just tell the guy there and he'll know what you're talking about -- and buy a new cheapy lock, ten bucks max, take it home and install it. You might need a chisel (to open up the wood a little bit) but you probably won't, most likely all you're going to need is a philips screwdriver.
posted by dancestoblue at 1:35 PM on August 3, 2008

Most of the above is pretty good. I install a lot of locksets and there are three basic kinds: passage (no lock), privacy (bathroom) and keyed (usually exterior). Most keyed locksets now have a sliding thingie on the bolt that renders them impervious to the credit card trick

The bolt-throw referred to above is called backset in the trades. The most common backset is 2 3/8 inches, with the occasional 2 3/4... but 99% of locksets are adjustable for either one. The only real issue with inexpensive locksets is the mortise for the strike plate (on the door jamb) and the mortise for the plate around the bolt in edge of the door. Some have square corners and some are rounded, so look at that because the hardware you buy may give you both... or not. Also you need to match the finish of existing hardware, either brass or silver.

I installed a Kwickset keyed lockset last week that cost 32$ at Lowes and it was the easiest one I ever did. It was harder to get it out of the plastic packaging than it was to install it. Usually you have to sort of blind fish the two screws thru the door and get lucky, but that one just twisted apart and the screws stayed in the outside part so you could just push the heads back thru the holes in the bolt (install that first), twist it back together and tighten with a number two phillips screwdriver. Get a nice stool to sit on while you’re working.
posted by Huplescat at 2:52 PM on August 3, 2008

Nthing easy. Schlage is a pretty good brand for house locks.
posted by Citrus at 9:05 AM on August 4, 2008