If you have a lot of interior doorknobs with key locks on them, sooner or later you're bound to lose the key or lock them inside the room. Here's what to do to get back in.
When one of my interior doors got locked with the keys inside recently, I learned all I ever wanted to know about lock-picking and doorknob assembly. Locksmiths are expensive, so let me share everything I tried and show you how I eventually got the door open.
If the doorknob in question is a simple push-button affair, most of the time all you need to do is jab a paperclip in the hole and push on the locking mechanism. If the doorknob just has a slit on the outside handle, a butter knife should do the trick.
Keyed locks are a bit trickier to open but it can be done. The easiest approach is to grab a paperclip and tension wrench. If you don't have a tension wrench handy, a very small hex key (roughly the same diameter as the paperclip) will do in a pinch. Take a hammer and flatten the end of the paperclip as flat as you can get it, then grab your makeshift lock-picking tools and head to the door. eHow explains what to do next:
Insert the flattened end of the paperclip above the tension wrench. Push it in until you meet resistance. This is the first pin of the lock. Push up on the pin with the paperclip to try and move it out of the way. When it works, the tension wrench will turn a little further. Hold the wrench in this position, still applying pressure so the pin doesn't drop back down.
Take the paperclip out and push it back in again. When you meet the resistance of the next pin, push up on it as well until it moves and the tension wrench turns. Repeat this procedure with the rest of the pins until the lock opens.
Some lever-type doorknobs respond nicely to the credit card treatment and let you pretend you're a secret agent while you get the door open. wikiHow says just slide the card into the crack in the door, right where the lock is.
Tilt the card so the side that's closest to you is almost or is touching the doorknob. Push it until you feel it slide in more. Bend the card the opposite way, forcing the lock to go back. Quickly open the door. It is a good idea to lean against the door while doing this, which will help it to pop open.
If you want to go all Macgyver on the locked door, grab a vacuum cleaner, dental floss, and a piece of paper. Use the step-by-step guide over at Instructables to show that locked door who's boss.
Sometimes, no matter what you do, the lock just won't budge. In that event, it's time to just remove the entire assembly. Slide a butter knife under the collar where the doorknob meets the door and pop the collar loose so you can get at the screws holding the doorknob together. Once the screws are removed, the doorknob will come apart and you'll be able to easily slide back the mechanism holding the door closed.
If all else fails, there's nothing a hammer wont fix. First, give the doorknob itself several good poundings until it's good and dented. This does absolutely nothing to help unlock the door but it's a great way to get back at the lock that's giving you so much trouble.
Next, insert the claw end of the hammer underneath the top of the doorknob's collar. Put a stiff piece of cardboard where the hammer meets the door to protect the paint. Cover the knob with a thick towel in case metal parts go flying, then yank the hammer down hard. Do this a couple of times until the screws holding the doorknob together snap.
When you go to the hardware store to buy a new locking doorknob, be sure to have some spare keys made while you're there.
How to Open a Door With a Credit Card [wikiHow]
How to Open a Locked Door the Macgyver Way [Instructables]