Suppose, just hypothetically speaking, you live in an 85 year old house with just one full bath and one half bath.
Suppose, again hypothetically speaking, your four year old son managed to make the full bathroom door lock itself after he left the bathroom. The full bathroom has no windows, and is on the second floor. It is completely enclosed.
The lock on the full bath is a mortise lock similar to http://www.historichouseparts.com/images/0216-03.jpg ; but there is no keyhole on the outside; the lock itself is only on the inside.
Hypothetically speaking, how do you open the door?
Hypothetically speaking, do you let the son live?
The 12 Angry Men Blog 
May 2, 2009 at 1:49 pm
I’ll assume the hypothetical locksmith is on vacation and can’t be reached, so …
Remove the moulding from the lock side of the door. The door frame might not be flush with the wall framing, so you might be able to get access to the locking bolt from the side and coerce it back into the lock with a little force applied to the end of it.
As for the son, you let him live, but you never let him live this down.
Hypothetically speaking of course. 🙂
May 2, 2009 at 2:39 pm
And then change the lock…
May 3, 2009 at 9:33 am
Once I got locked in the bathroom when the doorknob came off in my hand due to a stripped screw I didn’t know about. Not fun but far better than being locked in an elevator for over an hour.
May 3, 2009 at 10:36 pm
Maybe a silly question, but does the door open out or in? If out, hinge pin removal may be the way to go.
May 4, 2009 at 6:43 pm
The hingest are on the inside of the room.
May 6, 2009 at 3:39 pm
I would go along with Brian Antoine.
Remove the molding and then credit card the lock.
An alternative, if the attic is unfinished, is to cut out a chunk of the ceiling and lower someone down to open the door from the inside.
May 6, 2009 at 7:57 pm
We ended up calling a locksmith. Not only was he able to open the door without removing any of the molding he installed a little access hole that lets us unlock the door from the outside.
Sadly, there is no access to the attic.
I don’t think the credit card trick would have worked. The lock has a deadbolt and a latch.
I wish I knew how the locksmith did it. Sadly, I wasn’t home when he came and my wife didn’t pay any attention.
May 7, 2009 at 3:25 pm
I don’t think the deadbolt was in play. That would have to be activated from the inside or by a key from the outside.
What I’m guessing happened is that you son pushed in one of the buttons above the latch on the edge of the door. That activates what the night lock so the door locks behind you when you go out.
Newer lock have a two-part latching mechanism. The large part fits into the hole in the striker plate. The small part gets pushed in by the striker plate. That prevents the large part from being pushed in by a credit card. Older locks like the one in the picture that you referenced have a one-piece latch and usually fall victim to carding.
May 7, 2009 at 6:16 pm
Ah, but the deadbolt was in play. We were able to recreate the problem afterward by playing with the door.
The deadbolt acts like ti has a spring. I’m not really sure what is going on, but as your turn the deadbolt’s handle on the door it moves slowly out of the door and then suddenly springs all the way out.
If, hypothetically speaking, you were to play with deadbolt handle (even though you had been told not to) you could leave it right at the tripping point. If you were to then slam the door shut hard enough (even though you’ve been told not to) you’d find out that you had sprung the deadbolt the rest of the way.
I can do this reliably from inside the bathroom.
July 27, 2009 at 8:18 am
I would vote for remove the moulding but alas, locksmiths are really better at seeing the job done. So calling up a locksmith and let him do it, rather than removing the moulding yourself is a hassle-free way and better thing to do.
An I agree with Coasty: change the lock.