Doors, locks, and credit cards

10 years ago

It's always been my understanding that when installing a key-lock door knob for exterior doors, you install it with the flat part of the latch facing the exterior so that you can't slide a credit card in and pop the latch.

I now have an elderly locksmith in the house insisting that this is the OPPOSITE of the correct way to install such locks, that the slanted side is supposed to face out, and that it is fine that someone with zero lock-picking skills can pop any such lock with a credit card.

This would be the locksmith hired by the shady land lady who insisted to my son that the landlord is not responsible for providing working locks (both the front door and the garage door locks will not work with a key, they jam and cannot be opened from the outside). Her solution up to now has been to tell tenants not to lock the side door into the garage and go in and out that way, and to use a credit card on that door should one "forget" and lock the door.

Am I remembering incorrectly? I know it is true that a PROPERLY INSTALLED deadbolt is the far safer lock option (though most aren't properly installed, just locking into the decorative moudling around the door and you can kick the door open). But in order to maximize the utility of the doorknob type locks, shouldn't the flat part of the latch face the exterior, so you can't just slide a credit card in there and pop the latch?

Comments (2)

Pyewacket
Original Author
10 years ago
I think I finally remembered how those latches are supposed to work. There's a dead latch (smaller straight bolt) on the flat side of the latch which is supposed to be depressed by the latch plate when you close the door, then it "locks" the curved part of the latch so you cannot EASILY force it with a credit card. It can still be forced but its a lot harder. Any 3 year old with a doubled-up coloring book cover could pop this thing the way its installed right now.

This is (or has) a dead latch, but the wrong plate is installed and it doesn't depress the dead latch.

If that locksmith didn't know that he's not very knowledgeable - even *I* "knew" that at one time, even if it did take me half an hour to remember it, and I'm not a professional locksmith, LOL!
renovator8
10 years ago
If the door opens into the house, the locksmith is right, otherwise the latch would not allow the door to close without turning the knob.

To defeat a tool, there should be a narrow rod on the inside of the latch bolt that stays in place when someone tries to force the latch bolt. But using a tool is difficult because the door stop is in the way and a credit card would have to be very thin and very flexible. Unless the fit of the door is very loose, a credit card would probably get damaged. a laminated card would be better. If your door opens out and then the hinges could be attacked.

Obviously a latch bolt is not considered a secure lock; you need to also add a deadbolt. In a high quality installation a latch bolt and a dead bolt would open when the inside knob is turned. This is required by law in hotels so that is what it is called. It requires mortise hardware; if you want security you have to pay more.

As for jammed lock sets, either some part is broken or the strike needs adjustment or the mechanism needs to be lubricated. The last two possibilities are easy to fix.

This post was edited by Renovator8 on Sat, Jul 20, 13 at 18:54
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