How can I accommodate a 2-5/16" door latch backset?

Question

Today I went to replace a non-locking door handle that leads from the house to the garage with a key-secured one, but after grabbing a standard sized latch and handle and trying to install it I realized that the backset is not 2 3/8" or 2 3/4" like normal and instead sits at pretty much exactly 2 5/16".

Being 1/8" less than the standard means that the latch guard doesn't sit flush with the door edge and results in greater sheer forces applied to the strike causing the latch to move a lot when the door closes.

I have looked far and wide for a 2-5/16" backset latch/handle but cannot find them anywhere. Any ideas where I could find one or am I out of luck and need to either fill and re-bore OR get a whole new door?

Answer 1

If the original is a 2 3/8 backset knob or handle, the 1/16" difference in backset should not be an issue.

Be aware, most doors are beveled on the closing edge, so one face of the door will be wider than the other, usually an 1/8". The backset dimension of the latchset is taken from the wider face of the door. and since the latch itself is centered in the edge, it only stands to reason the actual length may be shorter that the stated dimension.

Either way we are talking 1/16". This can be accommodated by shifting the knob or lever in its' bore. Typically when I set latches, I set the strike bolt in the edge of the door flush with the edge. Most, not all latch sets are made so the mounting plate for the catch is at a slight angle to follow the bevel of the door, so it can set flush across the edge of the door. once this is fastened in place, this will dictate where the knob will go. With only a 1/16" difference, it should still slip in. If not, use a file or other means to move the offending edge of the hole over the 1/16" so the knob will slip in without fouling against the knob bore.

There is usually 1/4" of cover by the knob rosette, so it can afford to be shifted over without exposing the bore for the knob on the opposite side.

Answer 2

Replacing a door without a lock might mean that the door itself is an interior door, which generally provides scant to no protection against a solid kick. This is even more important to keep in mind as the burglar would have a private place to kick in the door, with less chance of being seen from the street.

If you are attempting to provide some security between the garage and door, I would remove the frame and get a pre-hung exterior door with a steel skin. Then I would take good measure to ensure it was properly anchored to the wall framing. This way a person who sees a lock won't be successful in just kicking through the door's core.

Also, consider a deadbolt when replacing the old door, but be sure to use an interior latched one, to keep your occupants safe during a fire. Deadbolts are much less likely to fail during an intrusion attempt (and do a little research to avoid those that can be bump picked).