Pre-hing door issues

[Gregory Massi]

Hey Everyone

I am fairly new to carpentry and having an issue hanging pre hung doors. For some reason I can't get the hinge side gap and the strike side gap to be consistent with each other. Individually each side is consistent but the strike side gap is roughly an 1/8 inch bigger than the hinge side gap. Do you guys have any suggestions? I made sure the hinge side was plumb prior to fastening so I am not really sure what is going wrong.

[Jon Holdman]

Your rough opening (the 2x4s) should be about a half inch to an inch larger than the outside of your pre-hung door unit.   I start with the hinge side.  If I've done a good job on framing, that side will be plumb in both directions and I can just nail up the hinge jamb.  Just a couple of nails at this point.  You want to also check the floor.   You might have to shim the hinge side off the floor, if the knob side is higher.  Or trim the jambs down a little.

Now, with the hinge side tacked in place, go to the knob side.  Here you'll have to shim it away from the framing.  Use shims in pairs so the outsides are parallel.  Get the shims in place so the jamb ends up with a uniform gap between the door and jamb.  You want to be sure you have shims above and below the strike plate so its solidly in place.  You may also have to shim up or trim the bottom of the jamb so there's a uniform gap at the top of the door.

If things go badly, use your sawzall to cut the nails out and start over.