Installing Interior Pre Hung Doors
Are you a weekend warrior who wants to install a new pre-hung door? Are you experiencing a little anxiety? As they say in Jamaica: No problem!
Let's assume that you created a large enough rough opening. I always make my rough openings two inches wider and three inches taller than the size of the door for standard interior door units. This gives you plenty of room to wiggle and shim the door.
If you took your time in the rough framing and used straight lumber, you should have no problems. Always hang a door starting with the hinge jamb. The rough jamb on the hinge side of the door should be plumb. If this is the case, you can nail the door jamb right to the rough jamb. If not, you will need to shim the hinge jamb to make it plumb.
I always use eight penny finish nails to nail the jamb. Do NOT nail the nails in all the way at this time! Leave them sticking out 1/4 inch in case you have to make adjustments. I put one nail equal in height at each hinge location and at each shim location.
Now let's start on the other jamb. But first, we need to look at the top jamb reveal. Stand on a bucket or a ladder. Look at the gap between the top of the door and the jamb. Is this gap equal? If not, the latch side jamb needs to go up or down to make this gap equal. Do what you have to do to make this gap equal.
The latch side jamb is shimmed to create a similar equal gap. I always shoot for a 1/8 inch gap. No larger! Usually the controlling measurement is what the gap is at the top of the door. The people who milled the door and door frame create this gap measurement. If they did their job right, you simply need to shim the door every 16 inches so the latch jamb is parallel with the edge of the door. Once again, when nailing, don't drive the nails all the way.
When checking for an equal gap, be sure to put pressure against the jamb. You may think the gap is equal, but will be surprised when you nail the jamb tight. Cedar shims can compress and mess up your gap. Be patient and all will go well. If you have to cut off the bottom of the door, be sure to paint or seal it immediately! This prevents warping.