Tips for Hanging Doors from a Veteran Carpenter (DIY)
John Castro Step 5
Tune up the rough opening
How to build a door frame right: Check for plumb
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Check both sides of the door opening. If they’re more than 1/4 in. out of plumb, adjust them before you install the door.
Nudge the wall
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Protect the wall with a 2×4 scrap while you move the bottom of the wall over with a sledgehammer. When the wall is plumb, toe-screw the bottom plate to the floor to hold it in place.
Twisted or out-of-plumb rough openings raise havoc with door installations. If you install the jambs to follow the walls, the door is likely to swing open or shut on its own. On the other hand, if you plumb the jambs against the out-of- plumb rough opening, the trim will be hard to install.
As long as the bottom of the wall isn’t held in place by flooring, there’s a simple solution. Just move the studs on both sides of the opening back to plumb. Don’t think you can do this with your trim hammer, though. You’ll need a maul or a sledgehammer.
How One Pro Installs a Door in Four Easy Steps
John Schumacher, owner of Millwork Specialties Ltd. in Minnesota, has been installing doors and millwork for more than 20 years. He’s learned to avoid callbacks by doing the job right the first time. Here’s his door installation method in a nutshell.
1. Plumb the hinge jamb
The hinge side of the door has to be plumb or the door will swing open or closed on its own. Start by shimming the hinge side of the rough opening. First make marks to indicate the centers of the hinges. Then use a long level or a long, straight board along with a short level to plumb the shims. Tack a pair of tapered shims at the top hinge. Then install the bottom shims and finally fill in the middle.
2. Screw the hinge-side jamb to the stud
Remove the door from the frame and set it aside. Remove the hinge leaves from the jamb. Set the door frame in the opening with the jamb resting on the finished floor (Photo 2) or on a spacer. Drive 3-in. screws through the jamb where they’ll be hidden by the screws.
3. Adjust the gap along the top
Slide shims between the floor and the latch-side jamb until the head jamb is level. Now reinstall the door hinges and the door. Adjust the door shims under the latch-side jamb until the gap between the top of the door and the top jamb is even.
4. Shim and nail the latch-side jamb
Shim behind the latch-side jamb to make an even gap between the door and the jamb. Usually three or four sets of door shims, evenly spaced along the jamb, are plenty. Drive two finish nails into each set of shims to hold the jamb in place. Cut off the protruding door shims with a fine-tooth saw or a utility knife.
Step 6
Trim the bottom to level the top
Check with a level
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Level across the opening and shim up one side until the bubble is centered. The distance between the level and the floor tells you how much to cut off the jamb.
Cut the high-side jamb
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Trim the jamb with a fine-tooth saw. A “Japanese”-style pull saw cuts fast and leaves a clean cut. Old houses are notorious for having sloping floors. Even some newer houses settle in unexpected ways. If you don’t cut the interior door jamb to compensate for the out-of-level floor, you could have a problem getting an even space between the top of the door and the head jamb. This is critical if you’re installing a door over existing flooring where the jambs have to fit tightly to the floor. Photos 1 and 2 show how to trim the jambs to fit a sloping floor.
