Tip 1: Shim before the door goes in
You already know
approach to hanging
a door: Set it
in the rough opening,
then level, shim and nail it. This
traditional approach works fine in a
perfect world where walls are always
plumb, floors are level and you have
plenty of time to fuss with the fit. But
in the real world, some nonstandard
tricks can help you finish the job
faster and better.
The usual method of holding the door frame in place while you shim behind
the hinge side is awkward. It's a lot easier to shim the hinge side of the rough
opening before you put in the door frame. After that, it's a simple job to set
the frame in place, screw or nail it to the shims, and then shim the strike
side. Measure the width of the rough opening before you start shimming to
see how much shim space is available. Usually the rough opening allows for
about 1/2 in. of shimming on each side of the frame. If the rough opening is
extra wide, you can use fewer shims by tacking scraps of 1/2-in. plywood at
the hinge locations first, and then add shims to plumb the jamb.
Tip 2: Make sure an exterior door clears the rug
Most of the time, you can simply set your
new exterior door frame directly on the subfloor
and the door will easily clear carpeting
or a throw rug. But if you're replacing an old
door with a thick sill, or if the floor will be
built up with tile, thick carpet or an extra
layer of wood, you could have a problem.
And there's no easy solution after the door is
installed. You can't simply trim the bottom,
because then the door won't seal against
the sill. To avoid this problem, add a spacer
under the door before you install it. The key
is to determine where the top of the tile,
carpet or throw rug will be, and then raise
the door frame to leave about a 1/2-in. space
under the door (photo).
Tip 3: Set interior jambs on spacers
If you set the door jambs directly on the subfloor, there's
a good chance the door will rub against the carpet later.
Of course, you can cut off the bottom of the doors, but
it's easy to avoid this extra work by planning ahead.
Find out the thickness of the finish floor and then calculate
where the bottom of the door will be. Plan the
installation so there will be about 1/2 to 3/4 in. of space
under the door. Usually setting the doorjambs on scraps
of 3/8- to 1/2-in.-thick trim will put the door at the correct
Tip 4: Hidden screws make exterior doors stronger
There are many benefits to using screws rather than
nails to install exterior doors. They can be adjusted and
won't easily pull out or loosen. But you don't want to
leave the painter with the task of filling big, ugly screw
holes. The trick is to hide the screws under the weather
stripping on the latch side. On the hinge side, you can
simply replace one screw in each hinge with a matching
3-in.-long screw. Always start by drilling a clearance
hole that allows the screw to slide freely in and out
of the hole. This ensures the screw will pull the jamb
tight to the shims, and allows for adjustment if needed.
Don't let the spinning screw rub against the weather
strip—it will slice right through. I know this from bitter
Tip 5: Tune up the rough opening
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 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 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 shims with a fine-tooth saw or a utility knife.
Tip 6: Trim the bottom to level the top
Old houses are notorious for having sloping floors. Even
some newer houses settle in unexpected ways. If you
don't cut the 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.
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Tip 7: Hide screws behind the hinges
Screws are better for securing the hinge jamb because nails
can work loose. You can easily replace one of the short
hinge screws with a long screw, but it can be difficult to
find a strong screw that matches the other screws. Here's
a trick we learned. Hide the screw behind the hinge. It
only takes a minute or two to remove all the hinges and
gain access to this area. Then you can drive a self-drilling
screw through the jamb with ease. Make sure the jamb is
straight and plumb before you reinstall the hinges.
Door Won't Latch
Out-of-plumb jambs or a warped door can cause this. If the
door won't latch because it's hitting the latch-side stop on
the top or bottom, the fix is to move the stop. If it only needs
a little adjustment, you can just tap it over with a hammer
and a block of wood. Otherwise, pry it off carefully, and with
the door closed and latched, reinstall it against the door.
Door Binds and Resists Closing
If the door isn't rubbing against the jamb, but there's tension
when you try to close it, then it's binding on the hinge jamb.
Usually this means you haven't shimmed correctly and the
jamb isn't at a right angle to the wall. Fix this problem by
adjusting the hinge-side shims to twist the jamb back to a
right angle with the wall.