door and frame
UV- and water-resistant finish; at the very least,
Head
prime or seal all sides and edges.
casing
Hardware. Hardware for prehung doors is
Top of
installed at the factory, then locksets and door
top hinge
7 in.
handles are removed to prevent damage during
shipping.
As indicated in “Sizing Hinges” at right below,
Jamb
casing
hollow-core or solid-wood interior doors up to
13⁄8 in. thick can be supported by two 31⁄2-in. by
Equal
31⁄2-in. (opened size) hinges, whereas 13⁄4-in.-
thick exterior doors usually require three 4-in. by
4-in. hinges. Extra-heavy exterior doors may
need even bigger hinges or hinges with ball bear-
Center of
ings or grease fittings.
middle hinge
As shown in “Mortise Lockset” on p. 122 and
“Cylinder Lockset” on p. 123, exterior locksets are
most often cylinder locks, which require a 21⁄8-in.
hole drilled through the face of the door, or a
mortise lock, which is housed in a rectangular
Equal
mortise cut into the latch edge of the door.
Lockset centered
Mortise locks are more expensive and difficult to
36 in. to 38 in.
above floor
install, so they are most often used only on entry
Bottom of
doors, with a thumb-lever handle. For added
bottom hinge
security, supplement exterior-door locksets with a
dead bolt and a reinforced strike plate.
11 in.
Double exterior doors may have interconnected
locksets and flush bolts or surface bolts. Interior
locksets are almost always some kind of cylinder
lock: passage locks or latch sets on doors that
don’t need to be locked and privacy locks or lock-
sets on doors that do need locking, such as bed-
room doors. Bathroom locks are specialized lock-
Sizing Hinges
sets with a chrome bathroom-facing knob to
opened hinge
door
door
match plumbing fixtures.
size (in.)
Thickness (in.) WidTh (in.)
Instal ing an Interior Door
31⁄2
11⁄8–13⁄8
Up to 32
Prehung doors come preassembled in a frame,
4
11⁄8–13⁄8
32–37
with the door hung on hinges and held shut (for
shipping) by a single screw through the latch
41⁄2
13⁄8–17⁄8
Up to 32
jamb into the edge of the door. Or the door
5
13⁄8–17⁄8
32–37
may be secured with a removable plastic plug
through a predrilled hole where the lock will go.
5, extra-heavy
17⁄8 and up
37–43
When your doors arrive at the work site, store
6, extra-heavy
them in a dry place out of harm’s way, with their
17⁄8 and up
43 and up
packaging undisturbed until you’re ready to
install them. Because millwork can absorb mois-
ture, store the door(s) in conditioned space
if possible.
There are as many ways to install a prehung
door as there are carpenters. In general, opin-
ions fall into one of two camps: those who favor
Doors, Windows, and Skylights
107
leaving the door on the hinges while installing
earned his stripes building tract homes in
the frame in the rough opening (Method 1), and
100°F summers, it favors speed and economy
those who favor pulling the hinges and removing of movement.
the door, installing the frame, and then replacing
the door in the frame (Method 2).
CHeCkINg AND
P R O T I P
There’s no one right way. Method 1 is some-
PRePPINg tHe OPeNINg
what quicker, but it requires a second set of hands
For aesthetic reasons, the top
It’s helpful to assess the rough opening (RO)
and constant communication between you and
of a new door should be the same
closely and develop a plan of attack. If you know
your helper on the other side of the door. Leaving
height as that of nearby doors
exactly what you need to do, you can reduce the
the door in the frame also reduces chances that
and windows. try to match that
number of times you put the frame in and out of
you’ll damage the door. However, if you’re working
height exactly because the eye
the opening, which eats up time.
notices even slight discrepancies.
alone, method 2 is probably the way to go. The
frame will be a lot lighter and less unwieldy if you
1. Measure the height and width of the rough
take the door out first. And by being able to see
opening. ROs are typically 2 in. wider than the
both sides of a jamb as you shim and adjust it,
door, which allows 3⁄4 in. for the thickness of each
you’ll be more likely to get it right the first time.
jamb and about 1⁄4 in. to shim on each side. RO
The photo sequence on pp. 109–111 is a varia-
height is usually 82 in. from the subfloor, which
tion of method 1. Learned by a carpenter who
leaves 3⁄4 in. for the thickness of a finish floor,
Prep Steps
Start by surveying the rough opening. Check
the dimensions of the rough opening, the thickness
of walls from finish surface to finish surface,
whether trimmer studs are plumb, and make sure
the floor is level.
. . . and use a square to mark the bottom of the high-side
jamb. Cut off the amount that side is high, reinsert the frame
in the opening, and check the head jamb for level again.
For best support, side jambs should rest on the subfloor or
finish floor. Some carpenters start their installation by
standing the frame in the opening to check the head jamb for
level. If it is not level, note by how much, remove the frame . . .
Use a square to see if jamb edges are flush to finished walls. If the jamb
edges are flush or slightly proud (projecting beyond drywall), casing
corner joints will meet. However, if the jamb is shy (shallower than the
drywall), mitered joints will gap.
108 Chapter 6
approximately 1⁄4 in. of clearance under the door,
a standard 80-in. door, the 3⁄4-in. thickness of the
WHere Dissimilar
head jamb, and room to shim.
FloorIng MeeTS
2. Measure the thickness of the wall, from fin-
ish surface to finish surface. Interior 2x4 walls
if a doorway is a juncture between different fin-
covered with 1⁄2-in. drywall are 41⁄2 in. thick, so
ish floors—say, wood and ti
le—a square cut
standard jamb stock is 49⁄16 in. wide, providing an
across the bottom of the jambs won’t be possi-
extra 1⁄16 in. to accommodate wall irregularities
ble because the floors’ thicknesses will vary. in
when you install the door casing. If your building
that case, let the jambs rest on the subfloor and
plans call for 5⁄
P R O T I P
8-in. drywall, which would produce
notch the flooring around the jambs. cover the
a wall 43⁄4 in. thick, specify jamb stock 47⁄8 in.
joint with some kind of transition strip, typically
thick when ordering a prehung door.
In general,
a prefinished oak threshold trimmed underneath
use pairs of shims
3.
with their tapers pointing in
Check the opening and remove anything
along one side to accommodate the thicker
opposite directions to create an
that could interfere with installing the door.
flooring. run a bead of silicone under both
even gap between a door jamb
Occasionally, installers will run drywall past the
edges of the threshold so it will stay put.
and a stud. Wood shingles make
trimmers, so cut it back so it’s flush with the edge
great shims because they taper.
of the opening. Likewise, if a sole plate protrudes
Occasionally, when a stud is
into the opening, use a reciprocating saw to cut
slightly twisted and so creates a
it flush.
tapered gap, you’ll use just one
allow 1⁄
4.
2 in. of clearance between the bottom of
Check that the subfloor or floor is level and
tapered shim to fill that space.
the door and the finish floor.
the trimmer studs are plumb. If the floor slopes,
you will shorten the jamb on the high side so the
4. If the finish floors are not yet installed,
head jamb will be more or less level. Whatever
stand the side jambs on scrap blocks of flooring.
installation method you use, the crucial step is
When it’s time to install the flooring, just pull out
plumbing the hinge jamb of the frame. So, as you the blocks and slide the finish flooring under the
assess the RO, pay special attention to the trim-
jambs. Otherwise, the flooring contractor would
mer stud on the hinge side. If it’s not plumb, note have to notch around the jamb profile, which is
which way it leans.
time consuming. Alternately, you could let the
jambs rest on the subfloor and, later, the installer
SettINg tHe FRAMe, AND
could use a flush-cutting saw to trim the jamb
tACkINg tHe HINge jAMB
bottoms so he could slide the flooring under.
5. Having trimmed the jambs as needed, once
Again, the photo sequence depicts method 1, in
again margin the hinge jamb in the RO, and tack
which the door stays in the frame as it’s installed.
it to the trimmer stud, using three 8d (21⁄2-in.)
1. Stand the door frame in the RO. Starting
finish nails, one nail below each of the three
with the hinge jamb, use a Speed Square to mar-
hinges. Now you’re ready to plumb the hinge
gin the frame—that is, to center the door frame
jamb. (As the door is mounted and closed at this
within the thickness of the wall. If the jamb stock point, open the door to nail off the jamb.)
was correctly sized, the jamb edges will be more
or less flush to finish surfaces on both sides.
SeCURINg tHe FRAMe,
2. As one person holds the frame in place
AND FOllOWINg tHe ReveAl
against the hinge jamb, the other checks the
height of the unit and the RO. Ideally, there
1. Holding a 6-ft. level to the hinge jamb, drive
should be 1⁄
shims between the door jamb and the RO until
2 in. of clearance between the bottom
of the door and the finish floor. If the floor is
the jamb is plumb. Because finish nail shanks
level, remove the frame from the opening and, as are small, one nail won’t offer a lot of resistance
needed, use a circular saw to trim an equal
as you drive a pair of shims behind it. In other
amount from both jamb legs. Replace the frame
words, the nail will hold the jamb in place but
in the opening, and use a level to check the head
can be pulled out slightly. To avoid bowing the
jamb for level.
jamb, place shims directly behind the hinges
if possible.
3. If the floor slopes, you’ll need to remove
more from the high-side jamb. Remove the frame
2. Once the hinge jamb is plumbed, nail it off
A. Plumbing the hinge jamb is the
from the opening, use a circular saw to trim the
in earnest, using two 8d nails per shimming
critical part of most door
bottom of the jamb, replace the frame in the RO,
point. Drive these nails through the pair of shims. installations, so get a sense of how
and check the head jamb for level. Here again,
In addition, remove the middle screw of each
much shimming you’ll need to do to
make that side plumb.
Doors, Windows, and Skylights
109
trimming Doors
When the door swings open, it should not “pattern” your carpet or abrade the finish
floor. If it does, trim the bottom rail of the door. to register the height of the carpet on
the base of the door, slide a flat builder’s pencil across the carpet. the pencil, being
flat, won’t sink into the carpet as much as a round pencil would. Add 1⁄8 in. of clearance
to that rough line and score the final cutoff line onto the door, using a utility knife
drawn along a straightedge. Scoring the door is important because it prevents wood
grain from splitting and veneer from lifting and splintering. Run the circular saw a
whisker below that scored line and you’ll get a nice, clean cut.
For best results, use a circular saw with a sharp Mastercut® blade, which has a close
configuration of at least four fine teeth and a raker to clear chips. Use a straightedge
clamped to the door to guide the blade. Clean the saw sole (base plate) well: Degum it
with turpentine (or paint thinner) and steel wool, then rub it with a metal-polishing
cloth or paraffin to help it glide across the wood. Smooth the cut, and ease the edge
with 220-grit sandpaper, sanding with the grain.
B. If you’ve got help, leaving a prehung door in its frame
is generally a faster way to install it.
hinge plate and replace it with a 21⁄2-in. to 3-in.
screw that sinks solidly into the trimmer. Secured
in that manner, that hinge jamb won’t be going
anywhere.
3. Between the door and the hinge jamb, you’ll
notice a slight reveal (gap), typically about 1⁄8 in.,
created at the factory so that the door would fit
C. In this method, margin (center) the hinge jamb in the
closely but without binding. If you maintain that
wall, then tack it to the trimmer stud with just t
hree finish
1⁄8-in. reveal between the door and the frame as
nails—one beneath each hinge.
you shim the head and latch jambs, the door will
operate freely and look good. This method is
called following the reveal, and it works well
because your eye notices the gap first and fore-
most. So you can relax about abstractions such
as plumb and level. Set your level aside if you
110 Chapter 6
G. Margin the latch jamb, tack it to
the stud, shut the door, and continue
reading the reveal between the door
and the latch jamb, adding shim
pairs until the reveal is even. Keep
tweaking.
D. Then, holding your level against the hinge jamb, gently
drive pairs of shims between the hinge jamb and the stud
to bring the jamb into plumb. Because the finish nails
don’t offer much resistance, the jamb will move into
position easily, yet remain tacked to the RO.
H. Once the reveal is even on all
sides, nail the frame securely, using a
like. (If you are using method 2, once you’ve
pair of finish nails at each shimming
tacked the hinge jamb and the head jamb, you
point. To add holding power, some
installers also replace each middle
can set the door back on its hinges.)
hinge screw with a 21⁄2-in. screw that
4. Because you’ve already margined the hinge sinks into the framing.
E. Once the hinge jamb is plumbed and shimmed, margin jamb, that corner of the head jamb should be
the head jamb and tack it with a single nail near the top of centered as well. So, using a Speed Square, mar-
the latch jamb. This holds it loosely in position.
gin the latch corner of the head jamb, then use
two 8d finish nails to tack it to the header. Shut
the door so you can read the reveal between the
top of the door and the head jamb; add shims
and adjust the head jamb so there’s an even 1⁄8-in.
reveal along its length.
5. Next, follow the reveal to the latch jamb.
Margin the latch jamb, tack it in place, and add
three pairs of shims—one at each corner and one
behind the latch strike plate. This step goes best
with a worker on either side of the closed door—
one reading the reveal and advising whether to
push shims in or out at each point. When the
reveal is even along the latch jamb, nail it off
I. Trim shims flush and you’re ready
with two 8d nails through each set of shims. If
to add casing. Here, an oscillating
the jamb stock is straight, three pairs of shims
Renovation 4th Edition Page 26
