One of the
most important parts of framing
walls is getting the rough
openings right. Items that
determine what the heighth of
your opening will be are floor
finishes and the use of
underlayment. Door widths will
stay constant with the size of
a standard door.
In new
construction most doors are
hung after the floors are
installed. This allows flooring
contractors (tile, hardwood,
vinyl, laminate) to lay their
flooring products without
making tricky cuts around door
jambs. It also makes for a neat
and clean door installation.
Exceptions to this are carpeted
floors. Doors are hung before
the carpeting is laid. When
doors are hung in carpeted
areas, its a good idea to shim
them up 1/2", putting a shim
under each jamb leg. This
eliminates the need to cut the
doors down after the carpet is
installed.
For a 6' 8"
high door (80 inches) I like to
frame my rough opening heighth
at 82 3/4". This allows room
for all the situations
mentioned above. If your header
material is a
double 2x12, holding it to the
top plate will give you that
heighth.
Rough
openings for door widths are
pretty much standard. The rough
opening width is 2 inches wider
than the door itself. this
allows room for the door jambs
which are usually 3/4" thick.
This gives you approximately
1/2" of play and shim room when
installing a prehung door. For
a 36" door (3' 0") the rough
openig width would be 38". Here
are the most common door sizes
and their rough
openings.
Door
Size
Rough Opening
Size
2' 0" x
6'8"
26" x 82
3/4" 2'
2" x
6'8"
28" x 82 3/4"
2' 4" x
6'8"
30" x 82 3/4"
2' 6" x
6'8"
32" x 82 3/4"
2' 8" x
6'8"
34" x 82 3/4"
2' 10"x
6'8"
36" x 82 3/4"
3' 0" x
6'8"
38" x 82 3/4"
To figure the
rough opening for double doors
or french doors, take the door
size times 2 and add 2". The
most common sizes for exterior
doors are the 2'8" and the 3'0"
doors. The 2'8" is usually used
for the back door and the
access door from the garage.
That size door for exterior use
is being used less these days
because of the size of
appliances and furniture.
Exterior doors with sidelights
and sliding patio doors rough
openings vary from manufacturer
to manufacturer. These should
be verified and gotten from the
supplier.
Getting the
rough openings right the first
time keeps the sawzall in its
carrying case and having to
change the opening after the
walls are drywalled and
painted.
