Installation Guide

Installing your casing
5. Begin by marking the desired reveal on the door or window jamb. The reveal is the margin
between the edge of the casing and the jamb. This measurement is typically 1/8 of an inch or
the same as the thickness of the moulding where it meets the jamb.
6. Cut your first piece to length. Measure the side of the door jamb. Add the desired reveal
distance to the height and mark your casing on the inside edge.
a. Cut the top end of the moulding at a 45 degree angle. This will leave the outside edge
of the casing longer than the inside. The shorter side will equal your measurement.
Remember, you will be cutting a left hand and right hand side. Cut the piece a little long
and trim as needed to get the best fit.
b. Repeat this process for the opposing side.
7. Cut your header or the piece of casing that will be installed horizontally across the top of your
opening. Measure the distance between the jambs. This time you will need to add the desired
reveal distance twice to the width of the opening. If you are installing moulding on all four sides
of an opening, repeat this process for the bottom piece.
a. Cut a 45 degree angle on one side of the moulding. The inside of the casing will need to
be the short end. Mark your distance from the short end to the opposite side of the
casing. This will need to be the short end of the next 45 degree cut. You should end up
with a left hand and right hand cut on the casing where the inside edge is longer than
the outside edge on both ends.
8. Once your cuts are made, dry fit the moulding around the opening. It may be necessary to trim
the legs and header to achieve tight miter joints. Adjust as needed and then nail into place.
a. Nail the top piece of casing in place. Be sure to line the inside edge of the casing up with
your reveal marks. Use a level to assure that you nail the moulding in place straight
across the top/bottom of the opening. Nail through the casing into the jamb of the
opening then secure the outside edges of the casing by nailing through the sheetrock
into the wall studs. It may be necessary to use longer finish nails for this step.
b. Continue your installation by nailing up the sides using the same process. Line the side
piece of moulding up with your reveal marks and use a level to keep each side plumb.
Nail through the casing into the jamb of the opening then secure the outside edges of
the casing by nailing through the sheetrock into the wall studs. It may be necessary to
use longer finish nails for this step.
c. Using a nail set, set all the nail heads so they do not protrude past the face of the
moulding.
d. Use wood putty to conceal nail holes and any other irregularities or voids in the
moulding.