Installation Guide

FIBER-CEMENT SIDING
PROFILE 12
KEEP
DRY
!
Step 1
Apply appropriate underlayment to sheathing to prevent the infiltration of wind and moisture. Apply underlay-
ment lapping horizontal joints 2" (51 mm) and vertical joints 6" (152 mm). Only apply enough underlayment
that can be completely covered by siding. In the event this is not possible, do NOT permit water to drain over
uncovered underlayment onto siding.
Step 2
Starting at the bottom, snap a chalk line around the building as a guide line for the top edge of the first
course of siding. Snap succeeding horizontal course lines spacing the lines the necessary distance to
provide the required exposure (See Figure 1).
Step 3
Nail a ¼" x 1½" (6 mm x 38 mm) cant strip along the bottom edge of the sheathing with the
following clearances:
t6" (152 mm) minimum between siding and adjacent finished grade on the exterior
t2" (51 mm) minimum between siding and paths, steps and driveways
t2" (51 mm) minimum between siding and decking materials
t2" (51 mm) minimum between siding and roofing
t1" (25 mm) minimum between siding and gutter and caps
t¼" (6 mm) minimum between siding and horizontal flashing (Do NOT caulk this gap)
Some local building codes may require greater minimum clearances.
Step 4
Start the first and odd-numbered courses at the left corner of the wall with a full siding piece. Make sure
this piece is properly placed, plumbed, leveled, and aligned with the chalk line to assure proper placement of
succeeding courses. Drive nails in pre-drilled holes snug but not too tight. Before driving the last nail at the
right-hand end, insert a backer strip vertically in place and secure it with the last nail (See Figure 1). Always
use a backer strip and place centered at the joint between siding pieces and with its lower end overlapping
the cant strip or the head of the lower course. Continue with full siding pieces. Install adjacent siding butting
tightly together end to end. DO NOT leave spaces between siding pieces.
Step 5
Start the second course and all even-numbered courses with a piece of siding cut in half lengthwise. Align
the head of the siding with the chalk line with the lower edge overlapping the head of the course below to
provide the necessary top-lap between courses. Drive nails in pre-drilled holes snug but not too tight. Install
backer strips at every vertical union as in Step 4. Continue row with full siding pieces. Repeat Steps 4 and 5.
At the top of the wall, measure the height of the last course. Cut the top off pieces for the last course so
they are 1" (25 mm) less than the measured height. Next install a 1" x 3" (25 mm x 76 mm) or 1" x 4"
(25 mm x 102 mm) wood board at the top of the course to cover the cut edge. The 1" (25 mm) gap will allow
the board to be nailed to the subsurface material without nailing into the siding and possibly cause splitting.
Step 6
Apply metal flashing properly at all door and window openings (See Figure 2). In corner treatments, carry the
underlayment felt around the corner of each side wall so there is a double thickness of No.15 asphalt satu-
rated felt over the corner. Use a non-shrinking caulking compound to weather-seal all joints where siding
abuts wooden trim, masonry, or other projections.
PLANNING THE JOB
Determine the location of the bottom edge of the first course. Then determine the total number of courses
to complete one wall based on the nominal exposure. Lay out the job so that top courses under the eaves
will not be wedge-shaped. No siding piece in a course should be less than 6" (152 mm) wide. If less than
6" (152 mm), cut a few inches from adjacent piece.
Figure 1
Figure 2
SHINGLE CUTTER
For rapid, efficient cutting, punching,
and notching, we recommend using a
shingle cutter (available from GAF). Another
method for cutting is scoring and snapping.
A diamond blade saw may also be used.
Caution: Always wear safety glasses and
dust protection when operating power tools.
W eather S ide
™