Figure 3-6.-Wood fiber roof decking at gable ends.
ideally suited for built-up roofing, as well as for
asphalt and wood shingles on all types of buildings.
Wood fiber decking is available in four thicknesses:
2 3/8 inches, 1 7/8 inches, 1 3/8 inches, and 15/16 inch.
The standard panels are 2 inches by 8 feet with
tongue-and-groove edges and square ends. The surfaces
are coated on one or both sides at the factory in a variety
INSTALLATION.Wood fiber roof decking is
laid with the tongue-and-groove joint at right angles to
the support members. The decking is started at the cave
line with the groove edge opposite the applicator. Staple
wax paper in position over the rafter before installing
the roof deck. The wax paper protects the exposed
interior finish of the decking if the beams are to be
stained. Caulk the end joints with a nonstaining caulking
compound. Butt the adjacent piece up against the
caulked joint. Drive the tongue-and-groove edges of
each unit firmly together with a wood block cut to fit the
grooved edge of the decking. End joints must be made
over a support member.
NAILING. Although the wood fiber roof panels
have tongue-and-groove edges, they are nailed through
the face into the wood, rafters, or trusses. Face-nail
6 inches OC with 6d nails for 15/16-inch, 8d for
1 3/8-inch, 10d for 1 7/8-inch, and 16d for 2 3/8-inch
If you arent going to apply the finish rooting
material immediately after the roof is sheeted, cover the
deck with building felt paper. The paper will protect the
sheathing in case of rain. Wet panels tend to separate.
Figure 3-7.-Sheathing details at chimney and valley openings.
Roof decking that extends beyond gable-end walls
for the overhang should span not less than three rafter
spaces. This is to ensure anchorage to the railers and to
prevent sagging (see figure 3-6). When the projection is
greater than 16 to 20 inches, special ladder framing is
used to support the sheathing.
Table 3-2.-Determining Roof Area from a Plan