Figure 30. Prefabricated wooden frame building.
subfloor is laid either diagonally or perpendicular to the
The plywood may be placed either horizontally or
joists. The finish floor, if one is used, is laid lengthwise
vertically on the sidewall. Sheets placed horizontally help
in the building. This type of building may also be used
to brace the corners. Knee braces (see fig. 30) in end
with a concrete slab floor.
sections extend from the top plate at a corner to the
4-18. Repairs to the floor consist of replacing
bottom plate at the door opening. Set-in bracing (short
individual pieces of flooring. Recovering with a layer of
lengths of 2x4's nailed between the studs at an angle) may
plywood may also be justified if the walls and roof are in
be used in the sidewalls. Corner braces (see fig. 30)
good condition and the building can be used for several
extend across a corner, from top plate to top plate, to hold
more years. Use a layer of 15-pound felt between the
the corner square.
layers of flooring to prevent dust from entering through
4-20. The exterior wall covering may be 1-inch
the joints. Tile and linoleum are not used on wood floors
sheathing, fiberboard and insulation panels, or plywood.
if the floor is not reasonably solid and covered with a
Rigid insulation boards may be installed as a first
covering, followed by a felt membrane, a layer of
4-19. Walls. The walls in the framed prefab consist of
plywood, and a layer of roofing felt. The roofing felt
studs, plates, girts, and braces. The sidewalls have studs
protects the exterior wall from moisture and eliminates
spaced 4 feet on-center and the end walls have studs at the
the need for painting. Thin wooden strips or wood lathe
corner and beside the door opening. Single top and
are used to hold the roofing felt in place.
bottom plates are used on the ends of the studs. The
4-21. Your work on the exterior walls consists of
bottom, or sole plate, is placed on top of the subfloor and
adding additional bracing, repairing windows and doors,
is fastened to the subfloor and joists as in platform
and replacing sheathing and felt. Torn felt should be
construction. The girt is a horizontal member located at
replaced and fastened with wood strips. Check the wood
about the center height of the wall. It serves as a
strips that hold the felt covering in place. Draw loose
fastening surface for exterior wall coverings. Notice the
nails up tight to hold the strips firmly against the felt.
4-22. Roof. The roof consists of precut rafters, ceiling
horizontal gins in the end section in figure 30. These girts
serve as a fastening surface for 4x8-foot sheets of
joists, and braces that can be assembled on the job to
plywood that are place horizontally.
make a truss. The ceiling joist extends the full width of
the building and