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Builder 3&2 Volume 02 - Construction manual for building structures | Next
Bracing |
Figure 1-35.—Rough frame openings for doors and windows.
trimmer studs, and, in some cases, top cripple studs. The
rough opening for a typical window includes the same
members as for a dear, plus a rough window sill and
bottom cripples.
A header is placed at the top of a rough opening. It
must be strong enough to carry the weight bearing down
on that section of the wall. The header is supported by
trimmer studs fitting between the soleplate and the
bottom of the header. The trimmer studs are nailed into
the regular studs at each side of the header. Nails are also
driven through the regular studs into the ends of the
header.
The header maybe either solid or built up of two 2
by 4 pieces with a 1/2-inch spacer. The spacer is needed
to bring the width of the header to 3 1/2 inches. This is
the actual width of a nominal 2 by 4 stud wall. A built-up
header is as strong as or stronger than a solid piece.
The type and size of header is shown in the
blueprints. Header size is determined by the width of the
opening and by how much weight is bearing down from
the floor above.
The tops of all door and window openings in all
walls are usually in line with each other. Therefore, all
headers are usually the same height from the floor. The
standard height of walls in most wind-framed buildings
is either 8 feet 3/4 inch or 8 feet 1 inch from the subfloor
to the ceiling joists. The standard height of the doors is
6 feet 8 inches.
Cripple studs are nailed between the header and the
double top plate of a door opening. These help carry the
weight from the top plate to the header. The cripple studs
are generally spaced 16 inches OC.
A rough window sill is added to the bottom of a
rough window opening. The sill provides support for the
finished window and frame to be placed in the wall. The
distance between the sill and the header is determined
by the dimensions of the window, the window frame,
and the necessary clearances at the top and bottom of
the frame. Cripple studs, spaced 16 inches OC, are
1-19
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