Figure 1-31.Steps in framing a floor opening.
solid blocks should be cut to fit between the joists having
of strength in the area of the opening. You need to frame
a common spacing. The distance between joists is
the opening in a way that restores this strength. The
usually 14 1/2 inches for joists spaced 16 inches OC.
procedure is shown in figure 1-31. Refer to the figure as
Blocking for the odd spaces is cut afterwards.
you study the following steps:
Framing Floor Openings
1. Measure and mark the positions of the trimmers
Floor openings, where stairs rise to the floor or large
on the outside wall and interior wall or girder.
duct work passes through, require special framing.
2. Position and fasten the inside trimmers and mark
When the joists are cut for such openings, there is a loss
the position of the double headers.