Estimating in Building Construction

150 CHAPTER THIRTEEN

FIGURE 13.11.Joist/Girder Details. 

Trimmers and Headers. Openings in the floor, such as
for stairs or fireplaces, are framed with trimmers running in
the direction of the joists and headers which support the
cut-off “tail beams” of the joist (Figure 13.12).
Unless the specifications say otherwise, when the
header length (Figure 13.13) is 4 feet or less, most codes

allow single trimmers and headers to be used. For header

lengths greater than 4 feet, codes usually require double

trimmers and headers (Figure 13.14), and under special

conditions some codes even require them to be tripled.

FIGURE 13.12.Framing for Floor Openings.

FIGURE 13.10.Joist Dimensions.