Estimating in Building Construction

Wood 171

shape (design) are possible. Ducts, piping, and conduit
may be easily incorporated into the trusses. The trusses are
only part of the system and must be used in conjunction
with a deck of some type. Typical truss shapes are shown in
Figure 13.57.

Specifications. Check the type of truss required. If any
particular manufacturer is specified, note how the members
are to be attached (to each other and to the building) and
what stress-grade-marked lumber is required. Note also any
requirements regarding the erection of the trusses and any
finish requirements.

Estimating. The estimator needs to determine the
number, type, and size required. If different sizes are

required, they are kept separate. Any special requirements

for special shapes are noted, with a written proposal from

the manufacturer or supplier. If the estimator is not famil-

iar with the project, arrangements should be made to see

the contract documents for the complete price. A check is

made to see how the truss is attached to the wall or column

supporting it.

If the trusses are to be installed by the general contrac-

tor, an allowance for the required equipment (booms,

cranes) and workers must be made. The type of equipment

and the number of workers will depend on the size and

shape of the truss and the height of erection. Trusses 400

feet long may be placed at the rate of 1,000 to 1,500 sf of

coverage per hour, using two mobile cranes mounted on

trucks and seven workers.

FIGURE 13.57.Typical Wood Truss Shapes.