Table 3-6.-Nominal and Dressed Sizes of Lumber
Figure 3-29.-Laminated lumber.
Laminated lumber (figure 3-29) is made of
several pieces of lumber held together as a single unit,
a process called lamination. Usually 1 1/2-inches
thick, the pieces are nailed, bolted, or glued together
with the grain of all pieces running parallel.
Laminating greatly increases the load-carrying
capacity and rigidity of the weed. When extra length
is needed, the pieces are splicedwith the splices
staggered so that no two adjacent laminations are
spliced at the same point. Built-up beams and girders
are examples. They are built as shown in figure 3-30,
usually nailed or bolted together, and spliced.
Lamination can be used independently or with other
materials in the construction of a structural unit. Trusses
can be made with lamination for the chords and sawed
Figure 3-30.-Built-up beam.