Figure 1-9.Post fastened using dowel method.
Figure 1-10.Metal base plates for wood posts.
dimensions and locations are shown on the foundation
plan. When required, posts give central support to the
long span of girders. Also, girders can be used to support
other girders. There should be at least 18 inches
clearance between the bottoms of the floor joists and the
ground and at least 12 inches between the bottom of the
girder and the ground (fig. 1-8).
Wood posts are placed directly below wood girders.
As a general rule, the width of the wood post should be
equal to the width of the girder it supports. For example,
a 4-inch-wide girder requires a 4- by 4- or 4- by 6-inch
A wood post can be secured to a concrete pillar in
several ways. The post can be nailed to a pier block
secured to the top of a concrete pier; it can be placed
over a previously inserted 1/2-inch steel dowel in the
concrete; or, it can be placed into a metal base set into
the concrete pier at the time of the pour. When using
the dowel method, make sure the dowel extends at least
3 inches into the concrete and the post, as shown in
figure 1-9. A metal base embedded in the concrete
(fig. 1-10) is the preferred method since nothing else is
needed to secure the base.
As with the bottom of the post, the top must also be
secured to the girder. This can be done using angle iron
brackets or metal plates. Figure 1-11 shows two metal
post caps used with posts and girders, either nailed or
bolted to the girders.
Figure 1-11.Metal post caps.