Figure 1-9.—Post fastened using dowel method.

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 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 post. 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. 1-5