TABLE OF CONTENTS The loads and forces required by the IBC (Ref. 3.2) for designing a building were described in Chap. 2. Chapter 3 deals primarily with the transfer of these from one member to another throughout the structure. The distribution of vertical loads in a typical wood-frame building follows the traditional post-and-beam concept. This subject is briefly covered at the beginning of the chapter.
The distribution of lateral forces may not be as evident as the distribution of vertical loads. The majority of Chap. 3 deals with the transfer of lateral forces from the point of origin, through the building, and into the foundation. This subject is introduced by reviewing the three basic types of lateral-force-resisting systems (LFRSs) used in conventional rectangular-type buildings.
Shearwalls and horizontals diaphragms make up the LFRS used in most wood-frame buildings (or buildings with a combination of wood framing and concrete or masonry walls). The chapter concludes with two detailed examples of lateral force calculations for these types of buildings.
The behavior of framing systems (post-and-beam type) under vertical loads is relatively straightforward. Sheathing (decking) spans between the most closely spaced beams; these short-span beams are given various names: stiffeners, rafters, joists, subpurlins. The reactions of these members in turn cause loads on the next set of beams in the framing system; these next beams may be referred to as beams, joists, or purlins. Finally, reactions of the second set of beams impose loads on the largest...
