The first case is when the ceiling joists are oriented perpendicular to the rafters or are on a different spacing than the rafters. However, there are a couple of cases where the bottom leg of the triangles (the ceiling joists) might not be present or might not connect rafters together.
#RAFTER FRAMING CODE#
That’s why the ridge board is nonstructural and is allowed by the code to consist of 1x lumber. (See illustration.)īecause of this triangle shape, the connection of rafters to the ridge board is easy because all the weight of the roof is assumed to transfer down to the bearing at the top plate.
Most importantly, the bottom of each triangle (the ceiling joists), must be fastened securely to the rafters on each end and must continue across the entire width of the ceiling so they keep the ends of the rafters from spreading out when loaded.
#RAFTER FRAMING HOW TO#
In order to maintain the triangle shape, there are specific requirements for how to fasten the corners of the triangle together. Meeting current IRC roof framing requirements means builders are really constructing very simple triangles using the rafters and ceiling joists, because triangles are known to be the most stable shape. Whether it’s because of the growing size of houses, or because roofs are getting more complicated, the code requirements for stick-framing roofs have become more complex over the years. For example, in Texas, where stick framing is common, there are entire crews specializing only in framing roofs. However, constructing a stick-framed roof is not always easy. Builders sometimes also prefer this construction method when they want to provide a large attic space or high, vaulted ceilings (often called cathedral ceilings). One of the most common is that with a site-built roof, it’s easier to customize the roofline. While truss roofs are the most popular construction style today - by some estimates, truss roofs outnumber stick-frame roofs two to one- there are regions of the country where builders still prefer stick-frame roofing. There are two common ways of framing the roof of a house: with pre-manufactured trusses, or with rafters and ceiling joists, commonly called stick framing. The post will also discuss some changes in the 2021 IRC that affect construction of stick-frame roofs. In this post, Randy Shackelford discusses some design choices available to stick-frame builders, the challenges they pose, and the solutions offered by the Simpson Strong-Tie® connector system for stick-frame roofing. Although truss-designed roofs are predominant throughout most of the residential construction industry, there are regions where building with stick-frame roofs is still common.
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