Roof Joist Framing Construction Details

In addition to floor and roof framing details this guide includes recommendations for cantilevers and placement of web holes.

Roof joist framing construction details.

End bearing in hanger supported by a beam. Here we have a wood framed gable roof. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. Load bearing or primary structure usually constructed in timber in a residential construction.

End bearing in hanger on a top plate. In order to maintain the triangle shape there are specific requirements for how to fasten the corners of the triangle together. End bearing with rim board. Continuing on from part 3.

I joists in floor and roof applications. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Not shown are the hip and valley rafters needed to tie the roof together where the rafters are framed at an angle to each other. Prescriptive roof consisting of the rafters a ridge board ceiling joists and collar ties.

Good installation begins with specification of the correct joist for the application. Intermediate bearing with blocking panels. I joist construction details. Let s consider a basic gable wood roof framing design.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. 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. The construction of the flat roof is similar to that of the timber upper floor. End bearing with blocking panels.

In a rafter roof all of these components are required to provide a stable roof.