Roof Rafter Framing Details

A collar tie is a horizontal roof rafter compression connector that is located in the uppermost third of the span of a pair of opposed sloped or gable roof rafters.

Roof rafter framing details. Ridge beam sits below the rafters. Span is the horizontal distance between the outside. If you have any two of those values the calculator will quickly figure out the rest of the right triangle which means it will tell you everything else you need to know about a rafter. Definition of collar tie in roof framing definition.

By upper third here we mean one third of the length of the rafter from ridge to top plate. Measure form the top of this line down the board to determine the line length or length of the rafter less the ridge. Position the square at the end of the rafter board with the tongue on your left and facing away from you. Supported by lally columns.

Using a construction calculator. Roof features associated with basic roof framing terms are shown in figure 2 2. In a rafter roof all of these components are required to provide a stable roof. The function of each component is.

Pitch rise run and diagonal. The rafters carry the applied loads to the exterior walls. Rafters act more like the top chord of a roof truss than as a roof joist. The values on the calculator that we use for common roof framing are.

Add the length of the overhang beyond this mark and. Transfers the load of the roof through the raftersto walls below. The point at which all the rafters are attached to. 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.

Refer to the figure as you study the terms discussed in the next paragraphs. Joists and collar ties.