Roof Rafter Framing Details

Ridge beam sits below the rafters.

Roof rafter framing details.

Joists and collar ties. Roof features associated with basic roof framing terms are shown in figure 2 2. By upper third here we mean one third of the length of the rafter from ridge to top plate. 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.

Add the length of the overhang beyond this mark and. Roof framing terms are related to the parts of a triangle. Refer to the figure as you study the terms discussed in the next paragraphs. 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.

Rafters act more like the top chord of a roof truss than as a roof joist. 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. Using a construction calculator. Cover some of the more common roof and rafter terms you ll need.

The rafters carry the applied loads to the exterior walls. The point at which all the rafters are attached to. In a rafter roof all of these components are required to provide a stable roof. Supported by lally columns.

Definition of collar tie in roof framing definition. The values on the calculator that we use for common roof framing are. Transfers the load of the roof through the raftersto walls below. Pitch rise run and diagonal.

Position the square at the end of the rafter board with the tongue on your left and facing away from you. Measure form the top of this line down the board to determine the line length or length of the rafter less the ridge.