RAFTER AND ROOF COMPONENT PARTS Presentation 19: RAFTER AND ROOF COMPONENT PARTS

Gable Roof A gable roof is the more common roof style.

Made with gable rafters, which are all the same. Gable Roof A symmetrical triangular shape. These rafters are referred to as COMMON rafters. Made with gable rafters, which are all the same.

Roof Framing Terms Terms relating to roof framing include … Span is usually the width of the building. Span

Roof Framing Terms Rise is the total increase in rafter elevation. Run is the horizontal distance under a rafter. Rise Run Span In this case it is one-half the span.

Rafter Parts Ridge Rafter Rafter Tail

Ridge Cut Ridge Plumb Line

Bird’s Mouth and Tail Bird’s Mouth or Seat Cut

Bird’s Mouth and Tail Bird’s Mouth Plumb Line Tail or Fascia Plumb Line Bird’s Mouth Level Line Tail or Soffit Level Line

Projection vs. Overhang Always sloping Overhang Projection Always horizontal

Rafter Parts Rafter or Line Length - from the ridge plumb line to bird’s mouth plumb line.

Rafter Parts Unit Triangle U Unit Rise Total Rise Unit Triangle Has three parts just like the house. Found on the plans and similar to Total Rise.

Rafter Parts Unit Run U Unit Length Line Length U Unit Length Equal to 12″ and similar to Total Run Similar to Line Length Total Run

Conclusions Gable rafters are called common rafters. Rafters have many component names. Rise, run, and length are terms used to define parts of a rafter. Unit triangle is similar to the house triangle.