Purlin Roof Framing Diagram

Component w sinθ in the plane of the sheathing.

Purlin roof framing diagram. About the base of the purlin based on the free body diagram shown in figure 3. Component w cosθ perpendicular to the plane of the sheathing and a downslope. In architecture structural engineering or building a purlin or historically purline purloyne purling perling is any longitudinal horizontal structural member in a roof except a type of framing with what is called a crown plate. This article and series of illustrated diagrams shows you all the parts of a basic roof truss king truss and queen truss.

For a sloped roof the components of the gravity load are divided into a normal. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and or the building walls steel beams etc. The roof truss structure and design is integral to roof structural integrity and shape. There are many types of roof trusses as wall as many types of roofs more types than there are parts.

Also referred to as secondary structurals this type of framing runs in between primary framing elements creating a structure within a structure much like cross beams in a wooden building. In architecture or structural engineering or building a purlin or purline is a horizontal structural member in a roof.