Rafter And Purlin Roof Construction

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.

Rafter and purlin roof construction.

R802 1 5 8 exposure to weather. Purlins shall be sized not less than the required size of the rafters that they support. In steel construction the term purlin typically refers to roof framing members that span parallel to the building eave and support the roof decking or sheeting. Metal c purlins are light in weight and perfect for simple span construction.

Metal building roof purlins provide three structural functions. Secondly purlins tie the rafters together stabilizing and strengthening the structure s rigid framing. 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. Exposed rafters are a feature of some traditional roof styles.

There are two basic methods of pitched roof construction. First the purlins support the roof. Purlins shall be continuous and shall be supported by 2 inch by 4 inch 51 mm by 102 mm. A cut roof this is the traditional method of cutting the timber on site and building up the roof using rafters ridge boards joists and purlins etc the exact details being determined by the size of roof size of timbers etc.

The roof framing modification factors shall take into consideration the climatological location. Thirdly purlins add additional support between the spans of the individual framing bays. The steel purlins are in turn supported by rafters or walls. The rafters then hold up battens which hold the roof fabric typically tiles or steel sheeting.

Civil engineering design in architecture or structural engineering or building a purlin or purline is a horizontal structural member in a roof. A common arrangement is a rafter and purlin system which combines purlins and rafters.