Purlins Roof Definition

Purlin plate principal purlin and common purlin.

Purlins roof definition. A horizontal member in the roof. In architecture structural engineering or building a purlin or historically purline purloyne purling perling is a horizontal beam or bar used for structural support in buildings most commonly in a roof. In architecture structural engineering or building a purlin is any longitudinal horizontal structural member in a roof except a type of framing with what is called a crown plate. A traditional purlin strictly by definition is a horizontal structural member in a roof.

Uniformly distributed roof load is carried by purlins. Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern. In the past the majority of roof structures were of wooden construction but over the past 15 to 20 years there has been a vast shift away from wood to metal mainly steel roof construction. Purlins are an important component in a pre engineered steel structural kit.

A horizontal member in a roof. Purlin definition a longitudinal member in a roof frame usually for supporting common rafters or the like between the plate and the ridge. Purlins are connected with panel points of the truss. The purpose of purlins.

These structural supports run perpendicular across the rafter beams. The roof support system is a ridgepole and either rafters which run perpendicular from the top of the walls to the ridge or purlins which run parallel to the ridge. Purlins traditionally support the roof deck cladding sheeting and are in turn supported by the principal rafters steel beams etc. A common arrangement is a rafter and purlin system which combines purlins and rafters.

The roof beams spanning between the trusses are known as purlins. Roof sheets are connected with purlins. Do all roofing projects require purlins. In traditional timber framing there are three basic types of purlin.

There is no direct connection between roof sheathing and truss top chord. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.