Purlin (Gp/ms)

A purlin is a horizontal structural member used in a roof to support the roof deck or sheeting. Purlins carry loads from the roof (such as dead weight and snow) and transfer them to the main structural elements like rafters or walls. They are essential for providing a framework for the roof's surface, which can be made of wood, metal, or other materials. Steel purlins are common, though traditional wooden ones exist.

Provide a frame for the roof surface: 
Without purlins, there would be no framework for the roof's surface material to rest on. 

Transfer loads: 
They efficiently distribute the roof's weight to the main structural members of the building, such as trusses, rafters, or walls. 

Support the roof load: 
Purlins support the weight of the roof sheeting, panels, and any additional loads like snow or rainwater, transferring the load to the rafters or walls.