What does a perlin support in a building structure?

Perlins are horizontal members used in roof structures, typically in conjunction with rafters or trusses, to provide additional support for the roof load. They are primarily designed to carry the weight of roofing materials, as well as any live loads such as snow or maintenance workers on the roof. By distributing the roof load more effectively, perlins play a critical role in ensuring the overall stability and integrity of the building's roof system.

These elements are often found in metal frame structures or buildings with wide spans, where they help to prevent sagging and structural failure by transferring loads to the vertical components such as columns or walls. Their placement and sizing must be carefully calculated to ensure they can handle the anticipated loads without compromising the safety and performance of the structure.