Purlins are horizontal beams used in construction, primarily to support roofing materials. They are typically made of steel or wood and are installed parallel to the roof slope. Purlins help distribute the weight of the roof and provide a framework for attaching roofing sheets or panels. In addition to supporting roofs, purlins can also enhance the structural integrity of buildings. They are commonly found in commercial and industrial structures, such as warehouses and factories, where large spans are needed. Proper installation of purlins is essential for ensuring the durability and safety of the overall structure.