In BUR systems, what is the function of the interply layer?

The interply layer in Built-Up Roofing (BUR) systems serves the crucial function of providing structural strength to the roofing system. This layer consists of a series of felts or mats that are layered and bonded together with bitumen. By incorporating the interply layer, the overall integrity and durability of the roof are enhanced, helping to withstand various stresses such as thermal expansion, weight from environmental factors like snow, and impacts from debris.

This contribution to structural strength ensures that the roof can endure long-term exposure to the elements, maintain its form, and prevent potential failures. The interply layer acts as a reinforcement element, crucial for the performance of the entire roofing system. While insulation barriers and aesthetic qualities are important in roofing systems, and water management is vital for preventing leaks, the primary role of the interply layer centers around adding strength and stability to withstand a variety of stressors.