Which type of roofing is characterized by layers of felt and asphalt?

Built-up roofing is characterized by layers of felt and asphalt, which are combined to create a durable, watertight roofing system. This method, often abbreviated as BUR, involves alternating layers of roofing felt and bitumen (asphalt), which are applied in several layers. The result is a thick, insulated membrane that effectively protects the underlying structure from moisture infiltration and harsh weather conditions.

The construction technique of built-up roofing allows for enhanced durability and can provide excellent thermal performance. Additionally, the multiple layers contribute to its ability to withstand various stresses and impacts that a roof may encounter over its lifespan. It can be topped with a protective gravel layer or a reflective coating to increase energy efficiency and extend the life of the roofing system.

Understanding built-up roofing's composition and benefits is crucial for recognizing its use in commercial and industrial applications, where longevity and weather resistance are paramount. This distinct layer construction sets it apart from other types like single-ply, tile, or metal roofing, which do not utilize this layered felt and asphalt method in the same way.