For installation of which roofing system is a 25 lbs application of asphalt bitumen specifically required?

The installation of a built-up roofing system specifically requires a 25 lbs application of asphalt bitumen to create the multiple layers that define this roofing method. Built-up roofing involves layering asphalt and reinforcing fabrics to develop a durable, weather-resistant surface. The use of this amount of asphalt bitumen is part of what provides the appropriate adhesion and strength required for the roofing system.

In this context, the asphalt bitumen acts as both an adhesive and a waterproofing agent, ensuring that the layers bond effectively and that the entire system can withstand the environmental stresses it may encounter. The specification of a 25 lbs application reflects industry standards for achieving optimal performance and longevity of the roofing system.

Other roofing systems, such as modified bitumen, single-ply membranes, and asphalt shingles, have different installation requirements and methods. For example, modified bitumen typically utilizes rolls with an adhesive bond, single-ply membranes rely on mechanical fasteners or adhesive for installation, and asphalt shingles are designed to be installed in a straightforward overlapping pattern without the same bitumen application requirement needed for built-up roofing.