At least how many weights of polymer-modified bitumen base sheets are common?

At least how many weights of polymer-modified bitumen base sheets are common?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (B)

In polymer-modified bitumen roofing, base sheets are manufactured in several thicknesses (weights) to suit different substrates, handling needs, and performance requirements. The common practice is to stock three main weights: a lighter sheet for easier handling and lower cost, a medium sheet for general use, and a heavier sheet for higher tear and puncture resistance and better wind uplift performance. Because these three categories cover typical installation scenarios, at least three weights are commonly available. While some brands offer additional options, three standard weights are the norm in most projects.

In polymer-modified bitumen roofing, base sheets are manufactured in several thicknesses (weights) to suit different substrates, handling needs, and performance requirements. The common practice is to stock three main weights: a lighter sheet for easier handling and lower cost, a medium sheet for general use, and a heavier sheet for higher tear and puncture resistance and better wind uplift performance. Because these three categories cover typical installation scenarios, at least three weights are commonly available. While some brands offer additional options, three standard weights are the norm in most projects.