If you encounter white powder while cutting a roof, what type of roof is it likely to be?

When encountering white powder while cutting a roof, it is likely indicative of a gypsum roof. Gypsum roofs, often used in commercial construction, typically consist of a layer of gypsum board or assembly and can produce a white powder when cut or disturbed. This powder is the result of the material’s composition, which includes gypsum, a mineral that appears white and can create a dust-like residue during the cutting process.

In contrast, wood shake roofs consist of shingles made from cedar or other types of wood, which do not produce white powder when cut. Composite roofs, generally made from asphalt or synthetic materials, also do not release a white powder but instead might produce shavings or granules indicative of their composition. Metal roofs, being made of various metals like steel or aluminum, do not generate any powder upon cutting but may produce metal shavings. Therefore, the presence of white powder is a strong indicator that you are dealing with a gypsum roof, making this the correct answer.