All of the following roofing material can be re-used except:

• A. Clay tile
• B. Metal roofing
• C. Cement tile
• D. Aggregate materials

Answer: (D)

The main idea is whether roofing materials can be salvaged and re-used when a roof is replaced. Clay tile, metal roofing, and cement tile are designed as durable, modular coverings that can often be lifted, inspected, and reinstalled on a new or same roof if they’re in good condition. With careful removal, these materials can remain functional and continue to protect the structure, which is why they’re commonly reusable.

Aggregate materials, like ballast used to hold down some flat roof membranes, aren’t actual roof coverings. They don’t form the weatherproof layer, and once you remove them they don’t provide a reusable roofing surface. They’re typically cleared away and replaced or repurposed for other uses, not reinstalled as a roof. That’s why aggregate materials are the exception.