A disadvantage of metal roofs to firefighters is that they can be sharp.

• A. May be built over existing roof
• B. Lightweight
• C. Sharp
• D. Non combustible

Answer: (C)

The key idea is that metal roofs introduce a specific safety hazard for firefighters: sharp edges and exposed seams can cause cuts and lacerations during operations like ventilation, roof access, or cutting through the roof. While metal roofs have advantages—being noncombustible and often lighter than other roofing materials, which can reduce collapse risk and slow fire spread—these benefits don’t address injuries from sharp edges. The statement about sharpness directly describes a danger firefighters face on metal roofs, making it the best choice. The other statements describe aspects that are not disadvantages to firefighters (or are more about construction practices), such as being potentially built over existing roofs, being lightweight, or being noncombustible.