Which building element found in Type V construction is likely to produce dense, dark, oily toxic smoke when it burns?

Which building element found in Type V construction is likely to produce dense, dark, oily toxic smoke when it burns?

• A. Vinyl siding
• B. Industrial glue
• C. Exterior wall cavities
• D. Prefabricated wood truss system

Answer: (A)

In Type V, light wood-frame buildings often use exterior finishes like vinyl siding. Vinyl siding is made from PVC, and when it burns it decomposes to produce dense, dark, oily smoke along with toxic gases such as hydrogen chloride. That characteristic oily, heavy smoke is a hallmark of burning vinyl, making it the most likely element to create that type of smoke. The other options—industrial glue, exterior wall cavities, and a prefabricated wood truss system—don’t consistently produce that same dense, dark, oily smoke signature as burning PVC does.