Which term describes steel structural members that are protected by spray-on fireproofing or encased in a UL-approved system?

• A. Purlin
• B. Rafter
• C. Protected steel
• D. Truss

Answer: (C)

Steel tends to lose strength as it gets hotter, so protecting it with spray-on fireproofing or encasing it in a listed (UL-approved) fire-resistance system helps keep structural capacity during a fire. When such protection is in place, the term used is protected steel. This label specifically denotes the protective measure applied to the steel, not the basic type or shape of the member.

Purlin, rafter, and truss describe roof framing members by their role or geometry, not whether they have fire protection. They can be protected or unprotected, so they don’t convey the fire-resistance status the term protected steel does.