Which insulation material is not recommended to separate polystyrene and built-up roofing?

Which insulation material is not recommended to separate polystyrene and built-up roofing?

• A. non venting base ply
• B. glass fiberboard insulation
• C. wood fiberboard insulation
• D. perlitic board insulation

Answer: (A)

When separating polystyrene insulation from built-up roofing, you want a layer that can withstand asphalt, prevent chemical interaction with the foam, and allow moisture to dry. Options like glass fiberboard, wood fiberboard, and perlitic board are all insulating boards designed to serve as a separating layer between polystyrene and BUR; they provide a compatible barrier and contribute to the assembly’s stability and fire performance. The non venting base ply is not an insulation board and isn’t intended to act as the separating insulating layer. It’s a BUR base ply, and it doesn’t offer the appropriate moisture management or compatibility with polystyrene and bitumen. That’s why it isn’t recommended for separating polystyrene from built-up roofing.

When separating polystyrene insulation from built-up roofing, you want a layer that can withstand asphalt, prevent chemical interaction with the foam, and allow moisture to dry. Options like glass fiberboard, wood fiberboard, and perlitic board are all insulating boards designed to serve as a separating layer between polystyrene and BUR; they provide a compatible barrier and contribute to the assembly’s stability and fire performance.

The non venting base ply is not an insulation board and isn’t intended to act as the separating insulating layer. It’s a BUR base ply, and it doesn’t offer the appropriate moisture management or compatibility with polystyrene and bitumen. That’s why it isn’t recommended for separating polystyrene from built-up roofing.