Conventional roof assemblies make up the majority of low-slope roof assemblies in North America. The design of these roof assemblies typically considers a variety of factors including product availability, economics, aesthetics, energy consumption, building type, local industry familiarity, and compliance with building codes and green building programs; however, the implications of these selections are often not fully understood. Factors including membrane colour and insulation type can have significant impacts on the thermal performance of the roof assembly and consequently on building energy consumption, occupant comfort, membrane durability, and assembly service life.

This research study analyzes the performance of nine different roof assemblies with different membrane colour (white, grey, and black) and insulation arrangements (polyisocyanurate, stone wool, and hybrid) with respect to energy transfer and membrane durability. This assessment includes consideration of insulation thermal mass, insulation age, insulation dimensional stability, latent heat transfer, roof membrane reflectance, roof membrane soiling, and roof membrane temperatures.

Prepared by RDH for Roxul and Soprema.

RDH Building Science