Sustainability and energy efficiency are buzz words in the roofing industry. Highly reflective roof systems, vegetative coverings and roof-mounted photovoltaic systems are in the headlines every day. Although these sustainable and energy-efficient features are valid, they should be secondary to a properly installed insulation layer within a roof system.
NRCA continues to recommend proper design and installation of an insulation layer because an underinsulated building envelope is not energy-efficient. And from a building owner's perspective, installing high R-value roof insulation should be a priority for energy efficiency at the roof level. The roofing industry should continue to promote insulation and energy efficiency, as well as traditional methods of weatherproofing.
A proper design for an insulation layer is two or more layers of insulation with staggered and offset joints and a cover board layer to separate the primary thermal insulation layer from the membrane. Mechanical fasteners only should be used to secure the bottom layer(s) of insulation, not the top layer.
Benefits of proper design