The NRCA has recommended the use of cover boards over plastic foam roof insulation when incorporated into bituminous roof systems for years.
Say you’re a building owner or facility manager and you’ve solicited bids from three roofing contractors for a mechanically attached TPO system. You’ve heard this is the latest thing in roofing — TPO offers great reflectivity for energy savings, and it’s welded at the seams to provide a monolithic membrane once it’s in place.
The contractor you’ve done business with for years — good reputation and trustworthy — is thousands of dollars higher than the low bidder. So when you call him and tell him that, he wonders aloud what system configurations the other guys bid. You look through their bids and find the roof system descriptions: 2-inch polyisocyanurate roof insulation screwed to the steel roof deck and mechanically attached TPO. Your guy asks, “Did they include the insulation cover board?”