Board construction and protection
DensDeck Prime Roof Board has a gypsum core with fibreglass mat facings on both sides. According to Roofing Today, the core is made specifically for exterior roofing applications, while the facings contribute to the board’s strength and resistance to impact and fire exposure.
The report describes gypsum as a mineral used in building products for its natural fire resistance and dimensional stability. It says the core helps the board retain its dimensions and provides structural stability within the roof assembly.
The board is also claimed to increase the force needed to puncture the waterproofing compared with an assembly without a cover board. Roofing Today does not give a numerical result for that comparison.
Testing and approval claims
Roofing Today says DensDeck Prime features in more than 200,000 Factory Mutual (FM) Approved roof assemblies, with configurations tested to FM4470. The report also says the product has been sold in the US with FM Approval and UL classification for nearly 40 years.
The article describes the board as A1 classified and non-combustible. Its fire-performance references include ANSI/UL 790, EN 13501-1 and ASTM E136. It also reports testing intended to support fire resistance over both combustible and non-combustible decks.
Bonding and roof system design
For installation, Roofing Today reports compatibility with a range of roofing adhesives. It says a primer is not needed in many cases when adhesive is applied directly to the coated face. The article leaves assessment of suitability for direct bonding or torching to the roof system designer.
The product is presented for use in commercial flat roof assemblies, including those designed to carry building-applied photovoltaic (BAPV) installations. Roofing Today says the cover board can support the additional performance demands associated with these rooftop solar systems, alongside its stated compressive strength and durability benefits.