CertainTeed's FlintBoard® ISO HD is a high-density polyisocyanurate roof insulation board designed for use as a coverboard in low-slope roofing systems. This roofing material provides reduced labor and superior thermal performance over traditional wood fiber and gypsum-based coverboards while also delivering excellent compressive strength and an SH-1 hail rating. FlintBoard® ISO HD is made with a high-density polyisocyanurate foam core, bonded to a glass-reinforced facer on both sides, which gives the insulation superior strength and durability. The facer is also designed to provide a smooth, uniform surface for the installation of the roof membrane. A core function to any coverboard, FlintBoard® ISO HD is engineered to resist compressive forces, protecting the roof system from effects of hail, roof top construction traffic and other potentially damaging elements. FlintBoard® ISO HD is also engineered to be fire-resistant. HD achieves a UL 790 Class A combustible deck assembly...See More rating at 1⁄2" thickness without the use of a fire-rated slip sheet or the presence of a fire barrier. The high-density foam core is resistant to moisture, mold, and mildew, which helps to extend the life of the roofing system. Another advantage of FlintBoard® ISO HD is its ease of installation. Lightweight, easy to cut, easy to handle, HD can be adhered or mechanically attached. Reach out to your local CertainTeed Territory Manager to request a sample and demonstration of FlintBoard® ISO HD. See Less