Products / CertainTeed FlintBoard CV

Vented roof insulation panel of closed-cell polyisocyanurate, solid wood spacers and a top layer of OSB or plywood, for cross-venting unvented steep-slope roofs. Panels are 4 ft x 8 ft with overall thickness from 2.5 in to 5.0 in, and the wood spacers can be increased to 1.5 in or 2 in for more airflow. CertainTeed lists the foam as meeting ASTM C1289 Type II, Class 1, Grade 2 (20 psi).