Products / Purlin Vent

Purlin Vent is a fluted, crush-resistant polypropylene sheet that Cor-A-Vent places between a metal roof or siding and the purlins or girts of a metal building, to ventilate the cold side of the insulation and act as a thermal break. The product page gives an R-value of 3.1, 40 square inches of net free vent area per 4-foot section, cross ventilation both horizontally and vertically, and a crush test in which one square foot of the 6-ply board passed up to 7,653 lbs at an independent agency, and says it pairs with Cor-A-Vent's metal-roof ridge vents and with Roof Hugger on metal re-roofs. It ships as twelve 4-foot pieces per 13 lb unit.