Cot PEHD Rainplus 32/88° Cot PEHD Rainplus 32/88° is a polyethylene (PE) high-density (HD) roofing membrane designed for use in low-slope roofing applications. It has a 32 mil (0.81 mm) thick base layer and a 88 mil (2.2 mm) thick topcoat layer. The membrane is designed to provide superior resistance to water, wind and fire, as well as excellent durability and flexibility for long-term performance. It features a granular slip-resistant surface to help reduce the risk of slipping when walking on the roof.