Prosoco R-Guard Cat 5 is part of the family of Prosoco R-Guard products developed to prevent the movement of water and air through building envelopes. Utilize Prosoco R-Guard Cat 5 as the primary air barrier over above grade structural surfaces prepared with R-Guard Joint & Seam Filler and R-Guard FastFlash. Prosoco R-Guard Cat 5 is a single component, Silyl-Terminated-Poly-Ether (STPE) that is roller applied to produce a highly durable, seamless, elastomeric weatherproofing membrane on exterior sheathing, CMU back-up walls, and pre-cast concrete. Proven to prevent water and air penetration of the building envelope in conditions ranging from everyday weather to the drenching rains and 155 mph winds of a Category 5 hurricane. Prosoco R-Guard Cat 5 can be applied in unfavorable weather conditions to dry or damp substrates. This feature eliminates many weather-related construction delays and accelerates the “drying in” of new buildings. The durable, elastomeric membrane adheres to most surfaces, is immediately waterproof and is compatible with most sealants and waterproofing or air barrier components.