TYPAR is a polypropylene nonwoven breathable weather membrane. Its technologically-advanced design reduces the risk of moisture damage in the wall cavity unlike any other product on the market, and the facts support it. TYPAR delivers the best balance of water holdout and breathability. TYPAR’s tear strength is 4 times that of Tyvek’s. Tyvek has poor surfactant resistance. TYPAR holds up better over time. TYPAR’s UV exposure rating is 50% longer than Tyvek’s.