An added layer of critical protection means greater confidence in leakage prevention. Stormtite’s synthetic, non-breathable material effectively sheds water and acts as a vapor retarder — while being flexible enough to install around vents, dormers, and skylights without curling. Stronger than traditional felt, this synthetic underlayment is designed to be resistant to slips, tears, and shredding from foot traffic. Plus, it’s coated top and bottom with tough polyolefin for superior weather resistance. Thanks to built-in UV stabilizers, it can even be exposed up to 30 days and still perform.