WeatherLock® Mat Waterproofing Underlayment provides superior roof deck protection for your home. It helps prevent damage caused by freeze/thaw cycling, wind-driven rains, and normal water flow that occurs around valleys, vents, chimneys and skylights.

Its patented mat-faced design provides a consistent surface, reducing slipping, sticking and scuffing. It is 40% lighter than competitive products, making it easier to load, carry and install.

Engineered for asphalt shingles, wood shakes, and quarry slate roof assemblies. It's an essential part of a complete roofing system.