The WeatherLock Underlayment provides waterproofing protection and helps prevent water infiltration. Since most tile and metal roofing is water-shedding, not waterproofing, help protect your roof with WeatherLock® Specialty Tile & Metal underlayment. Unlike felt underlayment, WeatherLock® Specialty Tile & Metal underlayment will not melt or tear when exposed to moisture, severe heat or cold weather.