This material, commonly found at large home improvement retailers, serves as an underlayment in roofing applications. It is a paper sheet saturated with asphalt to provide a water-resistant barrier between roofing shingles and the roof deck. A standard roll covers a specific area, providing a cost-effective layer of protection.
Its significance lies in its ability to shield the roof deck from moisture damage, extending the lifespan of the roof. Historically, it has been a reliable and widely used method for enhancing roof durability and preventing leaks. The weight designation reflects the product’s mass per unit area, influencing its tear resistance and overall performance.