Synthetic Underlayment

Synthetic underlayment is defined as a woven or non-woven polypropylene or polyethylene sheet material installed over the roof deck as a secondary moisture barrier beneath the shingles. Synthetic underlayment has largely replaced traditional felt underlayment due to its superior tear strength (up to 10x stronger), UV resistance (up to 6 months of exposure), lighter weight, and lay-flat characteristics. Products like Owens Corning ProArmor provide a non-slip walking surface and cover approximately 10 squares (1,000 sq ft) per roll.