Saturated Felt

Saturated felt is defined as an organic or fiberglass mat that has been impregnated with asphalt to create a water-resistant underlayment for use beneath roofing materials. Available in 15-pound and 30-pound weights (per 100 square feet), saturated felt has been used in roofing applications for over 100 years. The 30-pound weight provides greater tear resistance and moisture protection and is required by some building codes as the minimum underlayment for steep-slope roofing applications.