15 Or 30 Roofing Felt

For many years roofers used asphalt saturated felt under roofing shingles and it was historically available in two standard weights.

15 or 30 roofing felt.

Felt roof deck protection. The type i recommend depends on roof slope. We use the 30 felt paper because i feel it is the best product for your roof. 15 pounds per hundred square feet and 30 pounds per hundred square feet.

This felt will help prevent damage to your roof from wind driven rain and water from other sources. Item 656632 model 0903000. Heavier shingles may help to keep felt from pushing up but then again maybe they won t. The best weight for roofing felt is the 30 pound product because it provides thicker and stronger.

Gaf shingle mate 36 in x 144 ft 400 sq ft felt roof underlayment. For slopes less than 4 12 i recommend 2 layers of 15. 15 is easy to rip underfoot when installing the new roof system and ripped felt paper is useless regardless of weight. Plywood or osb roof deck so 15 20 or 30 will work for any shingle roof.

Problem is the felt doesn t flatten out even when it dries so the ridges don t go away. No 15 felt and no. It is thicker and heavier than the alternative 15 so if water ever gets under your shingles it has to work extra hard to get through the felt. In my opinion felt paper is a vapor barrier plus keeps the oils in the shingles from leaching out and into the wood substrate i e.

30 was used as a base sheet for built up roofing and underlayment under slate tile and shingles. One roofing square and 30 lb felt paper weighed 30 pounds per square. Add an extra layer of protection between your shingles and roof deck with this 30 216 sq. Weight matters asphalt saturated heavy duty roofing felt is available in 15 and 30 pound weights.

15 lb felt paper weighed 15 pounds per 100 sq. When the vapor hits the roofing felt the felt expands which in turn pushes up the shingles. Helps reduce the possibility of leaks. 15 came perforated for use as a ply sheet for built up roofing use and non perforated.

Felt roofing underlayment is typically available in two types. Felt paper is commonly produced with a certain number of recycled products and coated with asphalt. In the old days common felt was 15 lb felt and 30 lb felt and a roll of the first held 4 squares and weighed 60 lbs while a roll of the second held 2 squares and weighed 60 lbs. The 15 pound was for lighter weight projects while the 30 offered more heavy duty protection.