Asphalt Roof Felt Paper

Asphalt Roofing Felt Paper plays an Integral part in an Effective Roofing System

By Mark J. Donovan

Asphalt roof felt paper is used in roof construction today to aid in water infiltration prevention. Asphalt roof felt paper also acts as a quick solution for providing temporary water protection to the roof. Building codes and shingle manufacturers all require the use of a roof underlayment, such as an asphalt roof felt paper, in the roofing of a home.

Asphalt roof felt paper is available in two common weights, 30 lb and 15 lb weights. These weights correspond to the original weights of the manufactured product, however today’s products do not necessarily have weights that actually correspond to the 30 lb and 15 lb roof felt paper types. Consequently asphalt roofing paper today is commonly referred to as No. 30 and No. 15.

There are advantages and disadvantages with both asphalt roof felt paper weights. No. 30 is thicker and thus less susceptible to tearing. No. 30 roof felt paper, however, is effectively non-breathable.No. 15 roof felt, on the other hand, is somewhat breathable and less expensive. Consequently many roofers use No. 15 weight asphalt roof felt paper.

Besides asphalt based roof felt paper, there are other alternatives today that include ice and water shield barriers, and synthetics. Many roofers will install an ice and water shield on the first 3-6 feet of the roof edge, and then use a traditional asphalt roof felt paper on the upper levels of the roof.

Asphalt roof felt paper is rolled out along the length of the roof and stapled or nailed into place. It is installed similar to installing shingles. The first course is applied near the bottom edge of the roof, followed by an upper course that overlaps the adjacent lower course. The upper levels typically overlap the lower levels by approximately 6 inches.

Notice the asphalt roof felt paper and ice and watershield installed on the roof prior to actually shingling the roof.

Due to the fact that asphalt roof felt paper can tear easily and can be slippery to walk on during hot weather, new synthetic roof underlayments are gaining popularity today. They are more rugged and are less slippery to walk on. They are, however, more expensive than asphalt roof felt paper.

For more help on Shingling Your Home’s Roof, see’s Asphalt Shingle Roofing Bid Sheet. The Asphalt Shingle Roofing Bid Sheet will help to ensure that your roof won’t end up with a blue tarp over it and a dumpster sitting in your yard for weeks as you wait for the roofing contractor to come back and finish roofing your home.

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