Asphalt Shingles

Asphalt shingles are composed of: a base material, either organic felt or glass-fiber mat, that provides support for the weather-resistant components and gives a shingle strength; asphalt and fillers; and surfacing material, generally in the form of mineral granules, that provides protection from impact and UV degradation and improves fire resistance.

Shingles may be produced in a single layer or two or more layers. The latter generally are known as laminated strip shingles, or architectural shingles, and they have a three dimensional appearance.

Both 3-tab asphalt shingles and laminated asphalt shingles contain a strip of factory applied adhesive that is activated by the sun’s heat after installation and seals each shingle to the next course. The seal strip also provides much of a shingle’s resistance to wind uplift. Shingles with factory-applied adhesive have a strip of clear polyester film applied to each shingle to prevent the sealing strips from bonding the shingles together when packaged. When the shingles are installed, the self-sealing strips will not align with the plastic film strips and will bond to adjacent shingles. For this reason, the plastic film strips do not have to be removed.

NRCA does not make any recommendations about which shingle product or manufacturer to use; however, NRCA does recommend asphalt shingles meet standards established by ASTM International.

  • Organic asphalt shingles should meet ASTM D225, “Standard Specification for Asphalt Shingles (Organic Felt) Surfaced With Mineral Granules.”
  • Fiberglass asphalt shingles should meet ASTM D3462, “Standard Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules.”

In locations where the average temperature for January is 30° F or less, NRCA suggests installation of an ice-dam protection membrane. An ice-dam protection membrane generally is a self-adhering polymer-modified bitumen membrane.

An ice dam protection membrane should be applied starting at a roof’s eaves and extending upslope a minimum of 24 inches from the exterior wall line of a building. For slopes less than 4:12 (18 degrees), NRCA recommends a minimum of 36 inches.