What’s the Asphalt Shingle Roofing System Components?
There’s much more to a roof’s protection than just asphalt shingles. — They’re a part of an entire system designed to optimize roof performance and durability.
While managing your roofing project with contractors, ask them about the entire package of products they use to protect homes.
– Roofing paper (felt paper/tar paper): Most roofing paper is asphalt-saturated felt or a synthetic rubber-like material. It’s produced in rolls 36” to 48” wide, is laid horizontally on the roof decked and stapled, starting at the roof eave. The next layer is overlapped based on the slope of the roof—the greater the pitch, the less overlap is required. The purpose of the product is to protect the roof deck against moisture blown under the shingles (and as a last line of defense against leaks).
– Drip edge: This is a strip of aluminum formed to fit over the eave edges. About 1.5” to 2” wide, the drip edge extends out from the eaves to direct water running off the roof into the gutters rather than allowing it to wet the fascia.
– Starter shingles/strip: Typically 12”-14” wide, a row of starter shingles is installed horizontally at the eaves to provide an extra measure of protection where ice dams and windblown moisture pose a threat to the roof. The shingles are fiberglass mat saturated with asphalt. Starter strip might also be installed at the roof rake – the outer edge of a gable roof that runs from the eave to the peak.
– Rolled water barrier: This asphalt-based or synthetic rolled roofing is applied in valleys for extra protection because of the large volume of water that passes through them.
– Ridge vents: These are raised plastic vents about 12” wide and 48” long. Ridge vents are installed on peaks where there should be a slight gap in the roof deck that allows heat to escape the attic.
– Shingles: The shingles are installed over the paper and starter strip, starting at the eaves and going up row-by-row in a staggered manner. Each row overlaps the one beneath it by half or slightly more to produce multiple layers of protection.
– Ridge cap shingles/hip shingles: These specialty shingles cover the ridge vents, unvented ridges, and hips.