Roof shingles are omnipresent — they’re on just about every house you encounter. You spend a good portion of your life living and sleeping under the protection of asphalt roofing shingles. Did you ever wonder how they work?
Asphalt shingles protect the roofs of most homes in the United States. Although other options exists, such as slate, clay, tiles, metal, or even wood, asphalt shingles have become ubiquitous in the roofing industry because of their relatively low cost, curb appeal, warranties, and because they are simple to maintain.
The design of a basic roofing shingle consists of a substrate or base material saturated with asphalt, an adhesive sealant, and surface granules. The substrate provides most of the strength of the shingle, asphalt contributes the weatherproofing qualities, the sealant reinforces shingles against wind uplift, and surface granules protect the shingle against weather degradation.
The overwhelming majority of modern shingles utilize a woven fiberglass mat as the substrate; in the early decades of asphalt shingle manufacture, cellulose-based materials were used, such as cotton rag felt or pulped wood fibers — and some of these “organic” shingles are still used today. Although they are somewhat stronger than their fiberglass-based counterparts, organic shingles are much more susceptible to fire; the increased flammability is due to the cellulose substrate and the greater quantity of asphalt used in the production of the shingle.
As early as the 1950s and 1960s, substrates of fibrous glass were tested as alternatives to cellulose materials, although the results were not very successful. It wasn’t until the 1970s that Owens Corning Corporation perfected the fiberglass mat substrate that has since become the industry standard.
Asphalt, a by-product of oil refining, is used mostly for road construction and shingle manufacture. Shingles are made with coating-grade asphalt, the quality of which is determined both by its source and by the mineral additives used by the manufacturer. Additives increase the durability of the asphalt; diverse substances have been used over the years, with oyster shells, slate, and mica demonstrating the best qualities of increased asphalt durability.
In the early decades of asphalt shingle use, wind damage was the most frequent cause of shingle failure. The sealant, a strong adhesive compound to hold shingles in place, rectified this problem. The heat of the sun activates the sealant adhesive to form a strong bond between shingles.
Surface granules are the first line of defense in protecting the shingle and extending its useful life span. Granules, usually made from a ceramic material, reflect ultraviolet light and heat from the sun. Were surface granules not present, the effective life of a shingle would be dramatically reduced. Over time, the natural aging of a shingle and normal weathering processes cause surface granules to be lost; the cumulative and combined effects of ultraviolet light, precipitation, temperature cycles, and impacts (such as from hail, tree limbs, wind-blown debris, or the feet of people walking on roofs) eventually cause granule loss. Piles of granules at the exits of downspouts are a sign to homeowners that roof repair or replacement will be needed soon.
J-Conn Roofing & Repair Service, Austin’s professional roofing service, is committed to keeping your shingles in a state of good repair and maximum effectiveness. Whether you need repairs to existing shingles or a complete re-roofing, J-Conn’s skilled roofers and quality roofing materials ensure the long-lasting integrity of your roof. We’ve been serving Austin for more than 30 years. To address all of your roofing needs, give us a call today at 512-479-0510 or contact us on the web for a quote or appointment. Be sure to check our monthly specials for even more savings!