Asphalt roofing shingles are cost-effective and versatile, which may be why they cover more than 75% of the roofing market. Asphalt shingles are fairly inexpensive, install easily, and are suitable for roof pitches from 4-in-12 to vertical, and are available across a wide range of quality, cost, and style. Easy to cut, fit, and fasten, asphalt shingles are compatible with many different kinds of flashing and edging products, and don’t require specialized accessories for roof edges, wall terminations, and chimney or vent flashings. Asphalt roofing shingles are available in various life span options from 15 to over 40 years. The shingle manufactures will typically sell shingles by weight per bundle. A general rule of thumb is the heavier the bundle, the thicker the shingle, the longer the warranty. Some criticism exists among builders and homeowners as to the true life expectancy of a shingle. It should be mentioned that a 20 year shingle would expect that the roofing shingles would last 20 years under ideal conditions, but unusual temperature, extremes wind, and excessive rain, may shorten the life expectancy of your roofing system.