Roofs are not only one of the most important systems for a building’s durability and
performance, they’re a cornerstone of the way a home looks. Choose the right product
and install it well, and the roof can provide many years of beautiful, low-maintenance
protection.
Material selection depends on many variables that contractors must be familiar with to make good recommendations. “It all depends on the pitch of the roof, the aesthetics of the home and the conditions that we find in the neighborhood,” says Dan Rheaume, owner of
Raynproof Roofing in Seattle. “You’re not going to use the same material on a high-end
home in the suburbs as on a tract home in the city.”
Check the CodeCheck your local building code before buying shingles. “Contractors need to make sure that the shingles they buy meet building code, because it’s not illegal to manufacture a product that doesn’t meet building code, but it’s illegal to install it,” says James Kirby, architect and assistant executive director of technical communications for the National Roofing Contractors Association.
Shingle TypesRoof shingles may be made of asphalt, fiber-cement, clay, concrete, wood or slate.
Asphalt shingles are the most common roofing material in the United States, and the
most cost-effective. Asphalt shingles have three components: reinforcing material (usually fiberglass or organic material soaked in asphalt to create a waterproof barrier); asphalt laminate; and granules (usually ceramic).
Asphalt shingles come in varying thickness and designs, from standard flat-strip shingles to laminated or architectural shingles that mimic the look and feel of traditional shingles.
Asphalt shingles and have a base of either fiberglass or organic material. Fiberglass-based asphalt shingles have a higher fire rating than shingles made with organic materials and are more lightweight.
“However,” says Kirby, “there is a bit of an installation concern when you start getting into colder weather, where fiberglass becomes stiffer and leaves a little more potential to crack. Something that’s reinforced with organic material may be a little more flexible than fiberglass.”
Fiber-cement shingles “are really going by the wayside,” says Kirby. Because of significant performance issues, they are not used in most climates.
Clay and concrete tile shingles are made of extruded clay or concrete that is then molded. These types of shingles are ideal for Southwestern-style buildings. Although clay and concrete tile shingles are very durable, they can break or chip under impact, and should not be used in areas that require high-impact resistant roofing. Also keep in mind,
Kirby notes, that concrete tile and other materials with high potential for moisture absorption are more prone to crack during freeze/thaw cycles.
Wood shakes and shingles are either sawn (shingles) or split (shakes) from wood blocks. In the past, wood shingles were treated with preservatives to prevent the growth of mold, algae and fungus. The Clean Water Act prevents the use of these preservatives, so wood has a significant downside: It requires maintenance. New pressure-treated wood options may reduce maintenance and provide a good alternative to traditional wood shingles, but their track record is short.
Slate shingles are made from rock and are more expensive upfront than other roofing materials, but are actually very cost-effective because they typically last for 100 years or more. Slate is considered a premium material, because of aesthetics and the specialized training needed for proper installation. Slate can be increasingly more expensive the further you get away from where the rock was quarried. Because of hefty shipping costs, it’s wise to buy locally or consider another alternative.
Environmental FactorsEnvironmental conditions can drive material selection. For example, pay attention to any trees that overhang the roof. “If there are a lot of overhanging trees that will deposit leaves and pine needles, they’ll eventually rot the roof if it’s not carefully maintained,” says Rheaume. “The debris will build in areas such as valleys and around skylights. For those types of roofs, we’d suggest something that will shed debris easily. Laminated shingles catch debris, and so we’d lean more toward a high-end, three-tab composition shingle, slate or other types of shingles that wouldn’t hold debris as easily.”
Double Up UnderlaymentUnderlayment is another important consideration. ”You want to make sure that you use a high-quality underlayment, maybe even a double layer, to make sure that anything that gets past the tiles is not going to enter the building,” says Kirby. “Make sure the expected service life of your underlayment matches the effective service life of the material on
top.”
Roof Shingle Comparison | Shingle Type | Materials
Cost (per square foot) | Expected Product Life (years) | Fire Resistance | Approx. weight (pounds per square foot) |
| Asphalt | $ 0.62–0.81 | 15–30 | UL Class A | 250 |
| Fiber-cement | $ 2.00 | 40–50+ | UL Class A | 225 |
| Clay or Concrete Tile | $ 8.30 | 30–50 | UL Class A | 750 |
| Wood Shakes or Shingles | $ 2.50 | 30–50 | UL Class B-C* | 250–400 |
* Pressure-treated woods are more fire-resistant
Source: National Roofing Contractors Association