Deciding upon the best roofing material for your new home or for replacement of an existing roof involves consideration of several interrelated factors. Cost may be a primary determinant, but this includes projected longevity of the materials and the length of the warranty. Not only is the roofing material itself a cost consideration, but also if the roofing material is heavy then special framing for its support will add to the cost. If the materials, such as slate, require special handling and skilled installation, then costs will also increase. Consider initial low cost versus how long the material will last and how soon it will have to be replaced versus an initial higher cost coupled with probable greater longevity, which may result in long-term lower cost. Do your roofing materials comply with your locality’s fire codes? Will the roof protect your home from other hazards, some of which may be unique to your locality? What special maintenance, if any, will your roof require? Does the material come in the color that you want? Is the roofing material appropriate for the architectural style of your home?
Here is some basic information about residential roofing materials.
1. Asphalt. In the United States, the most common residential roofing material is asphalt shingle, which covers over 70 percent of single-family homes. Fiberglass asphalt shingles are constructed of a fiberglass mesh mat covered in asphalt and granules that impart color and reflect sunlight; they are lightweight and resist tearing. Asphalt is cost-effective, easy to install, can be installed on many types of houses, may protect against fires, should last 20-25 years and is available in many colors. Architectural shingles can even mimic shakes and slate. Shingles are not heavy so standard roof sheathing is all that is required. Three-tab shingles are rated for 60-70 MPH wind uplift, architectural shingles for 110 MPH winds and high-wind shingles for 130 MPH. High-impact shingles are suitable for heavily wooded areas and for areas that receive large downpours of hail. Shingle repairs are easy and cost-effective. However, asphalt does not last as long as other roofing materials. It can crack if there are rapid temperature changes. In contrast to some other roofing materials, it does not act as an insulator. It is also among the least eco-friendly of materials: Some recycling centers won’t take these shingles. Mold or algae may appear in shady areas unless the shingles are treated with anti-algae/anti-stain treatments. After two layers of shingles are applied they must be removed and discarded when a new layer of roofing is needed.
2. Clay and concrete tiles come in flat, ribbed or scalloped clay. Fiber cement shingles consist of wood and clay blended into concrete to produce lightweight strength. Tiles are glazed or coated with waterproof coating. Because of their heavy weight, they usually require additional framing. Concrete tiles are less expensive than clay and are energy-efficient but are also very heavy. These tiles can last 40-50 years, are recyclable, resist insects and are non-combustible. Light-colored tiles reflect sunlight, which keeps homes cooler. Tiles look beautiful on Spanish, Mediterranean, Mission and Southwestern style homes.
3. Metal. Metal roofing can last 50-100 years. It can be expensive but is durable and has high solar reflectance, which works to keep your home cooler. It is lightweight, 100 percent recyclable (good for the environment), and resistant to extreme weather conditions—it sheds rain and snow better than other materials, which helps to prevent ice dams. Metal roofing is available in panels and shingles and can be made of zinc, stainless steel, aluminum and—if you have lots of money to spend—copper. It can mimic shingles, slate, shakes and tile. It is impact-resistant but can dent if hit with a large object. It can be noisy when hit by rain and hail unless it is installed over solid sheathing such as plywood. Use it on bungalows, cottages, cabins and contemporary-style homes.
4. Slate. Slate is a natural material that comes in shades of grey, green, black, red and purple. It can last up to 100 years, requires little maintenance, can be recycled, is fire-resistant and is very durable. However, its heaviness requires extra framing. It must be quarried and split into thin shingles and it can be cracked by nails and become detached as it expands and contracts. It can leak water into the house if the shingles crack and become loose. It is very expensive because it must be installed by specialists, because it is heavy to transport, and because there is wastage due to some cracking in installation and in transport. It looks great on colonial, European and French chateau styles.
5. Wood shingles and shake are usually made from redwood, cedar and Southern pine.
Shakes are hand-made and rougher looking than wood shingles, which are machine-made. Cedar and redwood contain oils that become naturally resistant to moisture and insects. Wooden roofs last 5-10 years longer than asphalt and provide twice as much insulation. Wood can be recycled. But untreated shingles need constant cleaning or they will develop algae and moss; they must be cleared of debris so that they can breathe. As the wood releases tannins, shingles and shakes may become stained. Repairs are expensive. Wood weathers to grey. Some localities do not allow their use due to fire danger, but even if your locality allows wood then buy Class A fire-rated products, including those treated with fire-resistant coating. Due to moisture, wood shingles can split, rot and develop mold, so don’t use wood if your roof does not receive much sun. Wood shingles and shakes are not as expensive as some other styles and should last 25-30 years. Wooden roofs look great on bungalows and on Craftsman, Tudor, and Cape Cod styles.
6. Synthetic roofing products. These are made of recycled rubber, plastic and polymer. In appearance, they can look almost identical to slate and can mimic wood and other natural materials. Some are fire-resistant. They are durable, easy to maintain and may be less expensive than natural products. Although they may last up to 50 years, check the quality of the materials and make certain that they do not absorb water. These products are easy to cut and to install, they weigh less and generate less waste than slate, and the color permeates the entire product. Unlike slate, these products are non-breakable and they can be installed with pneumatic nailers and cut with standard utility knives. These materials are suitable for different styles of houses.
7. Tesla solar tiles. These are constructed of glass over a photovoltaic (PV) substrate, which is wired to the Tesla Powerwall, which integrates the roof with the home’s electrical system. Depending upon the local climate and whether the home is a ranch or multi-story, 35 percent to 70 percent of the roof is covered with these tiles; the remainder of the roof is covered with glass non-solar tiles without the PV substrate. This system can generate 100 percent of the home’s electric needs and owners may receive tax credits. Tiles are guaranteed to generate power for 30 years and have a lifetime warranty against breakage and defects. But the tiles are expensive and not many roofers know how to install and to maintain them. Therefore, you may have to wait a long time for service and/or tiles could be improperly installed by an inexperienced contractor.
By Vivian J. Oleen