It’s one of those remodeling efforts that probably won’t net much return. A buyer just expects that the roof won’t leak. So be prepared to shell out no less than $2,000, even if you have a small house. And if you have a large home and exacting roofing standards, the bill can be many multiples of that.
Actually a leak is not necessarily evidence that you need a new roof. They can be caused by a variety of things, including ice dams in an incorrectly insulated attic. Roofs also leak around chimneys and vent pipes long before the shingles start to fail. But if you have bare patches on the shingles, granules in gutters, and curling, lifting or missing shingles, it’s definitely time to find a good roofer who can spell out the options for you and help you decide.
Roofing estimates can vary greatly because the proposed job can vary. It is accepted practice to cover one layer of asphalt roofing with another. The roof structure can generally support the additional weight safely. The only time this might not be true is if the old roof is in such terrible condition that big pieces of shingles are missing and/or the plywood beneath is completely rotted. In that case, even if there is only one layer of roofing, it should be removed.
If there are already two layers of roofing, then the roofer will undoubtedly suggest a tear-off. That means, the roofer will take the roof down to at least its plywood layer. He may even pull that off and replace it as well, if it appears to be rotting. Then he will nail on a fresh layer of shingles.
This extra labor and material makes the roofing job far more expensive, but it is the right thing to do if you have more than one roofing layer. The extra weight caused by a third roof can put too much strain on the roofing structure and cause collapse obviously a more serious problem than just a simple leak. The only exception to this rule is if you are switching to lightweight metal roofing, which can be applied safely over almost anything.
Barrel-shaped clay tile roofs have been around for many decades because of their inherent durability and performance characteristics.
Cool Roofing Technology
In the last few years, the color of shingles has gotten a lot of attention as both a predictor of shingle life and as a way to control temperatures in the house below. The typical dark asphalt or metal roof will get as warm as 180°, says Paul Berdahl, a materials scientist at Lawrence Berkeley National Laboratory at the University of California, where a study of cool roofs is being funded by the U.S. Department of Energy. Conventional black asphalt shingles are the hottest, absorbing 95 percent of the sun’s energy, while lighter colors like tan absorb about 75 percent.
Berdahl says that from an energy point of view, the simplest solution is to make the roof white, but from the standpoint of architects and owners, white is unacceptable. So Berdahl is studying ways to lower absorption in darker colors. He says that there are no low-absorption asphalt shingles on the market yet, but there will be by next year. In the meantime, going with the lightest-color shingle you can aesthetically accept may help lower your cooling costs.
If you have a flat asphalt roof like those found on row homes on the East Coast or on Prairie Style homes in the Midwest or California contemporary ranches in the West, he recommends a single-ply polyvinyl-chloride roofing membrane. Companies like Duro-Last (http://www.duro-last.com) manufacture them to fit precisely. Available in any color, including black, the roofs reflect 87 percent of the sun’s energy, which meets the standards of the Energy Star Products program. Berdahl says that while you can expect to pay as much as twice what an asphalt roof costs, if your home is air conditioned, you’ll make it up quickly in energy savings.
Organic-base shingles have a Class C fire rating (the least resistant), while fiberglass shingles have a Class A rating (the most resistant). Organic types are more flexible in cold weather than fiberglass ones. Some roofers don’t like to install fiberglass because they say their stiffness causes them to crack. Manufacturers reply that fiberglass installed properly is long lasting.
The two most common styles are three-tab, also called a strip shingle; and architectural, also called a laminate shingle. A three-tab shingle is a rectangular mat with two slots cut in its front edge. The slots provide stress relief as the shingle expands and contracts with the weather. An architectural shingle has a heavy base mat and another mat or sections of mat applied on top of it. Many people like the appearance of architectural shingles, and they are sturdier but more expensive.
There are considerations beyond appearance and fire resistance. In parts of the country where there’s a lot of wind, roofers may recommend a T-lock or T-shaped shingle that has a higher wind-resistance rating. But roofing manufacturer Owens Corning says the design of the shingle has much less to do with wind resistance than with the performance of the sealant and that’s affected by how warm it is when the roof is installed. For the sealant to activate properly, there needs to be enough sun to raise the roof temperature to 140° says Bert Elliott, product manager for roofing shingles for Owens Corning. If you’re in a cold climate, he advises waiting to re-roof until March or April, when the sun is higher in the sky, in order to get a good seal.
Shingles that have a high wind rating also may require six nails versus the usual four when fastening them to the roof deck. Installation of this type of shingle takes longer and costs more. Is it worth it? Elliott says let good sense prevail. If you’re on a hill in the Midwest and the next tree is in Denver, you might consider getting a higher-rated shingle. But if you’re considering buying wind-resistant shingles because you live in an area where there are occasional hurricanes, frankly, if your house is hit, you’re going to have much worse things to worry about than whether you lost a shingle or two.
Shingles are also rated for impact resistance. If you live in an area where hail is a problem, consider a shingle with a Class 4 rating. They are a little more expensive, but insurers in some states will give you a discount if you have them.
Your roofer will probably ask you whether you want a 20-, 25- or 30-year roof. This refers to the manufacturer’s warranty rather than the quality of the roofing material. Roofs last about 20 years. After that it is hard to make a warranty claim stick.
The Performance Based Studies Research Group at Arizona State University has been looking at roofing issues for the last 10 years. They have found that choosing the right roofer is much more important that choosing the right roofing materials. Researcher John Savicky advises, Call five or 10 of the roofer’s customers from at least 10 years ago, and ask them if their roofs have ever leaked and what happened when asked for a repair. Did he fix it, and did it stay fixed? From among the roofers with good track records, go with the lowest price.
Metal, Wood & Rock Roofing
Residential metal roofing is quickly becoming the roofing of choice for expensive homes. Although it is costly to install initially as much as four times the price of asphalt shingles it looks beautiful and has a 50-year average warranty. If you have ever lived with an old metal roof, you know that they once accentuated every noise, but the new ones are better insulated and are at least as quiet as asphalt-shingle roofs.
Metal roofs can be designed to look like other types of roofs. For instance, from the ground, you can’t tell a simulated cedar-shake metal roof from a real cedar one. If you prefer an elegant tile look, choose a new steel roof that uses special painting processes. Real earth-tone granules are placed on the final paint coat, which is then covered with a super-durable clear coat. If you live in a neighborhood with asphalt shingles and you don’t want your house to stand out, you can choose metal roofing that looks exactly like the asphalt roof next door.
In some circumstances, a metal roof may pay for itself over time because it saves re-roofing and insurance costs. Homeowners in snowy climates benefit from the way ice and snow slide off metal roofing. Natural fire resistance is a major selling point in California and other areas where forest fires threaten homes. Resistance to wind damage makes metal roofs a good choice in hurricane-prone areas. Metal roofing is virtually immune to the unsightly mildew growth that often forms on asphalt shingles in the warm, humid Southern states. And in parts of the country where hail is an issue, metal roofs can withstand golf-ball-sized hailstones.
Cool metal roofs, specially coated to reduce solar absorption and increase reflection, are particularly good at keeping a home comfortable. According to a study by Florida Power & Light, a properly coated metal roof can reduce cooling costs by as much as 25 percent compared with asphalt shingles.
Copper is very expensive, but its lovely green patina appeals to many people. It’s a good choice for accent roofing over a dormer or a sunroom.
Not long ago, cedar shingles came directly from the tree and, although they looked great on a house, their longevity was questionable. But today wood shingles and shakes are more reliable. Composite wood shingles will last nearly as long as asphalt, and Southern yellow pine shakes are pressure treated to resist rot and decay. While they haven’t been on the market for that long, manufacturers say they will last for 30 years.
To get maximum durability out of a cedar roof, roofing contractors recommend you clean it with a pressure washer once or twice a year to remove moisture-holding debris and apply preservatives to help it resist sun and weather. Pine and cedar shakes both are generally twice the price of premium asphalt roofing.
Clay tile is among the oldest and most durable roofing materials. It gains its weather-resistant, fireproof and insect-proof qualities from its construction of kiln-fired clay. Most people think these tiles are limited to the barrel-shaped type common in the West, but clay tiles can be flat, and they may have a glossy surface. They are also available in blue and green, as well as the traditional reddish brown.
Cementitious roof tiles are a first cousin to tile, and they offer the traditional look as well as the longevity of manufactured materials. These products are made from cement or concrete. They are available in red, black, white, green and gray, and they can be molded to look like barrel-shaped tiles or slate. Cementitious roofing is very durable. Because it is a masonry material, it resists weathering, insects and fire. The nearly impenetrable surface of these tiles also resists the formation of fungus, and because they are heavy, they resist wind uplift.
For either clay or cementitious tile, expect to pay two or three times as much as you’d pay for a premium asphalt shingle roof.
Properly installed, slate has timeless durability. And it doesn’t require much maintenance, although a cracked tile or two in an old slate roof might have to be repaired or replaced.
New slate roofing comes in gray, purple, green and red. It is available in two types premium clear and ribbon slate. Ribbon slate is not as durable as the premium clear product. The ribbons of light color that run across its surface distinguish it. The ribbons are high-carbon-content areas. They are impurities in the slate and are weaker than the dark areas.