Make a your roof more energy-efficient using in 3 types of way
1) Cool your roof
“Cool” roofs are lighter in color than traditional black asphalt or dark wood shingles and save energy by reflecting light and heat away rather than absorbing them. This is known as “the albedo effect,” and many studies have documented significant energy savings from simply lightening the color of a roof.
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The problem with dark roofs: The temperature outside may be 95 degrees, which is plenty hot, but your dark roof is conducting a much higher temperature down toward you and your family, making the rooms below hotter and forcing the air conditioner to work harder, as Barbara Collins points out in her answer to the Ask A Pro question “NYC has a ‘cool roof’ program. Is there a white paint or coating to make my roof cooler?” In New York City, she notes, a dark-colored asphalt roof can reach 150 to 175 degrees on a hot summer day. This not only increases the energy needs of your home, it also contributes to the heat island effect in urban areas.
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The benefits of cool roofs: A cool roof, on the other hand, can be 50 to 60 degrees cooler than a conventional dark-colored roof, reducing the cooling load on your home, saving energy and reducing utility costs. By decreasing the solar gain and heat retention of your home, a white roof also increases its comfort and reduces the heat island effect to which your home’s dark roof contributes.
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How to cool your roof: The easiest route is to slap a cool roof coating onto an existing roof. Check out these recommendations from David Edwards, PhD, of EarthBound Homes, for coating options. If you’re already re-roofing, or building a new residence, consider replacing shingles or asphalt with lighter-colored versions. If you have a flat-top roof, Edwards suggests DuraLast’s sheets of fiber-reinforced white PVC membranes, in his Q&A “I’m reroofing a typical sloped roof—what materials should I be considering?” A quick search of the Cool Roof Rating Council’s Rated Products Directory will provide you with performance data about various roofing products. Products are rated for their reflectiveness: the higher the number, the more reflective the product is, and the cooler your roof will be.
2) Insulate from below
Insulation is one of the first things people think of when they set about making their homes more energy-efficient.
According to the Rocky Mountain Institute (RMI), the attic is usually the top priority, because installing insulation there is easy and provides immediate benefits. When insulating the attic, it’s important not to forget about the roof. Unfortunately, deciding on the best insulation isn’t always so straightforward, but our experts have advice on everything from the materials you should consider to how they should be installed.
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The problem: Roofs are your heating and cooling system’s biggest nightmare. A poorly insulated roof will require more air conditioning in the summer and more heating in the winter, and will make your attic uncomfortable for use as a bedroom or study. Even if you do have insulation, it may not be enough. Check out Steve Saunders’s comprehensive answer to the question “Is three inches of batt insulation enough for my attic?” for more information.
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the benefits of insulation: A well-insulated roof, on the other hand, can almost negate the need for either mechanical system and will drastically reduce your heating and cooling needs (along with your electricity bill and your home’s emissions). Mick Dalrymple, in his answer to the question “What type of roof should I choose in a hot climate?”, describes how his roof’s insulation and weatherization coatings make air conditioning unecessary until outdoor temperatures reach over 100 degrees in Scottsdale, Arizona.
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How to properly insulate your roof: The material you choose will depend heavily on the type of house you have and the climate you live in. Our experts have advice on everything from the more high-tech solutions such as home foam insulation (even a cogent answer to the open cell vs. closed cell foam debate) and cellulose insulation to simpler options such as fiberglass or cotton batting. Those with open beams (especially cathedral ceilings) in cooler climates should also consider a radiant barrier—simple reflective film that wraps around beams and reflects heat rather than absorbing it. No matter what material you choose, leaving an air space between the insulation and the roofing material is generally a good idea. Although in very dry climates, and with some metal roofing, it may not be necessary, an air space will typically reduce the possibility of moisture getting trapped in either the structure or the insulation and causing mildew or mold to grow. Read Mike Binder’s answer to the question “Should I leave an air space between my attic insulation and the wood roofing?” for more details.
3) Re-roof sustainably
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Whether you’re putting a roof on a new home, or re-roofing an existing residence, it’s a golden opportunity to do things as sustainably as possible.
But with new, supposedly green roofing materials coming to market every month, it’s hard to separate the great from the greenwashed. In her answer to the question “What are the sustainable options for re-roofing our 30-year-old home?”, Cynthia Phakos advises that anyone looking to re-roof their house start not by reading about the coolest new roofing materials, but by understanding their home’s specific conditions, particularly climate. -
The problem: You want to choose a roof that lasts a long time, improves your home’s efficiency and comfort, and reduces the heat island effect. That ideal roofing material will shift depending on where you live and the sort of house you have, but our experts agree that wood shingles are probably not going to cut it no matter where you live, primarily because they degrade rather quickly and it’s not sustainable to replace your roof every 15 years.
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The benefits of sustainable roofing materials: Simply choosing the right material could result in as much as a 30 percent decrease in your home’s energy needs. Whether that ends up being a metal roof (which is generally more expensive, but does deliver meaningful energy savings), tile roof, asphalt shingles, concrete or even wood, all of our experts recommend reflective coatings to make your roof cool. Elastomeric rooftop coatings not only reflect heat, and thereby save energy, but they can also extend the lifetime of your roof.
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How to sustainably re-roof your home: Any decent roofer should be able to advise you on the best roofing material for your house type and climate, but it’s a good idea to have a grasp of the basics before talking to a professional. “If you live near the coast, you’ll want to select roofing that will withstand the salt spray and have no wind uplift,” Phakos writes. Once you’ve got a solid understanding of the conditions facing your roof, you’ll need to consider both roofing materials and sheathing. If you’re taking the roof down to the rafters, particularly if you live in a cooler climate, consider installing a sheathing with a radiant barrier—a laminated sheet of aluminum that will reflect heat into your home instead of absorbing it.
The Flat Roofs
The traditional hot-tar-and-gravel roof is built from three or more plies of waterproof material alternated with hot tar and ballasted by a layer of smooth river stone. Once made of tar paper, these types of roofs gradually are using more-advanced materials such as fiberglass membranes.
A single-ply rolled roof similar to ice-and-water shield, but impregnated with a mineral-based wear surface. Torch-down systems involve heating the adhesive as the material is unrolled. Newer peel-and-stick systems are safer and easier.
EPDM (short for ethylene propylene diene monomer) is a true rubber. The durable material resembles an inner tube, but it’s engineered to resist damage from sunlight. EPDM can be mechanically anchored with fasteners, ballasted with stone, or glued.
1. Slate Roof
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Lifespan: 100+ years.
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Why: Slate is so durable it makes all other roofing materials look like rice paper. Slate roofs from Shakespeare’s time are still holding tight. Slate is real stone, laid down thick on the roof. But adequate truss strength is required to hold up this heavy load.
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Make It Last Longer: Immediately replace broken slate tiles. Make sure that all flashings are correctly installed and in good working order. When your copper flashing has turned black, it is time to replace it.
2. Clay (Spanish) Tile Roof
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Lifespan: 100 years.
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Why: Spanish tile roofs from the old California missions are still in service. Travel across Spain and South America and you will find even older Spanish tile roofs in reasonably good shape.
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Make It Last Longer: Tile roofing’s Achilles heel is not decay (like wood shake or shingles) or the slow sloughing off of grains (like composite). Rather, cracking of these terra cotta tiles is what usually dooms them. Avoid walking on your tile roof as much as possible. When efflorescence develops, buff off with a clean, dry towel. Coat with a clear alkyd primer. Replace cracked and broken tiles.
3. Wood Shake Shingle Roof
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Lifespan: 35-40 years.
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Why: Wood shakes are much thicker than wood shingles (see above). Shakes are split or sawn from the log. In either case, these thicker shakes can stand up to weather and UV rays better than thin wood shingles.
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Make It Last Longer: Thick wood shakes can last well over a quarter century, but you do need to baby them along with proper maintenance. There is no “set it and forget it” option for any kind of wood shingle. Remove debris as soon as it falls on the roof. Eliminate moss. Replace split shakes right away. Replace curled, cupped, or split shakes immediately.
4. Standing Seam Metal Roof
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Lifespan: 30 to 50 years.
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Why: Pre-formed standing seam metal roofing is mainstream now. After all, what can be stronger than metal overhead? But metal roofs are not for the average roofing company; make sure you contract with a company that specializes in metal roofing.
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• Make It Last Longer: Regularly walk your standing seam metal roof to check for fastener and sealant failures. Check for distressed, bent, or migrating panels.
5. Wood Shingle Roof
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Lifespan: 25 years.
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Why: Wood is an organic material. As such it is prone to weathering and decay. Note that these are wood shingles, not shakes (see below). Since shingles are sawn from the log, they are thin and flat.
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Make It Last Longer: Replace split and cracked shingles immediately. Control moss growth.
6. Composite Shingle Roof
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Lifespan: 15 to 50 years.
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Why: Are you surprised that the most popular form of roofing material ranks so low on the list of expected lifespans? Try not to be shocked. While they might poop out in as little as 15 years, composite shingles are cheap to purchase and install. Longevity predictions for composite/asphalt shingles vary wildly because the quality of this popular material varies wildly. Premium composite shingles from manufacturers like Owens Corning, GAF, or Certainteed come with accordingly high-end warranties pushing a half century. But that does not mean that your roof will last 50 years.
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Make It Last Longer: Watch out for cheap composite shingles that start to shed grains even in the first year. Never power wash your composite shingle roof. Eliminate moss as soon as it begins to grow./p>
7. Asphalt Roll Roof
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Lifespan: 5 to 10 years.
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Why: Asphalt roll roofing is a piker: it is better suited as a weekend Ar roofing project for your wood shed. Do not consider using it for your home.
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Make It Last Longer: There is little you can do to prolong asphalt roll’s lifespan. Make sure that it is clear of debris.
If you are planning to add a new roof to your home or shed, be sure to consider all the available options. Pitched roofs come in a variety of styles, such as gable, cross gable and hipped, all of which are sloped to different degrees. Flat roofs have no slope, and are available in built-up, single-ply and sprayed polyurethane foam designs. Consult with a roofing contractor to determine which roofing option is best for your individual needs.
Maintenance
Both flat and pitched roofs require regular maintenance. However, although pitched roofs may be more difficult to clean and inspect, due to the sloped structure, flat roofs often require more maintenance throughout the life of the roof. Flat roof drainage is not quite as effective as a pitched roof’s, and without regular inspection, drains can become clogged, leading to damage and leaks. The roof requires a waterproof seal, which must be maintained regularly to prevent leaks and costly repairs. Many flat roof leaks are due to a lack of regular inspection and maintenance, so be sure that you have the time to check your roof regularly if you choose a flat roof for your property.
According to Improve Net’s online roofing calculator, a flat roof is significantly cheaper than a pitched roof. A 900-square-foot flat roof in the San Francisco area, made of concrete tiles, costs approximately $6,108 to $7,635, whereas a moderately pitched roof with the same specifications ranges from $7,878 to $9,848. Of course, if you live in an area that receives a large amount of rainfall each year, any money you might save in flat roof installation costs might be compensated for in future repairs. Flat roofs’ repair costs are more expensive than pitched roofs’ are, and because they are less prone to moisture damage, a pitched roof may be more affordable in the long-term.
Before you learn anything else about roof color, take away this fact: roof color affects your home’s internal temperature. In general, lighter-colored roofs reflect away heat rays from the sun, but dark-colored roofs absorb much of that heat and transfer it into the rooms below.
Or course, color isn’t the only aspect of your roof that affects home temperature. The roofing material also affects how reflective your roof is. For example, asphalt shinglesare less reflective than metal or rubber roofing materials. This quality means even tan asphalt shingles may welcome more heat into your home than a dark brown metal roof.
But back to roof color. How does your roof color affect the temperature of your home? If you have a light roof, your home absorbs less heat through the roof during summertime. As a result, your air conditioner operates more efficiently, uses less energy, and leads to lower utility bills.
In contrast, a dark roof likely raises the temperature inside your home’s highest rooms. Your cooling system works harder to compensate for the extra heat, and your bills slowly rise.
But during the winter, the opposite conditions hold true. A dark roof brings in more desired heat from the sun than a light roof. This feature makes dark roofs advantageous in colder climates with long winters and short summers. Now, let’s consider how one other factor affects the equation: snow.
How Roof Color Affects Snow Melt Because dark roofs absorb more heat, they have a reputation for helping snow melt. This notion is another reason dark roofs remain popular in northern areas like the Twin Cities. But do dark roofs really help snow melt away? Probably not as much as you think.
First, consider that northern cities have fewer sunny daylight hours during the cold winter months. And less sunlight exposure means fewer beams beating down on a roof and less time for the roof to absorb that heat.
Next, remember that even black roofs may not actually appear dark during the winter-because they’re covered in snow. The white powder actually reflects away much of the sunlight, so the dark roof underneath cannot absorb heat and melt the snow.
Dark roofs may have a small snow melt effect but not a sizeable one. Similarly, if your roof experiences winter problems like ice dams, your roof color probably isn’t the primary culprit. More likely, insufficient attic insulation and poor roof ventilation create the problem. Ask a roofing specialist to evaluate your roof and recommend solutions.