How To Reflect Heat From Roof?

Download Article Download Article There are a variety of ways to protect your roof from sunlight and heat. If you have a flat roof, the easiest way to avoid sun damage is to cover your home in a reflective coating. You can also pour gravel or plant a garden to cover your roof and protect it from direct sunlight.

  1. 1 Cover a flat roof with reflective paint to keep the heat off. Cool roof coatings are white or silver paints that are made with reflective pigments. Cool roof coatings are the most commonly-used method to cool roofs because they’re inexpensive, easy to use, and don’t require help from a contractor.
    • In roofing, the term “cool roof” is used to denote a roof that is specifically designed to reflect heat.
    • If your roof is made of shingles or asphalt sheeting, your roof is already designed to reflect heat and should not be painted. If you want to cover a metal roof, get a coating designed specifically for metal.
    • Cool roof coatings are almost always waterproof as well.

    Warning: If your roof sits on an angle, you cannot apply this coating. The coating essentially works like a mirror, and you could blind your neighbors and nearby motorists if your roof is visible from the ground. Painting a pitched roof is often illegal without a license as well.

  2. 2 Pour gravel on your flat roof if you want an added layer of protection. If you have a flat roof, you can add a layer of reflective gravel to protect the roof from sunlight while helping with drainage. Purchase reflective gravel from a roofing company or at a home repair store and take it up to your roof.
    • You cannot add gravel to a roof that doesn’t have a rim around the exterior of the building. If there’s no barrier, your gravel will simply slide off of the roof over time.

    Warning: Do not add massive heaps of gravel. They won’t be as effective as a clean, even layer. Large piles may also become hazardous over time as the weight weighs down your roof. Keep your layer of gravel thinner than 2 inches (5.1 cm) to avoid any structural problems. Advertisement

  3. 3 Plant a garden on your roof if it’s flat and easily accessible. A rooftop garden is a great way to take advantage of the large amount of sunlight while blocking the surface of the roof from the sun. While you won’t be able to completely cover your roof, you will be able to protect a large majority of the surface.
    • Your roof must be structurally sound to handle the weight of a large garden. Contact an architectural or engineering firm to inspect your roof before installing a garden.
    • Most roofs don’t have access to a running supply of water, so you may need to store water on the roof or run a hose up to the roof.
  4. 4 Get a contractor to cover your roof with polyurethane foam if it’s sloped. To waterproof your roof while protecting it from the sun, hire a contractor to install a polyurethane foam on top of your roofing material. The contractors will clean your roof and use an aerosol spray to seal your roof in polyurethane foam.
    • It is illegal to install a polyurethane foam roofing membrane if you aren’t a licensed contractor. You must hire someone to install it for you.
    • Polyurethane foam coatings cost $4-7 per square foot ($13-22 per square meter).
  5. 5 Hire a contractor to install a reflective membrane if you have a sloped roof. Roof membranes are prefabricated sheets that are attached to a roof using fasteners. They reflect sunlight and keep weather from wearing down your roof over time. You cannot install a membrane yourself, so contact a contractor in your area to get quotes for a roofing membrane.
    • This is the best option for sloped roofs that can’t be painted with a reflective coating. However, if you already have an asphalt or shingle roof, you may not see a ton of improvement.
    • Roofing membranes typically cost $4-5 per square foot ($13-16 per square meter).
  6. 6 Get solar panels installed to cool your roof and cut your utility costs. Solar panels are designed to attract sunlight in the area around them. In addition, they physically cover a large portion of your roof, partially shielding it from exposure to the sun. This can lower the temperature of your roof considerably while saving you money at the same time. Buy solar panels if you can afford the upfront cost and want a long-term, sustainable solution to keep your roof cool. Tip: While it can cost $10,000-30,000 to initially install the solar panels, the prices come down every year as the technology improves. They also pay for themselves over a longer period of time as your electric and gas bills go down.
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  1. 1 Install radiant roof barriers to insulate your attic. While it won’t limit your roof’s contact with the sun, radiant roof barriers can keep heat off of your roof by limiting the space where the heat can go. Purchase a roll of radiant roof barrier from a supplier and spread it out along your wall.
    • Radiant roof barriers are typically installed in an unfinished attic where there isn’t much interior insulation.
    • Use a utility knife to cut slits into the sheeting to wrap it around any pipes or columns.
    • The barrier doesn’t need to be taut or airtight to work effectively. So long as the majority of your attic’s walls are covered, most of the heat from the sun will struggle to enter your home.

    Tip: This can be kind of tricky to do without the help of friend holding the opposite end of a sheet up. Ask a friend or family member to stabilize the sheets for you as you staple.

  2. 2 Put a fan or AC unit in your attic to improve ventilation. Keeping your attic properly ventilated is an excellent way to naturally lower the temperature of your roof. Install a ceiling fan or set up a large industrial fan in your attic. If you want to cool the attic independently of the rest of your house, install a window unit in a window in your attic.
    • Keep in mind that any of these options will cause your electricity bill to increase. However, your air conditioning costs will certainly go down in the summer.
  3. 3 Install a solar-powered fan to force air through your roof’s vents. There are air gaps built near the floor where your pitched roof meets the floor. To increase the natural ventilation in your attic, get a solar-powered fan designed to push more air through the vent.
    • The benefit of a solar-powered fan is that it will only kick on when the sun is out. This will naturally regulate the temperature in your attic.
    • You can hire a contractor to install one of these fans for you.
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If your roof isn’t flat, don’t risk getting up on your roof. It’s better to hire a contractor than risk your life to keep your roof cool.


  • Reflective coating
  • Roller
  • Roller extension
  • Screwdriver
  • Reflective gravel
  • Gardening tools
  • Planter boxes
  • Pots
  • Solar-powered fan
  • Fan
  • Air conditioning unit
  • Shovel
  • Radiant barrier sheeting
  • Utility knife
  • Gloves
  • Staple gun

Thanks to all authors for creating a page that has been read 35,692 times.

What is the best roofing material to reflect heat?

If you live in an area with soaring summer temperatures, it is important to consider the best roofing materials for heat and hot climates. The shingles on your roof play a pivotal role in the longevity of your roof, and the energy efficiency and comfort of your home.

  • While popular, asphalt and wood roof shingles are not best for areas that experience triple-digit temperatures.
  • The best roof types for homeowners in hot climates are metal, slate, clay, or rubber shingles.
  • Metal roofs are perfect for hot climates because they excel under extreme temperatures.
  • Metal is reflective and considered a “cool roofing” material.

Highly reflective paints and coatings can even further improve your roof’s energy efficiency. Metal roofs have continued to increase in popularity, Twenty years ago, the metal roofing market share was just 3.7 percent6. But a recent independent study conducted by Dodge Data and Analytics found the 2016 market share for residential metal re-roofing is now 14 percent.

  1. This is partly due to the material’s longevity— metal roofs can last two to three times longer than a typical asphalt shingle roof,
  2. Metal is also fire-resistant and viewed as a safer material for a hot environment compared to other roofing types.
  3. After several years, exposure to the elements will cause your protective coating to wear down, but a simple re-coating is all the maintenance a metal roof needs.

Metal roofing typically costs anywhere from $7 to $10 per square foot. While a metal roof is a significantly larger investment than an asphalt roof, the energy savings in your home combined with the potential for a higher resale value can make it a worthy investment for a new construction or roof replacement.

How do you deflect the sun from the roof?

T here’s no shortage of measures that homeowners and businesses can take to lessen their environmental footprint – from better insulation and double glazing, to easing up on air-con usage and swapping in LED lights. One part of the house that seems to be attracting more than its fair share of attention is the roof.

Replacing a standard roof with a lovingly cultivated green roof of plants or adorning it with increasingly trendy solar panels can do wonders for reducing a building’s carbon footprint. Rooftop solar panels are an obvious option for many, and increasingly affordable. The average price of a residential solar photovoltaic (PV) system has been steadily dropping, from $2.40 per watt in 2012 to $1.58 per watt in March this year, according to Solar Choice’s PV price index,

On the commercial front, too, prices are at an all-time low of just $1.23 per watt, Add to this the advent of affordable battery storage systems, and Tesla’s plans to roll out roof tiles that dispense with the need for separate solar panels over the coming months, and rooftop solar has never been more attractive. Tesla’s design for low-profile solar roof tiles Photograph: Tesla But a building’s rooftop can be used for more than just harvesting the sun’s rays. Indeed, cool roofs aim to do exactly the opposite, reflecting as much of the sun’s energy as possible.

A flat roof in the midday sun receives about 1,000 watts of sunlight per square metre. A dark roof will absorb most of this energy, heating the roof and underlying building, as well as the surrounding air. Air conditioners that suck in this hot air can further exacerbate a building’s cooling requirements.

“If you have a cool roof, that problem can be eliminated,” says Geoff Smith from the University of Technology Sydney, a specialist in green roofing technologies. The easiest way to reflect the sun’s rays is to paint a roof white – something the Greeks have been doing for centuries.

A white roof reflects around 85% of the sunlight that hits it – at least when it’s clean – and heats to just a few degrees warmer than the outside air temperature. A black roof, by contrast, can heat to more than 80C, according to sustainable construction expert Chris Jensen from the University of Melbourne.

“On a black tile roof, you could fry an egg, and on a cool roof you could walk on it in your bare feet,” says Jensen, “that’s the magnitude of the difference.” Recently, Smith’s group and others have produced roof coatings that keep roof temperatures even lower than the ambient temperature.

They achieve this by reflecting sunlight using thin plastic sheets – akin to a plastic food wrap – often combined with layers of silver and other reflective nanoparticles. But there’s a catch. “These experiments might look marvellous in the scientific literature,” says Smith, but in most cases, they “just won’t work in practice.” That’s because most of these super-reflective coverings look essentially like a mirror.

For a sloped residential house, the result would be an eyesore, if not a danger to nearby road users. Unlike green roofs, which can require considerable infrastructure to support and maintain, cool roofs can be achieved with a painted-on coating to an already existing roof.

  • While white reflects the most visible light, coloured roofs can also be made cooler by coating with materials designed to reflect light in the infrared spectrum, which also contributes to how hot a roof gets.
  • When combined with an elastomeric weatherproof coating, upgrading to a cool roof can add years to the life of an ageing roof, says Jensen.

The benefits of a cool roof extend beyond the building it sits upon. The heated air that sits above dark roofs is a large contributor to the urban heat island effect, which can put urban temperatures three to four degrees warmer than surrounding areas.

Modelling of urban heating in Chicago estimated that the air temperature above cool roofs would be reduced by 7-8C compared with conventional roofs. Cool roofs even outperformed green roofs – by about a degree. The energy savings are also large. Increasing a roof’s reflectivity from 10-20% to around 60% can cut a building’s cooling costs by more than 20%.

But not all buildings benefit – a high-rise apartment or office block won’t reap anywhere near the same benefits as a sprawling low-rise warehouse, shopping centre or airport, or even a single-story dwelling. As an added bonus, work by Jensen and his colleagues has shown that solar panels installed on a cool roof produce almost 7% more electricity on a typical day than those installed on a conventional roof.

  • At a global level, the impact is nothing to be scoffed at.
  • In 2009, researchers at the Lawrence Berkley National Laboratory in the US estimated that some 24 gigatonnes of carbon dioxide emissions per year could be offset if the world’s cities adopted cool roofs – not bad considering that urban areas constitute just 1% of Earth’s land area.

The offset for a single house with a 100 sqm roof area is around 6 tonnes of carbon dioxide – a decent chunk of the 26 tonnes per capita of greenhouse gases that Australians are currently emitting. One criticism of cool roofs is that the benefits of cooling in summer can be outweighed by an increased demand for heating in winter.

How can I make my roof more reflective?

6. Select the Perfect Shingle – For the steep-sloped roofs found on most U.S. homes, standard fiberglass asphalt shingles can be replaced with cool asphalt shingles that help to reflect sunlight better. Bouillante/Getty Images For the steep-sloped roofs found on most U.S. homes, standard asphalt shingles can be replaced with cool asphalt shingles containing specially coated reflective granules to help them better reflect sunlight.

  1. Shingles made from wood, polymer and metal can also be coated to improve their solar reflectance.
  2. Shingles are generally not as reflective as any of the cool roof options available for low-sloping roofs, but their familiar appearance and traditional style make them a popular choice for residential construction.

A cool shingle with white granules costs about the same as one with the old, standard dark asphalt granules, while a shingle with its specially coated granules colored to match the desired color of the roof can cost a little more.

What blocks heat from the sun?

2. Blackout Window Blinds – Installing blackout blinds over your windows is a good way to prevent sun heat from getting in. Blackout blinds are opaque, so they don’t let any light pass through. They are also available in a wide variety of colors and designs, so you can choose the right ones for your home. How To Reflect Heat From Roof

What color roof reflects the most heat?

Energy Efficiency – As mentioned earlier, light-colored roofs are known for energy-saving capabilities, Your roof significantly impacts the temperature inside the building, and a dark roof is more likely to conduct a warmer temperature on the structure below, increasing cooling efforts such as air conditioning.

Additionally, dark shingles can absorb enough heat that the surface can become hotter than the temperature outside. A darker roof might seem beneficial for structures in colder climates as dark shingles can help melt the snow and ice more efficiently. However, the reduced energy load in the winter doesn’t seem to be sizable,

White or light-colored roofs reflect heat rays from the sun, keeping the attic and rooms below it cool during warm weather. As a result, the building’s cooling load decreases, helping home and business owners stay comfortable and save money on their energy bills. How To Reflect Heat From Roof

Does heat reflective paint work?

How does this heat reflective paint work? – Using light colors to reflect heat and keep thermal mass cool in hot climates is nothing new, Villas in Spain and Greece are perfect examples of that, where white paint has been the main strategy for natural cooling of homes and buildings for centuries.

  1. The LEED for homes rating system even rewards points for buildings who’s roof surface meets a certain reflective criteria (29 SRI – solar reflective index) What is new about this is that it is a doubled-layer paint, so it has heat reflective qualities but it is not limited to white.
  2. This paint consists of a top layer that offers options in color, and an underlayer that reflects near-to-short infrared wave lengths, reducing the surface temperature of the wall.

The intended use is not just limited to homes and commercial buildings such as Data centers that have enormous cooling loads, it can also be used for electric vehicles, and the implications are significant. By reducing the need for cabin cooling, that can lead to extended range of the best EVs, making them an even greater option over gas-powered cars. Does Heat Reflective Paint for Walls, Roofs & Concrete Work? According to the study leader Dr. Yijun Chen, of Columbia University in New York – “The paintable bilayer designs, which substantially outperform commercial monolayer paints, demonstrate a practical and efficient solution to cooling colored objects in a green and energy-saving manner.” While highly-reflective surfaces can have a notable effect on reducing energy consumption, the downside is that they can cause eye damage.

  1. It was this reality that led the team at Columbia University towards developing a double-layered paint with a thickness of half a millimetre.
  2. In addition to reducing the glare, this can offer the same energy-savings from heat reflection without being limited to white.
  3. This ultra-thin layer contains interconnected micro-pores and nano-pores which reflect infrared light, a type of electromagnetic wave that transfers heat.

The top layer of the paint contains colorants and TiO² (titanium dioxide), which is already being used to add opacity to paint. When compared to traditional single-layer paints, the results showed higher reflectance values for each color. “The top layer absorbs appropriate visible wavelengths to show specific colors, while the underlayer maximises the reflection of near-to-short wavelength infrared light to reduce solar heating,” said Dr Chen.

“Consequently, the bilayer attains higher reflectance compared with commercial paint monolayers of the same color and stays cooler by as much as three to 15.6 degrees Celsius (28°F) under strong sunlight.” To date, findings indicate that the paint works almost as well at lower temperatures as it does at warm temperatures.

There is no telling for sure when this will be available commercially, but when additional information becomes available we will update this page and our members – so be sure to sign up today !

How do I cool my roof space?

How do you put a good roof ventilation system together? – A good ventilation system isn’t too complicated. It consists of vents and a fan. The vents let fresh air in and stale air out. The fan speeds up the process. Universal Fans stocks a range of products for this purpose, including super efficient solar powered fans and mains-powered roof ventilators.

  • The trick to making sure that your ventilation system works well is putting the fan and vents in the right spots.
  • Install the fan high in the roof because warm air rises.
  • From a high point, the fan will be able to move the warm air.
  • The out going vents should also be placed high in the roof.
  • The fan draws in fresh air from the lower vents, pushing the warmest air (highest in the roof) out through the high vents.

Of course it’s unusual for a roof to have no existing ventilation. It’s important to make a thorough assessment of the existing spaces where air may enter and exit the roof cavity. This includes gaps between tiles and weatherboards. Place incoming vents low in the roof, ideally in a cool place. How To Reflect Heat From Roof Summary – Mechanical ventilator at highest point of roof to extract warm air. Passive vents under eaves to allow for fresh (ambient temperature) air to enter the roof space. The combination of both results in a noticeably lower temperature during summer. How To Reflect Heat From Roof Length of Roof x Width of Roof x 1/2 Height of the Roof = m3 roof size m3 roof size x Air exchange Target (we recommend 10) = total m3/hr volume required

What material is best for blocking heat?

1. Fiberglass Insulation – Fiberglass is the most common insulation used in modern times. Because of how it is made, by effectively weaving fine strands of glass into an insulation material, fiberglass is able to minimize heat transfer. The main downside of fiberglass is the danger of handling it.

Since fiberglass is made out of finely woven silicon, glass powder and tiny shards of glass are formed. These can cause damage to the eyes, lungs, and even skin if the proper safety equipment isn’t worn. Nevertheless, when the proper safety equipment is used, fiberglass installation can be performed without incident.

Fiberglass is an excellent non-flammable insulation material, with R-values ranging from R-2.9 to R-3.8 per inch. If you are seeking a cheap insulation this is definitely the way to go, though installing it requires safety precautions. Be sure to use eye protection, masks, and gloves when handling this product.

What color roof reflects the most heat?

Energy Efficiency – As mentioned earlier, light-colored roofs are known for energy-saving capabilities, Your roof significantly impacts the temperature inside the building, and a dark roof is more likely to conduct a warmer temperature on the structure below, increasing cooling efforts such as air conditioning.

Additionally, dark shingles can absorb enough heat that the surface can become hotter than the temperature outside. A darker roof might seem beneficial for structures in colder climates as dark shingles can help melt the snow and ice more efficiently. However, the reduced energy load in the winter doesn’t seem to be sizable,

White or light-colored roofs reflect heat rays from the sun, keeping the attic and rooms below it cool during warm weather. As a result, the building’s cooling load decreases, helping home and business owners stay comfortable and save money on their energy bills.