A key way to keep your roof and your home cooler is using heat reflective roof paint. There’s been a lot of scientific research and case studies to back up the impact of utilising heat reflective coating on your roof in recent years. Applying this coating to your roof can make your home more energy-efficient and cut down how much power you are utilising on airconditioning. If you’re looking for answers to the most frequently asked questions about the purpose and effectiveness of coating your roof with heat reflective paint, then carry on reading.
Your Roof and Heat Reflection
Several factors have contributed to the growing awareness of the impact of climate change and global warming as well as the importance of assessing energy consumption and energy efficiency. More people are thinking about going green, and with rising energy costs, it’s never been more crucial to save energy. Much of the electricity bill of the average household goes towards heating.
People need to insulate their homes and keep heat in, especially in places when the winter temperatures reach freezing conditions. During the hot summer months, cooling the home in the most energy-efficient method is also vital.
A major contributor to the heating capabilities of any building is the roof. Both the material and the colour of the roof can drive up your heating and cooling spending or cut them down significantly. One of the key ways to cool the roof down is using heat reflective paint. We are going to look at some of the figures that back this up.
How to Cool Your Roof
We know that a cool roof is good for making the inside of a building more temperate. The most effective method of making your roof energy-efficient and colder is to replace it with a new roof with a better design and better reflective properties. This is particularly helpful if your roof is older and has outdated materials. Replacing the entire roof is a big job with associated costs, so this might not be the easier option to execute.
There are two main ways to make your existing roof refreshing. The first method is using heat-reflective material to retrofit your roof. The sun releases solar radiation, and the more of this that can be reflected rather than absorbed, the lower the roof temperature is going to be.
The second method is to cover the roof with a waterproofing surface. Heat reflective coating is an example of this, and we are going to look into what this is and how it works in depth in this post.
Benefits of a Cool Roof
There are numerous benefits of a cool roof, both immediately and long-term. These benefits impact the owner of the building and also contribute to the grander scale of things, both financially and environmentally.
The main benefits have been discussed already. If a room heats up less by absorbing less sunlight and reflecting more of it, the house or building is going to heat up less. This cuts down the costs of electricity for airconditioning. Not every roofed area is airconditioned, so a cool roof can also improve areas such as your patio and garage more to be comfortable. When the roof heats up less, this also preserves it further and extends its useful life.
Looking at the big picture, we see that cool roofs also contribute to sustainability, reduce the pressure on the electricity grid, and the harmful effects of power plants utilising fossil fuels. These roofs lower the local air temperature. They also reduce the demand for energy. Several power plants release harmful emissions which lead to global warming air pollution. Making your roof more energy-efficient is a way to create an improvement, even if it is on a small scale.
The material used for your roofing is also important to consider because it can impact the heating in the home.
It is common knowledge that some colours deflect more heat than others. Light colours are popular in summer for this very reason. Dark colours are more commonly worn during the winter when people want their clothing to retain more infrared heat than they are reflecting. Taking this a step further, it’s natural to assume that a light colour roof is more likely to reflect a lot of heat than a dark alternative. This concept has been applied in several places around the world, with some significant noteworthy results.
Ahmedabad City Pilot Project
In a notable and much-cited study conducted in India, the impact of painting roofs white was measured. Ahmedabad is a city in western India. It can get very warm in summer, with temperatures going as high as 50 degrees C. In the study, which took place in 2017, the roofs of 3000 houses were painted with white lime. In addition to this, a special reflective coating material was added. The impact of this study was significant. They found that the indoor temperatures of the houses in the study was low compared to the normal by an average of 2C.
Other scientific measures and tests have also shown that It found that a clean whitened roof reflecting up to 80% of sunlight on a hot afternoon, stays around 31C cooler than a dark colour alternative.
What Is Roof Coating?
Roof paints are fluid membranes that adhere to the roof to improve its functions. The three main benefits of roof coating are improved protection, cost savings, and energy savings.
There are various types of roof paints, and they may serve various purposes. In an area where heavy rainfall is a common occurrence, for example, a bituminous roof coating could be used to waterproof the roof to prevent water damage. Besides this type of roof coating, there are three other main types to consider.
Elastomeric roof paints have elastic properties. They are flexible and can stretch without causing damage to the roof. Their purpose is to allow for building movement and thermal expansion when the weather flexibility means the roof’s surface can stretch without being damaged. This coating is the most common type of non-bituminous roof paint.
Polymer-modified roofs fall under the bituminous category but have added polymer for improved performance. This type of coating makes the roof surface more flexible and longer-lasting. The main drawback is that it is more expensive than roof coating that has not been modified.
The third type is the heat reflective roof coating. Find out more about this in the next section.
Does Heat Reflective Roof Coating Reduce Heat?
Heat reflective coating is an effective way to reduce heat in the roof and the entire building. These coatings reflect the sun’s rays. They tend to be in a light reflective colour, with the most popular light colour choice being white. Heat reflective coating is categorised in the cool roofs section. Some examples of heat reflective paints and coatings for roofs are given towards the end of the article.
You might be wondering why and how solar reflective paint works. To understand exactly how heat reflective roof paint works, we have to start with what the coating is made of.
What Does Heat Reflective Coating Contain?
The composition of heat reflective painting is responsible for its ability to reflect the solar radiation that the sun emits. White colour heat reflective paint is made from acrylics or similar polymeric materials that have been mixed with an opaque whitened reflective pigment. These are very effective for utilizing with most asphalt roof types. This is not the only colour option to cater to individual tastes and aesthetic considerations. In some cases, the polymeric heat reflective coating can be tinted. It’s important to note that the darker the colour of the coating, the lower it reflects heat and solar radiation. The light colour heat reflective roof paint options are best for roofs.
Another option for heat reflective coating is a metallic heat reflective coating such as aluminium heat reflective coating for your roof. Metallic coatings are usually better to use when you are dealing with a rough asphalt roof. The paint coating has resins in it that are similar to asphalt. There are also some other materials mixed in with aluminium flakes. As the heat reflective coating sets, the aluminum flakes rise to the top of the coating. This creates a sold reflect top coating. The reflective properties of metallic heat reflective coating is similar to that of elastomeric coating. There is a 55% reflectance. The drawback with aluminium heat reflective coating is that the average temperature for a roof with this paint is typically higher than it is with elastomeric heat reflective coating.
How Does Heat Reflective Paint Work?
To understand the mode of operation of heat reflective coating, we must take a look at how the energy from the sun interacts with materials on earth. The sun produces energy in different forms, and these are part of the electromagnetic spectrum for radiation. Besides that, even all objects on earth including building materials and roofing tiles radiate and absorb some energy to some extent.
Some of the solar radiation coming from the sun is visible, and this is what we perceive as sunlight. Some of the sun’s rays is invisible, and this includes infrared and ultraviolet radiation. Heat reflective coating works by interrupting how energy is transferred normally between the sun’s rays and the objects and air in a room and building.
The three main ways energy is transferred is by radiation, convection, and conduction. In the case of buildings, rays from the sun can be interrupted with insulation materials, airtight layers, and other barriers between walls or between other parts of the house or other building. Radiant barriers that can be used include heat reflective coating, metallic surfaces, and other films.
White paint naturally has high solar reflectance. It reduces how much direct sunlight the roofing or building wall material absorbs.
The Impact of Heat Reflective Coating- Facts and Figures
There is a lot being said about the importance and impact of heat reflective roof paint, especially in the last few years. As we all strive towards sustainability, energy efficiency, and green living, the potential of painting the roof of your home in heat reflective paint is an option you might consider. There are several products available in this new and growing paint coating category.
Besides the potential aesthetic benefits heat reflective coating, you also have to weigh out the functional benefits, if any. The best method to do this is to consider the facts and figures and get a true reflection of the effect of coating your roofing in a new solar reflective paint. After all, there are some prices associated with recoating your roof, and you have to ascertain if these are going to be worth it both now and even in a few years.
There are lots of figures available about the impact of painting a roof with heat reflective coating. These also show that you can save a significant amount of heating cost by doing this once-off change. Here are some important numbers to take note of:
- Painting your roof with heat reflective paint can save you up to 40% on your utility bill.
- It can decrease your total energy consumption by 25%.
- As far as reducing carbon dioxide emissions, once estimates suggest that the average Australian household can reduce their contribution to this by 18 tonnes.
- Heat reflective coating can decrease the temperature of a roof by as much as 60 degrees C.
It is clear that there are some real merits of reflective paint. If you are looking for an environmentally conscious and cost-saving method to modify your home, then you should seriously consider painting your roof with a heat reflective coating. If you aren’t sure where to start, it’s time to look at some of the different options.
What is the Best Heat Reflective Paint?
If you are looking for best roof paint to reflect heat, then we have some examples of great heat reflective coating products on the market. Before you decide to use any heat reflective product, ensure that it is suitable for the type of roofing material that you have. You also have to pay special attention to any other details and specifications provided with the paint.
Dulux AcraTex InfraCOOL Technology
Dulux has come up with technology for home and building owners looking to increase solar reflection from their roofs and decrease energy bills. The new innovation, known as InfraCOOL Technology, causes surfaces such as roofs and walls to reflect visible and invisible rays. Some of the benefits of this paint include reduced air conditioning cost, leading to energy savings of 20-49%. Other advantages for home owners is increased comfort in rooms that do not have aircon as well as a lower carbon footprint.
The AcraTex Cool Roof coating product is available in both residential roof and commercial roof products. Its purpose to reflect much of the sun’s invisible infrared rays. As for its features, it is water-based, UV resistant, and has a higher build membrane.
It has many benefits including the following:
- You can coat and recoat it on the same day
- It is easy to clean up.
- The paint has a low odour.
- It is a resilient product that can withstand pollution, dirt accumulation, and chemical attack
- It is not damaged by the harsh impact of the sun.
This particular product can be utilised on roofing made from concrete, masonry, and zinc-coated sheet steel. It is for exterior use only, and should not be used to paint the ceiling or any inside walls of a building. It is made from 100% acrylic and has a 24-month shelf life. You can apply this heat reflective roof paint utilising air spray or airless spray. The clean up is easy to do using water.
There are many products in the Dulux AcraTex coating line, and these all offer some form or protection for various roofing styles. The AcraTex AcraShield Metallics products, for example, are among the newer product lines.
Another heat reflective paint option is produced by Regent Paints. It is known as Tileguard Heatguard. Its purpose is to repel solar heat. For those who are looking to get in on the environmental-conscious home improvements, using Tileguard Heatguard is a great option to save. The paint is particularly effective when used with Colorbond steel roofing.
This particular roof has insulation already and is lightweight. It has a low thermal mass and this makes it a great choice for an energy-efficient roofing option. When it is summer time, the indoor room temperatures are going to be cooler than normal. The Colorbond roofing is commonly paired with Tileguoatd Heatgurad heat reflective coating for an overall improved thermal performance.
Nutech NXT Cool Zone
This heat reflective coating option is another one worth mentioning. It is particularly good to use to reflect the sun’s radiation. You can use this paint option with asphalt, concrete, as well as terracotta tiles. Metal roofing is also appropriate. The paint 100% water-based and contains acrylic polymers. The composition of volatile organic compounds (VOCs) is also lower than many of the competitors, which is great for the environment. These chemicals are known for producing that bad odour, commonly found in paint.
The Nutech coating is 100% waterproof, which means it provides great protection during the rainy month. This innovative coating makes use of nanotechnology. These special ceramic components in the coating paint that reflect solar rays. This also reduced dirt retention.
How to Apply Heat Reflective Coating
Once you have a heat-reflective coating option that has the right properties and colour you like, it’s time to apply it to the roofing material. There are different ways to apply heat reflective coating, and it really boils down to what form it comes in, what the roofing material is like, and what the product manufacturer instructions say.
Here is a general guide on how to apply the AcraTex product:
- Utilize a two-coat application by airless spray.
- The recommended airless spray gun is the Graco Ultra 500,695,79.
- This heat reflective coat must be applied above one of these products from the same manufacturer: AcraTex Roof Sealer WB, AcraTex Roof Primer Surfacer, AcraTex Roof Sealer WB.
- The product is touch-dry within 30 minutes.
- The second coat can be applied after 2 hours.
- You can use water for the clean up.
This heat reflective coating is lead-free and forms a non-toxic fil above the roofing material. The wet film thickness is 168 (microns per coat), while the dry film thickness is 67 (microns per coat). The final result is a high build, and this means a paint-like appearance. The coating is fully cured within 7 days.
Heat Reflective Coating Thickness
As you saw in the previous section, the wet and dry film thickness of the heat reflective coating were specified for that particular product. It’s important to follow manufacturer’s guidelines about the right fil, thickness for optimal heat reflective action.
In general, the dry film thickness of a heat reflective coating ranges, starting from around 0.075mm/ 3 dry mills, which is the typical thickness of a paint film. The upper limit is over 1mm/ 40 dry mills. When you apply a heat reflective coating, this becomes the topmost layer of the roof membrane and the system beneath it. This allows the heat reflective paint to provide protection for the membrane and the entire roofing system from sunlight and its composite rays (infrared and ultraviolet), as well as from damage from rain water, hail, and physical factors.
Common Myths and Misconceptions About Heat Reflective Paint
We have looked at the many benefits utilising heat reflective coating to help your roof to reflect heat better. We have covered how this coating works and some great products that can do the job. It’s also important to address some of the most common myths and misconceptions about the impact and applications of utilising heat reflective paint. Here are a few of the myths and the science and research-backed answers to dispel them.
- Heat reflective paint for inside walls to increase indoor temperatures- There are some misconceptions about where and the heat reflective coating can be use. There’s a myth that it can be used to paint the inside walls so that the room temperature is increased. This is false, and this type of coating is only effective for outdoor use where it can get in direct contact with the light and heat rays coming from sunlight. There is no heating and cooling effect when the coating is used indoors.
- The impact of a solar heat reflective coating in the winter- ANother myth that is commonly shared is that if you paint your roof with heat reflective coating, this can get your home warmer in the cold winter months. It is believed that the reflective roof paint can keep the heat generate by your heating system inside the house. This myth is also false. The heat from the house can be is lost from the roof as normal. The reflective coating only works with the solar rays coming to it from sunlight.
Before you decide to use any particular heat reflective paint, you may want to ensure that you understand the potential benefits and know what you can expect. If you have any questions about how heat reflective coating works and why you should consider it, an expert can help you and ensure that you haven’t bought into many of the myths that circulate about this innovative technology.
There is so much to cover about reflective roof paint and all the benefits that you can enjoy when you make the switch. You may decide that painting your roofing with heat reflective paint is the ideal method to save energy spending and make your house more comfortable. Fremantle Roofing Services is a leader in sustainable roofing option & roof repair. They can assist you with making your roofing materials more sustainable.