The trend lately has been to go green when building a structure, but it seems that architects are stuck in the past when it comes to the type of flat roof that is installed. Maybe they do not know about the new, environmentally friendly, white roof option, or maybe they are stuck on tradition and afraid to change. No matter what they think, you have an option to have your roof installed using white materials that reflect the sun and reduce cooling costs. But, are they a really good option for a cold climate like we have here in Ontario?
Architects argue that a black roof attracts the sun’s rays during the day and heats the inside of the building on cold days thus reducing the heating costs in the winter. This is a definite benefit but do the savings really add up in the long run. After all, it costs more to cool the building in the summer with a black roof as it attracts the sun’s rays summer and winter. So what is best for our climate here?
In the winter months, the sun is lower in the sky so the energy emitted by the sun on the roof is indirect, whereas the summer months the sun is higher and the rays shine directly onto the roof. The days of winter are also much shorter, and in a snowy climate, the roof is usually covered in snow, which is white.
Using some common sense tells us that the sun is hottest during the summer months and having a black roof will attract the sun’s energy and heat up the interior of the building much more than it does in the winter months. The black roof also retains heat, which is why most flat roofs are covered in gravel or other material that does not absorb heat as much as the tar on a black roof. Sometimes, white granules are placed on top of the tar to help reduce the amount of energy that is absorbed, but this is counter-efficient as you are paying to fix a problem created when the black roof was installed. You wouldn’t shingle your house with new shingles then put a tarp over it to protect the shingles would you?
We are not saying that black roofs are bad. We install them all the time and are quite popular and necessary in some situations. But, when you are given an option, you should not turn your back on the environmental choice of a white roof. There are instances where the total energy savings over the life of a white roof exceed the total cost of installing the roof, so it makes sense to go with the white roof to start with.
Now, when you look at the new rules that have come out for energy usage, you will notice that the highest premiums for energy are during the daytime when the sun is out. So, why not utilize the sun and your roof to take advantage of lower energy costs.
So, what does all this mean? You will save more money on cooling costs in the summer by having a white roof than you will save on your heating costs by having a black roof in the winter. Now, not all white roofs are created equally, and some situations require a different approach so it is best to speak with your roofing expert to find out what option suits your needs. There are many options available and one that suit your needs and budget.
Contact Essential Flat Roofing for all of your roofing needs!