We know that roofs bear the brunt of sun, rain, and wind when it comes to protecting our homes, but the effects of those forces are often less known. Cracking, bubbling, blistering, and general damage are all common long-term side effects of heat and water. Black flat roofs in Oshawa are no different. So how hot do flat roofs get in Oshawa and why is it important?
Heat alone can cause hefty damage over time, reducing the overall life of your flat roof and hiking up your cooling costs. Fortunately, both the costs and efficiency of flat roofs can be controlled. The first step in this process is knowing why roofs heat up.
Why So Hot?
It makes sense that roofs in Oshawa would get hot after spending so much time under the sun, but you may be surprised at just how hot they can get. An egg cooks at around 65°C, whereas a black flat roof can get up to 87°C.
The factors that go into determining roof temperatures and their efficiency are solar reflection and thermal emittance. Solar reflection describes a material’s ability to reflect energy into the sky. Thermal emittance measures how much of that energy isn’t absorbed and turned into heat. The final tally is measured between 0-1, with 1 being the coolest.
Black flat roofs absorb the most sunlight and energy, making them extremely hot, especially during the summer. Conversely, white roofs reflect more light and heat, staying cooler. The temperature of your roof affects the temperature of your home or building a lot. With a cooler roof, the cooling power you need vastly changes, even allowing you to size down if you’re buying and installing a new air conditioning system.
The differences between flat roof materials
Several different materials are used for black flat roofs in Oshawa. Here’s a quick list:
- Black Roofs (tar, rubber, black shingles)
- Gravel (layers of tar & other materials, topped with gravel)
- White Roofs (TPO or PVC, membrane roof)
- Metal Roofs (painted/coated)
- Vegetative roofs (green roofs)
The differences between materials lie in their coolness and efficiency. A white roof will keep the building below it much cooler, even during the summer months. Coated metal roofs also reduce heat absorption.
Vegetative roofs do the best job at this, and they’re the best roofs for the environment and the atmosphere. The material you go with will likely depend on costs and efficiency. While there’s no wrong answer, it’s good to know just what you’re getting into before installing a new flat roof or having an old one replaced. Here are those materials in greater detail, listed from hottest to coolest.
Black Roofs (60-87°C)
Black flat roofs are typically made from tar, rubber, or dark shingles. The dark colour of the materials absorbs quite a bit of heat and energy, which in turn heats everything below it. Black roofs will feel very hot to the touch (hot enough to cook an egg!) and they aren’t renowned for being particularly long-lasting.
Heat damage can take years off the life of black roofs, as heat can cause blistering, expansion, and cracks that eventually cause early replacement. (You can always call CD Roofing for flat roof repair and maintenance if that ever happens!)
Gravel Roofs (51-60°C)
Gravel roofs are significantly cooler than black roofs. Though they are made with tar and other materials, the layer of gravel on top helps prevent as much heat absorption as black roofs. These roofs are heavy, though, and may not be suited for all applications.
White Roofs (38-48°C)
White roofs are made from TPO, PVC, or other membrane materials. The aspect that sets them apart is their colour-white. We’re familiar with the cooling power of white, like wearing a white shirt compared to a black one, and this extends to roofs, too.
More light is reflected rather than absorbed, which lowers the temperature of the roof and the space below it. Whole buildings can become more efficient with a cooler roof, whether they’re commercial or residential.
Painted Metal Roofs (40-46°C)
Metal roofs that have been painted or coated with reflective materials are significantly cooler than untreated metal roofs (by 30º or more). Metal sheeting is usually used for these roofs, which are painted before installation. It can also be painted after installation if you’re looking to upgrade the efficiency of your already-existing metal roof.
Vegetative Roofs (32°C)
Vegetative roofs, or green roofs, maintain the outdoor temperature around them-no heating up. On a 32° day, a vegetative roof will also be 32°. These organic roofs have the benefit of constant shade, as the roof itself is covered by plants and thick vegetation. The vegetation absorbs sunlight, uses it for photosynthesis, and guards the roof against the damaging effects of heat. This is beneficial for the roof and the environment, as less energy and heat are reflected into the atmosphere and air.