Cool Flat Roof: What you need to know.

Posted on

What is a cool roof?

A ‘cool roof’ is one that is made to reflect more heat, and UV rays from the sun, than a standard roofing system. The drawback of having a flat roof, whether on your home or business, is the amount of heat it collects. This heat can seep into your home, and cause a significant increase in the cost of your energy bills. A cool roof helps to reflect a lot of that heat back into the atmosphere. The thought is the same as you wearing lighter coloured clothing in the summertime, to keep cooler when outside. Cool roofs can be installed in many different forms, such as white or light-coloured coatings, PVC coverings, and reflective metal. Having a thin layer of solar panels on your roof top can also help to control the heat absorption. A regular, or standard roof can reach temperatures of over 100 degrees Fahrenheit. While a ‘cool roof’ placed under the same stress can remain at a temperature less than half of that.

The Benefits of a Cool Flat Roof

As stated above, energy saving is a huge pro for this type of roofing system. As flat roofs do tend to collect more heat from the sun than the standard roof. Using these shiny materials will prevent a large portion of the suns heat, and UV rays, from passing through your roofing material. Having a cool flat roof installed onto your home or business also helps to reduce greenhouse gases and improve general air pollution. Cool roof coatings can also reduce peak energy use, by about 10%. In addition to energy saving, having a cool roof installed will also help to improve the level of comfort that you feel in areas with no air conditioning, like a garage or covered patio. One huge pro for this type of roof is how much it can benefit the health of your entire roofing system. Heat, and UV rays can cause a significant amount of damage to your roofing system, reducing its lifespan significantly. As a cool roof reflects most of these rays, it is actually acting as an extra layer of protection for your roof. Because your HVAC system is not required to work as hard, you can also expect to save on flat roof repairs and replacements, as its lifespan should be prolonged.

The Issues with a Cool Flat Roof

As far as energy saving, and roof protection, cool roofs can be incredibly beneficial, though they are not without their share of problems. Because of the materials used, algae growth can become an issue with cool roofing systems, more so than with a standard or ‘dark roof’. Most times the cool roof will be sprayed with a special coating to prevent this, but most only last for a few years before the coating will need to be reapplied. Cool roofs do tend to be more beneficial in warmer climates, and they can sometimes end up increasing energy costs in the wintertime, as all heat retention is lost. How beneficial a cool roof will be to you will depend entirely on the climate in which you live, the amount of attic insulation you possess, the efficiency of your HVAC system, and what type of roofing system you have currently.

How Can I Make My Flat Roof Cool?

There are many light-coloured coatings available to help convert your current roofing system into a cool one. Installing a shiny metal on your roof top, covered in the necessary coatings, can also turn your dark roof into a cool roof. If your roof is in good condition, there are many reliable sprays and coating that can be used to protect and cover your existing materials. However, if your current roofing system is in poor condition, it would be far more cost-effective to completely retrofit, or replace it. Green roofs are also an option when considering making your roof ‘cool’, though this can be incredibly costly and time consuming. With the right materials, and competent installation, you can help to reflect almost 80% of the suns damaging UV rays back into the atmosphere. Thus, lowering your household energy use, and helping to reduce the temperature in your neighbourhood as well.