Most commercial buildings are so large that building a sloped roof is not feasible. Thus, they will use a flat roof. The most common and least expensive material used to create a watertight flat roof is a BUR roof, which is made from alternating layers of tarpaper and asphalt tar. As such, flat roofs are black and readily absorb heat from the sun and then conduct that heat into your building. To reduce cooling costs you should use a white roof.
Why White Roofing Materials Are Better
The color of an object is based on how much of the sun's light it reflects. Thus, a blue object absorbs all of the sun's rays but those in the blue spectrum. A black object gets its color by absorbing most of the sun's rays. The more light an object absorbs, the hotter it gets. White objects get their color by reflecting most of the sun's light. Simply by covering your roof with a white roofing membrane, you can keep your roof cooler, and thus keep the building below it cooler. In fact, a white roofing material can reduce your cooling costs by up to 20%.
How to Create a White Roof
There are a few different options available for creating a white roof. For one, you could use a white gravel to cover your asphalt tar. If you have an existing BUR roof, this is probably the least expensive option. The drawback to using gravel on a roof is that it can shift around and therefore may not evenly cover your roof. You could also use a rubber roofing membrane with a white surface to cover your roof. You can use this option to either cover an existing BUR roof or create a roof for a new building. Rubber roofing membranes typically cost more money to install than a BUR roof, but they reduce the number of seams in your roof and the membrane itself will resist leaks better than a BUR roof. Thus, if you have the money you should opt for a rubber roofing membrane.
While using a white roof will increase your installation costs, you will save money from month to month on your cooling costs. Thus, you will save more money than you spend on installation. For this reason, a white roof is the most cost-effective solution for covering a roof. Talk to a roofing contractor like Empire Roofing to learn how much installing a white roof will cost and how much you stand to save from month to month.