Cool roofing systems are roofing systems that can reflect visible, infrared and ultraviolet wavelengths of the sun and can release a large percentage of absorbed heat. As a result, heat transfer to the building is reduced. Cool roofs fall under one of three categories: inherently cool, green-planted roofs, or coated with cool material.
Inherently Cool Roofs
In this category, roof membranes are made of white or light-colored materials that achieve the highest reflectance and emittance measurements. For example, a roof made of thermoplastic white vinyl can reflect 80% more of the sun’s rays and emit 70% of the solar radiation that the building absorbs. On the other hand, an asphalt roof can only reflect up to 26%, which results to greater heat transfer to the building interior.
A green roof is a roof that is partially or completely covered with vegetation that are planted over a waterproofing membrane. It consists of many layers that include the insulation layer, a waterproof membrane, a drainage layer, a growing medium, plants, and sometimes a wind blanket.
Green roofs are either intensive or extensive. Labor-intensive roof gardens require a reasonable amount of garden soil while extensive green roofs are almost self-sustaining.
If there is already an existing roof or a new roof needs to be roof reflective, roofers apply a specifically designed white roof coating on the surface of the roof. The coating has to be Energy Star rated.
There are many benefits to using cool roofs. It reduces a building’s heat gain, enhances life expectancy of the roof membrane and the building’s cooling equipment, improves thermal efficiency of the roof insulation, reduces the demand for electricity by 10%, and reduces greenhouse gas emissions and air pollution.
Call Montgomery Contractors, Inc. today for a free estimate at (910) 220-2172.