Wednesday, July 6, 2011

Longevity: Another Benefit of White Roof Coatings

A typical building in the ancient Mediterranean - everything but the wood is coated white.

Lower energy use isn't the only benefit of white roof coatings like those from Conklin - they can also extend the life expectancy of many different types of roofing systems simply by avoiding the high roof temperatures associated with exposure to the sun (the technical term for exposure is “insolation,” measured in terms of the rate of solar radiation received per unit area).

Heavily insulated roof systems block this heat from penetrating the building as heat, but in summer months convective heat transfer to the surrounding air and radiant heat transfer are inefficient. Consequently, the heat has nowhere to go and roofing membrane temperatures can soar.

High temperatures can shorten the life of the roofing system. Rubber as well as other synthetic polymers and especially asphalt is susceptible to damage after prolonged exposure to elevated temperatures. Roof temperatures can rise above ambient air temperatures by as much as 90°F, accelerating the rate of degradation of the roofing materials - especially when the roof surface rises to 140°F and above. Significant damage can begin to occur at these elevated temperatures, causing both short-term and long-term performance issues. A rule of
thumb for thermal aging is that service life is cut in half for every 18°F increase in temperature (weighted and averaged over time).

Most people appreciate that white roof coatings result in savings on cooling costs, but enhanced roof longevity (especially in northern states) can be another major benefit that results in at least as much savings. Without white coatings, roof temperatures can skyrocket in the summer months (especially for buildings in cooler climates) because they typically have a lot of insulation to help keep in the heat during the winter months.

COST SAVINGS: The inverse correlation between insulation thickness and roof life is well documented by roof asset management firms. Since ripping out the insulation every summer is of course impractical, white coatings are one of the best means available to counteract the deleterious effects of high heat levels and enhance the prospects for a long-lasting roofing system.

Please also see the September 2006 article by Tom Meyer and Steve Heinje titled "Cool Roofing: Coatings Keep Things Cool".

Tired of labor problems and low profit margins? Make more $$ spraying coatings with Conklin Roofing Systems! Patton Services | (309) 303-3128 | |

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