ADVANCED ROOF COOLING PAINT
How Long Will It Last?
Degradation of reflective roof coatings is of practical concern because their high-albedo property is primarily responsible for the cooling-energy savings.
Moreover, cooling roof coatings may have good longevity when applied properly. For example, a five-year old swatch of an elastomeric coating applied to the cupola roof of the FSEC`s Passive Cooling Laboratory still showed a laboratory reflectance of 0.73–very close to the initial properties of such samples (0.70-0.79) The reflectivity of the roofs in FSEC’s experimental homes was measured seven months after the coatings were applied.
However, some minor stains due to disintegrated leaves and dust were evident at Site #1, whereas no signs of degradation were in evidence on the flat roof at Site #2.
In addition, the average of the measurements at Site #1 indicated a reflectance of 0.69 with greater variation in the readings over the roof surface.
The tested reflectance at Site #2 was 0.73, however, Although both aged values were lower, a statistical test of the means revealed no significant differences in the data taken immediately after the coating were applied and those obtained seven months later.
More recently, however, FSEC examined the roofs at Sites #1 and #2–18 months after they were coated. Although the flat roof at Site #2 still showed little sign of weathering, some staining was becoming apparent on the coated asphalt shingles at Site #1.
The research
The most significant research on the longevity of cooling coated roofing systems was also performed recently at LBL.
Furthermore, this research examined 26 spot measurements of aged “high albedo” roofs of various types and found that most of the weathering and reduction in solar reflectance occurred in the first year after application or even within the first two months.
However, for a gravel coating the albedo was reduced by 8% over six years, but 6% of the drop occurred in the first year.
Furthermore, other reflective roofing types experienced reductions to albedo of up to 24%. In addition, The LBL researchers also experimented with washing cooling roofing systems, and found that it was possible to restore roofs to 90% of their initial values.
Figure 1a, Air conditioner use and interior air temperature before and after a cooling roof coating is applied at site #3.
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Cosmo-Dec Everlasting Coatings originated in 1991, with a single product – Therma-Masta™.
Knowledge gained from manufacturing this complex and unique product allowed us to formulate new and innovative products such as Fire-Guard™, Aqua-Mite™, Aqua-Therm™, Clean-Air, etc. for specialty applications.
To-day, 3 decades on we manufacture more than 80 different types of construction chemicals out of our factory in Pretoria, Gauteng.
