Adding a coating to your commercial roofing system is typically done for the following reasons:
- To protect the substrate from heat absorption or UV degradation
- Improve aesthetics
- Increase energy efficiency
In order to achieve the desired appearance and performance of the roof coating as well as the entire roof system, it’s important to maintain proper coverage rates. Too much paint can cause the coating to crack as it dries or blister because of trapped solvent. On the other side of the coin, too little paint may not be enough to sufficiently cover the roof surface. This can cause the coating to underperform, which may require the surface to be re-coated sooner than expected.
Check out the two photos below to see the difference between one and two coats of Pyramic on a roofing system. You can easily see that with just one coat, the system will not provide the surface reflectance specified on the data sheet, nor will it protect the roof system from UV damage as well as a system with the proper amount of paint.
The two pictures below show two different views of the same roof. The close up photo shows cracking right next to an area that did not crack. In the second photo, you can see a pulled away shot of the same roof. This photo shows shading caused by an uneven coverage rate. This is what led to the cracking of the coating that you saw in the first, zoomed-in photo.
However, it’s not enough to simply have one coverage rate for a wide variety of roof surfaces. There are different coverage rates for smooth or mineral cap sheets because of the surface irregularity of the sheets. The photo below shows a zoomed-in view of a mineral cap sheet that was painted. The texture means it takes more paint to cover the surface than a smooth cap sheet.
For Garland roof coatings, the coverage rates are as follows:
Pyramic should be spray, brush or roller applied at a rate of 1 gal./100 sq. ft. over smooth modifieds (0.41 l/m2) and 1.5 gal./100 sq. ft. over mineral surfaced modifieds (0.61 l/m2). For best results, apply a two-coat application in a crosshatch manner, or install one coat of Pyramic Base Coat prior to installing Pyramic as the top coat.
Solex should be spray, brush or roller applied at a rate of ½ gal./100 sq.ft.(0.21 l/m2) over smooth or mineral modifieds with a base coat of Pyramic Base Coat applied at a rate of 1 gal./100 sq. ft. over smooth m odifieds (0.41 l/m2) and 1.5 gal./100 sq. ft. over mineral surfaced modifieds (0.61 l/m2).
Garla-Brite should be brushed or roller applied at a rate of ½ gal./100 sq. ft. over smooth modifieds (0.20 l/m2) and ¾ gal./100 sq. ft. over mineral surfaced modifieds (0.30 l/m2). For best results, apply a two-coat application in a crosshatch manner.