According to Wikipedia, roof coatings are "a monolithic, fully adhered, fluid applied roofing membrane. It has elastic properties that allows it to stretch and return to their original shape without damage." These coatings are based on four different types of materials that work in different situations. If spray foam is needed to increase insulation value or to add tensile strength to a roofing system, one of the coating systems must be used over the foam to protect it from UV radiation. These coatings can also be used alone as a restoration material over most commercial flat roofing systems with the use of the proper primers, and/or fiberglass membrane for reinforcement. This process provides a lower cost alternative to a full re-roof of almost any flat roof.
The first type of coating material are acrylics. These products are water based and are generally less expensive then the other coatings, making them the most cost efficient coating system on the market today. Although they can be done in custom colors, white is considered to be the choice in most situations due to it reflective properties in "Cool Roof" systems. The cons of Acrylic are that it is not grease resistant and looses some mil thickness due to weathering. If you don't use us as your contractor, make sure enough mil thickness is applied to last through the life of the warranty/maintenance cycle.
The second type of product is Urethane coatings. This material is a solvent based material that is slightly more durable than the acrylic coatings in some instances. The cons of the urethane coatings are their cost is higher thane the acrylic's and it is not as UV resistant. In many Federal Government specifications for Spray Polyurethane Foam and coated roofs, they use the urethane's as base coats, and then cover it with an acrylic coating to stop the UV degradation. This drastically increases the system cost. Because of the high UV radiation in the Denver area due to be closer to the sun, we do not usually recommend the urethane coatings for Colorado.
The third type of elastomeric product are silicon based. These products are solvent based and are cured by moisture. They can be used at lower temperatures than the acrylics which makes them more useful than the acrylics in the late fall and early spring and on warm days in the winter. Silicons weather better thane the other coatings with almost no erosion and never get hard or brittle. Warranties on these systems can also be obtained for longer periods than the other systems. They are only slightly more expensive than the acrylics. The negatives are that silicon gets dirty easier, which makes it loose it's reflective properties sooner. It can also tear easier than the other coating systems with foot traffic or extreme weather. Also, silicone is slippery than the other coating systems. This results in two issues. First, when it is time for re-coating the roof, you either have to tear off all the coating, or re-coat with a compatible silicon product. It also can be very slippery when wet. Unless granules are added to the roofing process, care must be taken if roof work needs to be performed by other contractors for HVAC, plumbing, electrical or satellite dishes.
The fourth and newest addition to the coating line are the synthetic rubber materials. These materials are quite resistant to foot traffic, hold their reflectivity well since they are more of a semi-gloss than a flat paint look. They also in our experience work very well for sealing areas of roof leaks. They work exceptionally well for metal roof restoration projects and are working well over Spray Polyurethane Foam roofing material. The negatives at this time are they cost more than the acrylics and silicons, and currently are not produced by the major roofing manufacturer's. For this reason full system warranties of spray foam roofing are not available, however, the manufacturer's warrant the coating product and Colorado Thermal Coatings, will warrant the foam work for the same periods as the coating warranties.
There are many choices when it comes to coatings, but all are cost and energy efficient and can be a good solution instead of a full roof tear-off and replacement.
Call us at 303-886-5331 for a free roof inspection and let us walk you through the options available. Or you can use our simple contact form.