Roofs installed with FOAM (sprayed polyurethane foam – SPUF) last a very long time because it is one of the premier roofing products on the market today. While the product has favorable features, it also has some problems. The largest problem with FOAM roofing is that it is not resistant to UV light. Once it is installed at some juncture the product will fail. It will break down from UV light and start to fall apart.
Foam Roofing (SPUF) and Coatings
FOAM (sprayed polyurethane foam- SPUF) for roofs is created putting together liquid composed of two parts, which is then sprayed on to create a new FOAM roof system. The beautiful part about this product is that it is installed with varying thicknesses to develop slope so when it rains the rainwater flows to the roof’s drains. Another benefit of the product is that due to its thickness it creates R-value insulation for the building. After the foam has been sprayed over the roof, a protective coating is added for protection from UV rays, wind, snow and rain.
Here’s a breakdown of makeup of a SFP-based roof system:
- The first component of an SPF-based roof system is rigid, closed cell, spray polyurethane foam insulation. The foam is composed of two components: isocyanate and polyol. Transfer pumps are used to get the components to a proportioning unit that properly meters the two at a one to one ratio and heats and pumps them through dual hoses. The components are mixed at the spray gun, which is used to apply them to a substrate.
- The second component, the protective surfacing, typically is a spray applied elastomeric coating, though hand and power rollers can be used. The protective surfacing also can be a membrane, such as a fleece backed thermoset single ply membrane. The purpose of the surfacing is to provide weatherproofing, protect the foam from UV exposure, provide protection from mechanical damage and assist with the fire-resistant characteristic of the roof system.
- Sprayed Polyurethane Foam (SPF) roofs degrade when exposed to sunlight and must be protected by a suitable elastomeric coating system. SPF is vulnerable to UV damage if not coated within 5 hours of installation! When properly applied and maintained, SPF roofing systems should perform well for many years.
For more information on SPF, please visit the Spray Polyurethane Foam Alliance website at www.sprayfoam.org