What is Sprayed Polyurethane Foam?
Sprayed Polyurethane Foam is a combination of isocyanate and polyol. These two components are fed through a proportioner which heats then pumps the two separate components to the spray gun, where they are mixed and sprayed onto the substrate. Because it is sprayed onto the roof as a liquid, it forms a single continuous structure that is seamless and very stable. SPF requires a clean surface for proper application. It must be dry, free of contaminants like oil, and properly fastened to the substrate in accordance with the proper building codes. A protective elastomeric top coat is required which is typically sprayed on as well, but it is also possible to be applied with hand or power rollers.
Foam roofing has many advantages over traditional roofing methods, and as you read through this web site you will learn a lot more about them. Here are some brief examples:
- Seamless: Polyurethane foam is applied as a liquid, creating a single monolithic membrane that covers the entire roof. There are no seams or joints, the source of the majority of leaks in traditional roofs.
- Flexible: The foam can be sprayed onto virtually any surface, irregularly shaped roofs and protrusions are readily taken care of.
- Lightweight: Foam roofing typically weighs around 50 lbs. per square, versus 800 lbs. for a built-up roof and 100 lbs. for ballasted single-ply roofs.
- Thermal Insulation: SPF has the best insulating properties available for commercial construction today.
- Sustainability: Foamed roofs require a minimum of upkeep, creating little waste and have an indefinite lifespan.
Sprayed polyurethane foam has an R-value of 7.14 per 1 inch thickness, enabling it to provide more thermal resistance with less material than any other type of roofing insulation.
Foam roofing produces energy savings of 30% or greater when compared to the alternative roofing systems. The cost of the roof can be easily recovered in less than 5 years, simply through these energy savings alone!
SPF systems are frequently used to insulate and protect a wide variety of special structures. It has been used with great success in the oil industry, chemical process plants, even in the wine industry.
Sprayed Polyurethane Foam is perfect for many different waterproofing applications. Because it is composed of billions of closed cells, the foam acts as an air barrier, preventing moisture infiltration into the building. This ability minimizes dew point problems, which unchecked leads to water condensation inside of the structure. Moisture infiltration into the building envelope is the number one cause of building deterioration.
Even when the top coat of a foam roofing system is damaged, the underlying foam will keep the roof from leaking. The Superdome in New Orleans was damaged once in a severe hail storm. Thousands of hairline cracks appeared in the top coat, but no leaks ever occurred, even though it wasn’t repaired for over a decade!
If a penetration does occur all the way through the foam layers, the water infiltration will be isolated only to the area where the membrane has been penetrated. Small penetrations in foam roofing systems can be repaired easily with an elastomeric caulk, reinstating the integrity of the system.
Water ponding is quite often a problem with conventional roofing systems. When applying the polyurethane foam in reroofing situations, it is very easy to build up areas of greater thickness while spraying. So that water will drain properly. This also eliminates the problem of the additional weight load associated with water accumulation.