Spray polyurethane foam (SPF) roofing systems have been successfully deployed to protect buildings against Mother Nature's worst: hurricanes, tornadoes and other high-wind disasters.
So, why don't more people use it?
Here are 8 misconceptions about the use of the foam plastic product in roofing systems.
#1 - Foam Roofing Is New
As a product, polyurethane foam has existed for the better part of a century, and it has been in use in roofing applications for about half a century. For most of the modern living world, foam roofing is most definitely not new.
#2 - You Can't Walk On A Foam Roof
On the contrary, you CAN walk on a foam roof; and you don't even need the skills of a ballerina or ninja to do so! Just leave your high heels and cowboy boots in the truck, because it's best to use soft-sole sneakers. Unless you're walking on a condemned (or soon to be) building, a foam roof is completely capable of sustaining the weight of a normal person.
#3 - Foam Roofing Material Is Just Like Foam Insulation Material
The closed-cell polyurethane foam used in roofing applications is a completely different material than interior foam insulation. The polyurethane foam used for roofing applications is much stronger and more durable than interior foam insulation, and meets all testing standards.
#4 - Foam Roofing Is Expensive
If you're only considering a 5 to 10 year window, a spray foam roof may or may not be more expensive than other roofing options. However, when you start evaluating 15 years or more, the foam roof becomes much more cost effective than other alternatives.
#5 - Spray Foam Roofs Are Not Durable
When you think about "tough" materials, foam products probably don't come to mind. However, many of the earliest foam roofs are still standing strong. - 50 years and counting! - Foam roofing has already stood the test of time, and it's a fact: a foam roof can last the life of your building.
"One of the most famous examples is the New Orleans Superdome. A severe hailstorm damaged areas of the SPF roof in 1978, and the city debated for the next 10 years on how best to execute repairs. Finally, in 1992, the roof was repaired and re-coated. Despite such a long time before repairs were finally carried out, the roof never leaked from the hail damage. (In truth, some leaks were reported, but those were caused by bullets fired at the roof during Mardi Gras.)" - [Knowles, Mason "Sustainability Characteristics of SPF Roofing & Insulation Systems"]
#6 - Foam Boards Insulate As Well As Spray Foam Roofs
Although the R-Value of a foam board roof appears to be on par with a foam roof, the actual performance of such roofs is substantially inferior. More specifically, the R-Value of the insulation does not factor air-infiltration with thermal resistance, which makes it an inaccurate comparison.
#7 - Polyurethane Foam Is Toxic
Polyurethane foam is really just a form of altered plastic with millions of tiny trapped air bubbles. Although the formulation is designed for roofing applications and optimized for the best combination of thermal resistance and durability, polyurethane foam materials are completely inert, and are just as safe as the foam pillows you probably have on the couch in your living room or the seat cushions in your car.
#8 - Spray Foam Roofs Absorb Water
Spray polyurethane foam used in roofing applications is "closed-cell." In other words, it is a plastic with millions of tiny closed cells which are impenetrable by water. A block of closed-cell SPF submerged under water will remain buoyant and dry indefinitely. If foam on a roof system is found to soak up water, either the wrong material was used or the material components were not applied properly - both a result of applicator error.