What is Spray Foam?
In the newest entry in our “What is a Substrate?” series, this week’s blog will answer the question, “What is Spray Foam?”
Spray polyurethane foam (SPF), better known as spray foam roofing, is made up of the liquid chemical compounds isocyanate and polyol and other additives. Together, isocyanate and polyol form the base of SPF. It is applied onto the roof deck as a liquid, then expands into foam as it dries and conforms to the surface.
SPF has been a popular choice for flat-roofed residential and commercial buildings thanks to various factors. This blog will look at spray foam’s advantages and disadvantages and how Progressive Materials’ silicone roof coatings can help when SPF falls short.
One of SPF’s biggest advantages is that it’s an excellent insulator. That can help a building owner reduce heating and cooling costs. A foam roof can usually pay for itself in two to six years in energy savings alone.
SPF also effectively seals against leaks. It can be sprayed on surfaces with irregular shapes and penetrations and make them watertight. It coats and effectively eliminates seams, eliminating a common point of roof failure.
Spray foam is also a lightweight material, which can make it easier to install than many traditional roofing materials.
Last but not least, spray foam roofs are durable. A properly installed spray foam roof can last at least 20 years.
The most pressing disadvantage of spray foam is that it cannot handle the sun’s ultraviolet rays. Within 72 hours, uncoated SPF will begin to deteriorate. And under direct sunlight, SPF will degrade at a rate of 1/16th inch per year.
Additionally, SPF can only be sprayed when it’s at least 50 degrees. For roofing contractors, especially those in the colder northern states, that creates a smaller window of opportunity to use spray foam.
The final disadvantage has little to do with the product itself. The application process for SPF is strict, and some contractors fall short. They may spray foam in weather conditions under 50. They may incorrectly mix the spray foam materials. Or they may install spray foam over wet insulation. Any of these errors could lead to an incorrectly installed SPF roof and a costly do-over.
How PM Can Help
We noted earlier that SPF degrades quickly amid exposure to the sun. That means an SPF roof must be coated with another material that can protect it from those UV rays.
PM silicone is often used to coat SPF roofs because of its excellent weather-resistant qualities. While SPF degrades in the sun, PM silicone reflects nearly 90% of UV rays on your flat roof. That limits the damaging effects those UV rays can have on your building.
If you use PM’s white silicone, this can lower the building’s internal temperature if the current roof is a darker color. Additionally, the seamless silicone membrane leaves nothing to be broken down by UV rays.
While SPF application is limited to days exceeding 50 degrees, you will face a much wider application window with PM silicone. As long as you can keep the material and hoses warm enough, you can apply the silicone and it can adhere.
In terms of application, PM has strict rules for who can become a PM Certified Licensed Applicator. Contractors interested in offering product warranties through PM must become a Certified Licensed Applicator.
In conclusion, we believe its strong insulating qualities and other factors make SPF roofs good choices for low-slope and flat commercial buildings. But spray foam cannot stand alone due to its inability to handle UV rays.
A top coat must be added to protect SPF, and PM silicone is a great choice due to its weather-resistant qualities, wide application window, and other factors.