Spray polyurethane foam roofing (SPF) is an increasingly popular roofing system because of the many benefits it provides. SPF can be sprayed as a liquid over existing low-sloped and flat roofs or underlayment. Once coated, the closed-cell foam will harden and expand. There are several advantages and a few disadvantages to choosing SPF roofing. Is it the right coating for your business? Here are the pros and cons to help you decide.


Energy Efficiency

SPF is a popular roofing system in part because the foam acts as an additional layer of insulation on your roof, increasing energy efficiency. SPF has a high thermal resistance and that helps regulate the building's internal temperature with minimal changes due to outside air temperatures.

Additional Waterproofing

SPF is sprayed onto an existing roof or underlayment in one continuous layer with no overlapping sheets or seams. That means there are no spots where water can penetrate the coating. Additionally, when installed by expert installers with previous experience with SPF, the system can help prevent standing water.

Low Maintenance

Once installed, SPF requires very little maintenance. If a problem arises such as a tear or a leak, it can be easily repaired with additional spray foam.

Wind Uplift Resistance

Because SPF forms one continuous layer, it has enormous resistance to wind uplift. There are no fasteners or ballast to catch the wind and come loose. 



One of the disadvantages of SPF is the preparation involved. The roof must be free of anything that would prevent the foam from adhering to the roof, including dust, dirt, oil, adhesives, etc. Depending on the condition of your existing roof, that preparation may take some time and labor.

Weather Conditions

Another drawback of SPF is that it needs ideal weather conditions for installation. It must be a clear day with no rain in the forecast. Additionally, the temperatures must be warm for the foam to set properly. If you live in a wet and humid climate, finding the right installation window can be tricky. Also, any wind can result in overspray to nearby structures or cars so it can't be installed on a day with high winds.


It can be difficult to predict a random gust of wind even on the clearest days so it's important to anticipate accidental overspray and remove any structures or vehicles near the installation site to avoid problems with unintended overspray.

Contact a local roofing service to learn more about foam roofing system installation