When it comes to performance and longevity, few commercial roofing materials are superior to spray polyurethane foam (SPF). The material boasts impressive insulative and waterproofing qualities, while also improving interior comfort and energy efficiency. Read on to learn the basics of foam roofing.

Spray Polyurethane Foam (SPF)

A plural-component material, spray polyurethane foam is created by blending polyol and isocyanate with pressure and heat. Sprayed in liquid form, the two chemicals react on contact to create a lightweight, solid and fully adhered membrane. As it cures, the foam solidifies to form a seamless, waterproof, durable membrane. SPF provides the highest R-value (thermal resistance) of any known commercial roofing material and is well-suited for virtually any climate.

While it’s been around for quite a while, spray foam is still relatively unknown to many commercial property owners. SPF has been used for various applications in diverse industries since the 1940s, but it wasn’t until around 40 years ago that the roofing industry began to appreciate the material for its versatility and superior insulative qualities.

Modern foam roofing materials come in closed-cell and open-cell grades. Open-cell foam is usually used for soundproofing and interior insulation. Closed-cell foam, on the other hand, is typically used in commercial roofing applications.



Spray foam has the highest thermal resistance of any conventional roofing material. Its high R-value indicates that it has a superior ability to resist the flow of heat and provide impressive insulation qualities compared to other roofing material options.


Remarkably lightweight, spray foam roofing is incredibly strong. In fact, when applied at a thickness of at least 1 inch, SPF systems are capable of enhancing a commercial building’s structural integrity.


A properly installed and well-maintained foam roofing system can last three to four decades; although it should be recoated every 10 to 15 years to combat UV degradation.


Unlike traditional roofing systems, spray foam is completely seamless and self-flashing. This all but eliminates the risk of water penetration.


Foam roofing systems are very easy to maintain. Minor damage can usually be repaired using specialized roof sealant or roofing-grade mastic.


SPF can be installed much more quickly than conventional roofing systems. This is because the material is applied directly to roof substrates without requiring the removal of existing roofing materials.


Since foam roofing systems can be recoated many times, they produce very little waste throughout their lifespans. This minimizes waste concerns and the high costs associated with a complete roof tear-off and replacement. The materials used in spray foam roofing systems are also eco-friendly.

spray on roofing

The Disadvantages


Spray foam roofing requires expensive application equipment. While most spray rigs cost around $10,000 to $20,000, a spray foam rig can cost as much as $100,000.

Up-Front Cost

When it comes to cost, spray foam roofing systems are fairly comparable to many other commercial roofing options. That said, they are more expensive than most roof coating systems. In the long run, these costs are usually offset by low maintenance, long lifespans and high performance.

Limited Application Windows

Foam roofing must be installed when humidity is low and temperatures exceed 50°F. Depending on the region and season, this can delay or even prevent installation.

UV Exposure

Although foam roofing is incredibly sturdy, it isn’t designed to hold up to prolonged sun exposure. Routine service and regular re-coating every 10 to 15 years are needed to prevent premature system failure due to ultraviolet light.

Application Issues

There is always a potential for overspray when applying foam. One of the best things about SPF is its strong adhesive qualities. While this is great for the roof, it’s not ideal for other underlying surfaces, such as landscaping, cars and neighboring structures.

Spray Foam Roofing: Leave it to the Pros

When it comes to applying a spray foam membrane, not all roofers are created equal. Working with spray foam requires a high degree of experience and product knowledge. If you’re interested in an SPF roofing system, you’d be well advised to practice due diligence and find a properly trained local roofing contractor.

Need help applying a spray foam roofing system? For decades, the professionals at A to Z Roofing have served countless satisfied customers throughout the Denver metro and the Front Range. For nearly a quarter of a century, we have been the go-to source for expert residential roofing, repair and restoration for homeowners and businesses throughout Colorado. During this time, we’ve provided comprehensive service using only top-quality products. Contact our attentive team to schedule a free estimate, and learn how we can restore, repair or replace your damaged or aging roof.