Installing spray polyurethane foam (SPF) -based roof systems is a viable low-slope roofing option. However, many building owners, designers and roofing contractors are unfamiliar or unaware of SPF's performance attributes. Considering that SPF-based roof systems have been around since the late 1960s, SPF has managed to only capture a small share of the current low-slope roofing market.
For years, SPF-based roofing materials suffered from bad press that publicized problems associated with early installations, such as blistering, inadequate bonding between foam and coatings, and poor workmanship. However, there now are minimum standards for foam properties, improved application equipment, stringent applicator training, better design and application guidelines, and improved coatings. These improvements resulted from advanced technology, a better understanding of roofing philosophies and aggressive public relations efforts by the SPF industry.
SPF-based roof assemblies typically consist of three primary parts: roof deck and/or substrate, polyurethane foam and protective surfacing. A roof deck is the structural substrate that supports a roof system. SPF can be applied to various types of substrates, including wood, concrete, metal, rigid insulation and some existing roof membranes.