Direct compliance, method four (NFPA 275, also known as “equivalent thermal barriers”), is a test protocol that requires both tests—the temperature transmission test and the flame spread smoke generation test—both over a period of 15 minutes. Method four establishes a combination of both the prescriptive solution and the special approval solution and defines an equivalent thermal barrier to the gypsum prescriptive method.
All of these choices relate to a life-safety and liability issues; therefore, it is imperative for the builder, architect, or general contractor to understand the various fire-rating methods and what they mean in order to protect themselves. Alternatively, find a trusted compliance partner, a fire consultant, or a fire inspector.
The SPF insulation industry has not been standing idly regarding the emerging requirements and changing code needs. It is finding ways to improve fire resistance. It is proving compliance to environmental/sustainable/planet-saving initiatives. SPF is the best solution for addressing the challenges of less CO2 emissions and less energy losses in buildings, which are one of the largest contributors to global warming.5 Post-applied thermal barriers and cost increases associated with them have made the expansion of standard SPF into broader markets slowly. New, all-in-one thermal barrier sprayfoam technologies help solve many of these challenges, and effectively provide better value.
Emerging sprayfoam insulation technologies
Monolithic fire performance
Some emerging SPF products are striving to achieve better fire performance, monolithically, in foam insulation. These new, monolithic SPF products pass NFPA-275 thermal barrier tests, thus being thermal barriers and c.i. Since the foam is a composite homogeneous solid, when it meets NFPA-275 requirements, it is a fire and thermal protective barrier throughout the complete volume of the insulation all-in-one. Having its fire characteristics throughout its complete volume means fewer added steps, cost, and risk, versus a thermal barrier coating, cellulose, etc.
Post-applied “exception-based” thermal barriers become daunting when trying to ensure compliant, safe application. First and foremost, they need to be properly applied. Second, proper application requires third-party inspection. Next, they can only be used in what is referred to as “conditioned spaces,” which are dry, heated environments lest they are prone to field failures. Finally, as soon as the surface is breached in any way, shape, or form, the fire barrier characteristic of the flammable substrate is lost.
A monolithic fire barrier material will also protect against fires from the outside in, as well as fires from the inside out. Topcoats only protect one face of flammable insulation; they cannot provide unilateral fire protection from wildfires (externally initiated fires), electrical shorts, wall fires, lightning strikes, etc.
