Undoubtedly, the most important coatings used in the spray polyurethane foam industry are the ones that protect building occupants. Previously, in the March/ April 2013 Issue, we went behind the scenes to show how thermal and ignition barriers are tested. Now, we make the transition from controlled testing to real world usage.
Cause and Effect
Spray foam is a potentially combustible material; the same
can be said for most organic materials. While foams are
widely formulated with fire-retardants, exposed spray foam
that comes in contact with flames can still result in a flash
fire. The burn is usually brief and forms a layer of surface char,
as well as producing combustible gases and smoke. Although
the char will offer some degree of protection for unburned
spray foam to prevent it from further contributing to a fire,
there are circumstances in which combustible gases build
up–typically, interior settings. In such situations, temperatures
can rise high enough for the fire to flashover, which occurs
when temperatures reach roughly 700º F. At that point, spray
foam directly contributes to the fire and feeds its growth. It
should be noted that such fires occur in conjunction with
other flammable materials, and also that the concentration
SPRAYFOAM insulation & roofing MAGAZINE 35
