The May 2010 fire that destroyed this net-zero home in Hudson, Quebec, is thought to have started in a too-thick layer of freshly applied spray polyurethane foam
Massachusetts Fire Officials Urge Caution With Spray FoamIt's well-known that two-component spray polyurethane foam (SPF) gives off a substantial amount of heat as it cures. That heat - the result of an exothermic chemical reaction - ordinarily dissipates quickly. But if too thick a layer of foam is laid down at once, the internal heat can accumulate, leading in extreme cases to temperatures high enough to cause a fire. While such events are thought to be rare, concerns in Massachusetts about several recent structure fires involving spray foam has brought the issue into the spotlight.Three fires and a death. On...