An off-ratio foam is caused by a deficiency of one of the component chemicals (A- or B-side) during application. The reaction of an off-ratio foam is readily visible to the trained SPF applicator. Off-ratio foam will negatively affect SPF yield, performance, and worker safety.

SPFA believes that the path to a healthful, safe, high-quality and performing SPF installation travels through the hands of a knowledgeable, trained, experienced, and ideally PCP-certified professional contractor.