Pass lines are created when the end of a pass of foam or coating ties into an adjacent pass.The overlapping of the polyurethane foam or coating can be seen typically as a darker color than the middle of the pass Foam at the pass lines typically contain thinner lifts than the middle of the foam pass as the applicator tapers the foam to uniformly tie the foam passes together.

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.