August 2024 - Why Spray Foam Fails and What to Use Instead

Jeff Flaherty brings in Corey Murphy, product consultant for 475 High Performance Building Supply and passive house instructor at RIT, to talk about why spray foam is not the long-term solution most contractors sell it as. Corey walks through why a thin layer of closed cell foam traps moisture in organic materials like OSB and plywood with nowhere to go, why foam separates from rafters within a heating season, and why the wall has to be able to dry in both directions to last. Jeff and Corey also dig into why the blower door test is the single best tool any contractor can use, why code at three air changes per hour still means you're replacing all your conditioned air three times an hour, and why making a house airtight without foam is not only possible but more durable long term. Plus a home show story about a famous house flipper who told a room full of contractors to get a blower door test done, while Jeff was the only contractor at the show who had one.