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This is excellent advice especially on pricing. I wasted 2 years undercutting everyone and wondering why I was always broke. My accountant finally showed me I was making about $8 per hour after expenses. Now I target $85-95 per board foot installed for closed cell residential and I book 6-8 weeks out. The customers who push back hardest on price are usually the ones who will also push back on every other thing. Let them go to the cheap guy.
We switched to HFO (Lapolla 4G) about 8 months ago. Honest review: yield is about 5-8 percent lower per set, handles slightly differently in cold, but cell structure is actually better – finer and more uniform. On the business side we have gotten 3 commercial jobs specifically because we marketed it as low-GWP foam. ESG-focused clients pay the premium. It is not a massive game changer but it is a real differentiator in the right markets.
Indiana CZ5 contractor here. Yes, 2 inch closed cell on rim joists is a Class II vapor retarder – you do not need poly there. My process: spray the sill plate and 6 inches of foundation wall first, then move up to the full rim joist. This creates a continuous air seal. Then lap the ground poly barrier up the foundation wall 6-8 inches and tape it. Perfect thermal and vapor bridge with no gaps. I have done it this way for 5 years with zero issues.
Great thread. One more I use: the icepick test. Spray a golf-ball size bead and wait exactly 30 seconds. Poke it with an icepick or thin screwdriver. If it goes in smooth and the foam springs back = good ratio. If it tears instead of compresses = resin rich. If it goes in like butter with no resistance = ISO issue or heat problem. Takes 2 minutes and tells you everything before you commit to a full pass. I do this at the start of every job and after any drum change.
CZ4A metal roofs – I use a rule of thumb of R-15 minimum (about 2.5 inch closed cell) for walls and R-25 (about 4 inch) for the roof deck. At 4 inch closed cell, the dew point stays outside the foam layer in CZ4A even on worst-case winter nights. For adhesion on galvanized metal: no primer needed if the metal is clean and dry. On painted metal it depends – fresh acrylic paint is usually fine. Old chalky paint needs light sanding first. Always do a pull test before committing to the full roof.
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Treated lumber and OSB is a known adhesion issue with closed cell. ACQ and CA copper-based treatments can inhibit adhesion significantly. Lapolla tech bulletin actually warns about this. Your fix: prime with a water-based primer before foam application on any treated material. For OSB specifically, I now always ask the GC if it is treated before quoting. If it is, I add 15 percent for primer cost and time.