Closed cell foam delaminating from OSB sheathing – help!
Having a nightmare job here. Installed 2 inch closed cell on the interior of OSB wall sheathing about 3 weeks ago. Customer called saying the foam is peeling away from the OSB in some spots.
Details:
– Product: Lapolla 4G HFO
– Temps during install: 55F substrate, 60F ambient
– Substrate was dry (moisture meter under 12%)
– No primer used
– Yield looked normal, cells looked good
The OSB was treated/pressure treated – could that be the issue? Lapolla tech line thinks it might be the preservative treatment reacting with the foam. Anyone dealt with delamination on treated OSB before?
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.