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Spray foam for top of foundation wall – any compelling reason for two-component vs one-component?

jadziedzic | Posted in Energy Efficiency and Durability on

I need to cover the exposed top edge of the concrete foundation walls with an air barrier / insulation (~R5) that can easily tie into the closed-cell spray foam that was applied to the rim board during construction; due to the varying surface of the existing foam, spray foam seems to be the easiest approach.  (Yes, the foam installer should have fully lapped the foam onto the top of the concrete, but they didn’t.)

Vega Bond (and a few others) sell one-component canned foam that is “mostly” closed-cell which can be applied using their gun with a spray tip that creates a fan pattern.  It seems this would be a lot easier than dealing with the uncertainty of two-component proper mixture in an area that is less than accessible should the worst case of bad foam occur.  Since these one-component cans typically cover around 20 board feet it would be a lot easier to deal with those than big tanks and hoses.   (I also wasn’t impressed with the application and pattern results from a small Froth-Pak kit I used and suspect I’d have similar issues with a larger (200 board foot) kit.)

Is there anything intrinsically “bad” with the one-component spray foam products like Vega Bond’s “Purple Coat” as compared to the DIY two-component kits for this specific application?    Any suggestions and/or tips would be appreciated.

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