Sprayed Rim Joist seal with – Open Cell foam ( Zone 5 )
MaxX2
| Posted in General Questions on
Hello,
I been working on finishing basement, house is 5 years old in Niagara Falls NY
Rim joist was stuffed with Pink Glass Insulation – and covered with Poly.
I removed the fiberglass and sprayed it with Single Can foam ( Demsun P90 ) same product as Sika Boom®-121 Insulation *claims that its good for Rim Joists.
R 5.6 value per inch ( which is oddly high for open cell foam )
No insulation on exterior
How bad did I screw it up ? What are my options ?
I don’t believe that this is typical open cell as its a bit more dense and has higher r value but its for sure not closed either
Thank you
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Replies
The fact that all of the units are metric makes me question why the R-value is listed in R/in. Maybe there was a translation issue.
The density translates to about 1.4 lbs/ft³ which is in between what we usually think of as open cell (0.5-lb) and closed cell (2.0-lb) densities, so maybe the R-value is accurate.
Foam insulation of any density is typically airtight once it's a few inches thick, so it meets code requirements for locations like yours. As long as you don't have something on the exterior limiting drying--such as ice and water shield--you probably won't experience any problems. For an added measure of safety, you could install a vapor-retarding paint or membrane on the interior.
Michael,
In almost every area - building, groceries, maps, etc - Canada has ended up operating in a hybrid system of metric and imperial units. Our codes are metric, but you would be greeted with a blank face if you asked at the lumberyard where the 38 x 235 joists were.
I didn't realize the country of origin was Canada. I deal more often with European products, which can also have a mix of units but more often they are consistent. And sometimes not well translated to IP.