Rediculious R value claims

[JSK76]

I've looked at a bunch of manufactured fish houses in the last few months and I've seen at least two manufactures one claiming a R-38 and one was R-24. High density spray foam has an R value of 6 per inch so even if they used a full 2x4 at 3.5" deep you would only get r-21. I don't think anyone is using a full 3.5 wide wall either so a 2x3 (2.5" actual) is no more then r-15. What are these guys doing to come up with such a high number? Adding the 4 walls and roof together?

[PurpleFloyd]

From what I know you would need about a 9 inch wall to get that rating.

[ncesi]

The foam we see on the jobs has a R value of 8.5 per inch and this is the closed cell polly something. There is a more open cell softer foam we also see that has a lower R value but I do not know what I is for sure. At least that is what our foam guy tells us.

[Bureaucrat]

Here's an education on R-value and why the type of insulation you use and how well it's installed is more important than the actual R-value.

It's long, so set aside a few minutes:

http://www.sprayfoams.info/foam/the-r-value-myth/

After reading that, closed cell spray foam should be standard in a fish house. The science makes sense.