Crawl space insulation questions

Gates

How much insulation is needed to insulate a 168 sq ft crawlspace floor above and what type is necessary for the job!!!

cbaur88

Gates, do a search on youtube "Crawlspace Insulation" and you can find some good information from companies such as Owen Corning, Johns Manville, and some private contractors. I was recently looking into this and I believe they recommended R-19 which you can double check on Owens Corning website.

There is also the question of if it's a vented crawl space or not a vented crawl space. Main difference here I learned is a vented crawl space does not get the walls insulated (although mine are from the previous owner) while non-vented crawl spaces you can insulate the walls with foam boards, batts, etc...If you lay batts between the floor joists, paper side usually goes toward the warm part of the house which would be your floor.

Red Squirrel

There's too many factors that can truely determine this. Idealy the more R value the better, BUT you also want an air seal. Just shoving a bunch of fiber glass is not going to do if it's a damp unconditioned crawlspace.

I'm getting a company to do expanding foam in a small crawlspace I have. It's conditioned space and is entirely concrete, even the ceiling. They'll be putting in 3" R18. Will provide air seal and thermal. Not cheap though.

Earnie

Not just how much but also how it's installed. Here is some informative reading.

http://www.buildingscience.com/docum...archterm=floor insulation


http://www.buildingscience.com/docum...d%20in%20walls


http://www.buildingscience.com/docum...ance-and-codes