Floor insulation, cellulose vs hard foam
The house I'm building is 24' x 48' on a crawl space with a trussed roof.
The floor has 2x8's for floor joists on 19.2" centers. The sub floor is 3/4" T&G Avantech sub floor panels. On top of the sub floor, I am planning to use solid bamboo snap together wood flooring throughout the entire house.
I originally planned to insulate the floor with cellulose by blowing it in from the crawl space after the sub floor is down, using the glue-on mesh made for that installation method. Then I would sheath the bottom of the joists with preforated pegboard followed by 1/4" hardware cloth for rodent prevention.
Now, I'm wondering if maybe I could just glue hard foam sheets over the sub floor and then the bamboo flooring over the foam.
It seems this would be a lot easier and simpler, but perhaps quite a bit more costly.
Would this be feasible ? And, if so:
What thickness of foam would equal the insulation value of 7.5" of cellulose ?
What kind of foam should I use; any suggested sources ?
And finally, would the foam need to be thick enough to where I would need to use a double bottom plate for the interior walls so that I would have something to nail the bottom of the drywall to ?
Or would it be feasible to just build the interior walls after the bamboo flooring is down (don't know how much that would interfere with the flooring's ability to 'float') ?