Rigid insulation over a concrete slab
Fairholme
| Posted in Energy, Heating & Insulation on
We’re doing a kitchen addition and due to the small space have decided to forgo a crawl space access and use a slab on grade. I’m thinking the top of slab will be 4.25″ below existing top of subfloor, we will install treated 2×4 sleepers and 3.25″, R21 foil faced rigid insulation between the sleepers covered by a new subfloor. The finished floor will be tile over hardibacker. What are the moisture implications of this assembly?
Replies
super seal the CC 1st...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Fairholme,
Instead of interrupting your foam insulation with a bunch of parallel sleepers, why not install constinuous XPS foam insulation underneath the slab? Make it as thick as you want (or can afford). And don't forget additional vertical foam at the perimeter.