How Do I Insulate My Bathroom Floor?
Your plan is what most people &amp; contractors do. But, latest basement testing has revealed that even with foam board or spray-in foam you need 6-mil poly against the concrete &amp; then also on top of it. Under-it stops moisture &amp; air from wanting to come in &amp; On-it stops moisture &amp; air from wanting to penetrate it. Here's a really good video breakdown I recently ran across of what's been determined.