10/19/2026
Yup!
A floor can be well insulated and still not feel great to stand on. So how do you get a little more give underfoot when building on a slab-on-grade foundation?
A GBA Forum member in Colorado is considering three options:
👉 Install 2×4 sleepers on the slab at the same height as the mudsill, then add a subfloor and build the walls on top.
👉 Attach floor joists to the mudsill, then install the subfloor and walls.
👉 Insulate over the slab.
He’s also wondering whether to seal the slab beneath the flooring and how best to handle the rim joists. What would you recommend?
Read our expert's opinion: https://www.greenbuildingadvisor.com/article/qa-spotlight-can-you-build-a-comfortable-wood-floor-over-a-slab