Cement board “slab” on grade
Hello GBA folks,
I’m in the process of designing a house in zone 7/8 and would like your feedback on this design idea.
Instead of a concrete slab on grade, glue 2 layers of cement board, such as 1/4″ Hardie board to each other and to 3 or 4 inches of EPS foam. Offset each layer to avoid matching seams. Prepare the bed with crusher fines and perhaps sand to get level and compacted surface for the foam. This might be difficult? Add a vapor barrier below the foam. Finish floor with tile, carpet (glue tack strips to cement board), etc, but I’d like to use cork.
Benefits are cost, doable by homeowner, easier to fix if needed. no wood in floor in case of water spills, and can build in a chase for utilities to make repair easier.
Resell/banker issues is a concern. It would be a cement floor though. Maybe that would help?
Seems like this would be structurally sound for pianos and other stuff, but probably not non-load bearing walls. Is there a better material than cement board or add more layers?
Sorry if this has been discussed before. My googling found nothing. What do you think?
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