How to patch a hole in the slab under a kitchen island

moldsmellsubfloor

This is one step further than How do I remove musty smell in coat closet?.

There was a sewage backflow under my kitchen island 🙁 I fixed that problem, but now there's a musty smell in one of the island's drawers.

I removed the built-in stove so I can see the sewage and the subfloor, broke one slab and removed 2 buckets of sand beneath the subfloor around the sewage pipe where the dampness had been. I've now been airing it for a week (I also put a small heater there).

NOW: do I just put new sand, and put the stove back in? Or would you also cover the subfloor hole with a thin layer of cement?

Or is there something else that you would try?

Best Answer

My answer from this question will work for your situation How should I finish around this hole in my slab?

Starting at the lowest level:

  • vapor barrier (6 mil polyethelene plastic)
  • if you have cold winter, you can optioally add an insulation layer: 1" or more of XPS insulation
  • Something to cover the plastic (or insulation). Pea gravel is nice for removability. Concrete will prevent anything from burrowing (in or out)