Hi All,

Looking at buying a house, slab on grade, in climate zone 7. We asked for the building plans. The house was completed in 2019, pre-2020 revision to our state building code.

I am new to slab on grade, but I believe this is monolithic. It’s not up to current post-2020 code, I think, because the horizontal insulation only extends 3′. The depth of the rigid vertical insulation around the perimeter is 1’8″. However, it does have a half-inch greater slab thickness than current code and has greater compression strength (4000).

Wife has severe mold allergies so I’m trying to figure out what we could expect in terms of longevity and safety for her. Can you give me insight about how well this slab might function even if not quite up to current code?

Thanks,
Ken