After extensive water damage, both the floor, chipboard, and polystyrene were affected in parts of the basement level. There was 3cm of water on top of the concrete slab! Now everything has been torn out and partially dried. The drainage is from 2007, and after a mechanical dehumidifier has been running for almost 3 months, the outer walls have dried properly, but the concrete slab is still wet (RH higher than 85%). Before the demolition, there was underfloor heating, and the walls had wooden studs with double layers of drywall. That wasn't good since it has molded quite a lot given that it is and will remain such a humid environment. Now the insurance company has sent moisture technicians who argue that there is no point in trying to dry the concrete slab, and that it is enough for the outer walls to dry properly to restore. The insurance company wants me to pay for a Nivellsystem, i.e., studs with screw-adjusted plastic feet that are screwed into the concrete so that no organic material is against the concrete slab. Then insulation is hung between the studs, and a chipboard floor is laid on top of the studs. What I am worried about is that the concrete slab has probably become wet evenly across the entire basement level, including areas that the insurance didn't tear up. There's a risk it will become moisture-damaged over time if it's not properly dried out, right? Is there anything else I should do? I would like to have the thermal insulation back on the outer walls, but is it too risky given that the concrete slab remains wet? Is there anything I can do to keep the walls and slab dry in the long run?
