99% RH in concrete slab

[eaadams]

40K feet, this is a warehouse? What was the place used for in the past? I've seen old warehouses in silicone valley that had trenches cut out to add conduit and never had the vapor barrier replaced. Also are there drains? I've seen places where trucks were being washed inside (like on a pier in San Francisco) and that was re-wetting the slab.