Slab poured July 15, 2021 in Central TX zone 2 on post and tension with 30″ deep of total pour. Total 3700 sq ft Ranch single story- with 3 car work shop garage (1000 sq ft). Barrier was used. Cement was 4000 psi with no additives and wet dried for 7 days. Framed in November and used Tyvek sheeting and windows in place. Shingled roof on Nov 27. Would think the cement floor would be cured by now but some areas of the slab floor have on and off visible wetness through out the house. Roof not leaking. We did 4000 psi with no additives with intention of polish cement floors–have since changed mind and plan on tiling. No landscaping so no added water. The backside does have only 6-8 inches of exposed slab and gutters and spouts have not been placed yet. What can cause the cement slab to have this wetness?
We are very concerned and hesitant on proceeding with any flooring until wetness is resolved. Any thoughts on why this is happening? Thank you for any assistance and information!
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Replies
Are you saying you poured the floors 30" deep? If so, and you've had walls and a roof over it with plastic under, drying would be a very slow process since the moisture has no place to go except the atmosphere. I'd open everything you can put some big fans on it.
Are there pipes buried under/embedded in the slab?
Water runs downhill and moves from wet to dry. It also will condense out of wet air on cold surfaces.
Exposed slab surface outside the house also can be a place water can enter. can you get some flashing to cover it up so that water coming down the siding is diverted?
Sounds like the house is closed in, are you heating it, or providing good ventilation?
Pics would help.
What is the temperature range for the concrete slab's surface? Check from exterior edge moving into the center of the home.
Compare those temperatures to the dew point for the humidity levels you're dealing with.
It may be that atmospheric moisture (humidity) is condensing on the slab.
This assumes that the interior space is not yet a conditioned space.