Document the condition
Note where it's showing up on the Charleston property, when it began, any tie to weather or tides, how it's progressed, and prior repair attempts. Photos and rough measurements make the first conversation far more useful.
Read the local context
Measure the moisture coming through the slab before choosing a product, because with the water table this close to the surface the vapor drive is continuous and a coating over an untested slab is the standard way this work fails. Establish the age of the pour, since older slabs frequently went down with no vapor retarder at all. And check the parcel's flood elevation: on a low-lying property the ground level may not be habitable space under the floodplain rules, which changes what the room can be used for and therefore what its floor is worth.
Ask what will be hidden
Moisture testing, contamination, crack and joint condition, surface profile, cure temperature, UV exposure, and traffic all carry extra weight in Charleston, where tidal flooding and salt air work on a slab year-round. Once the coating cures, nobody can check the prep work again, so the written scope needs to spell it out in advance.
Compare complete scopes
A complete Charleston scope addresses protection, access, materials, permitting, testing, cleanup, the restoration itself, exclusions, warranties, and change-order rules.
What official local sources add
Preservation review governs exterior appearance and does not ordinarily reach an interior slab, so for this trade the relevant record is the flood map rather than the district rules. A ground-floor or garage slab on a parcel with mapped flood exposure has a history worth knowing before a coating is specified, because a slab that has taken water before will likely do so again and that predicts the moisture the coating has to survive. In some low-lying properties the ground level is not habitable space at all under the floodplain rules, which changes what the room can be used for and therefore what should be spent on its floor.
Sources were reviewed June 20, 2026. Get the flood zone, historic-district status, and current permit requirements confirmed with Charleston authorities for this exact parcel before signing off on anything.