Key takeaways
- New slabs hold water for weeks or months
- Slabs on grade can release vapor for years
- Tests turn guessing into numbers
- A moisture barrier primer gives coatings a better chance
Why moisture matters
Concrete is made with water, and some stays in the slab long after it hardens. Slabs on the ground also draw moisture up from the soil. A coating can trap that moisture and bubble or peel.
Basements, garages on a slope and ground-level slabs are the most likely to have issues.
How it is tested
A taped plastic sheet is a quick hint: if condensation forms underneath after a day, the slab is releasing moisture. For numbers, calcium chloride kits and in-slab humidity probes measure it against the coating maker's limit.
Test results depend on weather, ventilation and slab age, so we read them on schedule.
What to do about high readings
Options include waiting, improving airflow, fixing the cause or using a moisture-mitigating primer. Standing water or leaks need repair first.
We explain the results and the options, then recommend a plan.
Related services
Quick answers
How long should new concrete cure before coating?
It varies with the slab and coating. Many systems want weeks of curing and a moisture test. We check and tell you the earliest safe date.
Can I use a sealer instead of a barrier primer?
Not for high vapor. Thin sealers do not stop strong moisture movement, which is why barrier primers exist.
Ready to talk it through? Get a free estimate or call 615-431-3789.