Concrete might look dry on the surface — but what’s happening inside the slab can determine whether your coating succeeds or fails.
Moisture-related failures are one of the most common causes of peeling, blistering, and delamination in epoxy and resinous flooring systems. The culprit? Excess moisture vapor trapped beneath the coating.
Skipping moisture testing can turn a profitable job into an expensive redo.
Concrete is porous and continues to transmit moisture vapor long after it cures. When coatings are applied over slabs with high internal moisture:
The result: costly removal, re-prep, new materials, and lost time.
Measures internal slab moisture (ASTM F2170).
Often preferred by manufacturers because it reflects long-term moisture conditions.
Measures surface vapor emission rate (ASTM F1869).
Useful, but only evaluates the top portion of the slab.
Great for quick scanning and identifying trouble areas — but not a replacement for ASTM-compliant testing.
Even older concrete can retain and transmit moisture.
Most coating manufacturers specify maximum RH or MVER limits. Exceeding those limits can void warranties and lead to failure.
Testing takes a few extra hours. Replacing a failed floor takes days — and thousands of dollars.
Moisture testing isn’t optional — it’s part of professional surface prep.
Know your numbers before you coat. It protects your profit, your reputation, and your customer!
Have a blog topic you want us to discuss? Leave a comment below!