We've been asked the question, Do we need to use other types of moisture
testing for floors besides relative humidity? Is it a good idea to use
multiple methods to understand the moisture condition of the floor?
In our opinion, relative humidity is the only method that's necessary
because it reveals the true moisture condition within the concrete, which
is what the floor covering will see after it's installed. Other methods,
such as the calcium chloride moisture emission test, we've shown to be
misleading, and therefore, the most reliable test is really sufficient by
itself.
The electronic handheld meters, as we've seen, only indicate a small
portion of the moisture near the surface of the concrete, and, again, don't
give us a true picture of what's happening deeper down.
When we put in situ probes into the concrete slab, we see the true moisture
condition and it's the best predictor of long term performance of the
floor.