Why Relative
Humidity Testing?

For successful flooring projects, it is crucial to measure moisture below the surface of the concrete slab. Other tests like Calcium Chloride are surface-based and do not give reliable results. For example, the anhydrous calcium chloride test measures only the moisture vapor emission rate coming from the slab’s surface. It tells you nothing about the moisture condition deeper in the slab. Only the in situ relative humidity (RH) test is scientifically proven for accuracy and reliability. Our Technician is certified through Wagner to test your slab correctly per ASTM F 2170

But which moisture test should you use? Several different methods of moisture testing are available. How can you be sure that you’re choosing a reliable method of moisture measurement?

Is one test method any better than another?

The simple answer is yes! The scientific evidence consistently points to a single method of testing as the most accurate and reliable. This is why people in the flooring industry today are moving more and more to the use of in situ relative humidity (RH) testing.

You’ve come to understand the importance of testing the concrete slab’s moisture condition when preparing for a flooring installation. Otherwise, you may end up with warping, buckling, peeling, debonding, mold, or other serious issues.

Testing is really quite easy. Just be sure you test for moisture before you install any finished floor product. This minimizes the risk of a catastrophic flooring failure. Floor coverings, adhesives, and other finished floor products should never be used on a slab that isn’t sufficiently dry.

RH testing, standardized as ASTM F2170, involves placing in situ RH probes at specific depths in the slab. After allowing the RH probes to equilibrate, measurements of RH are taken to assess the overall moisture condition of the slab.

Decades of research in Europe and the United States clearly show that RH testing is the most reliable method for accurately determining the moisture condition of concrete floor slabs.