Huge news for the industry! A revised standard from ASTM International published last week reduces the mandatory wait period for obtaining official results from an RH moisture test performed in concrete slabs from 72 hours to just 24 hours.

The change in the standard is due to the fact that results taken at 24 hours and 72 hours are essentially identical.

This will make it much easier, not to mention faster, to perform accurate moisture measurements while installing a wood floor over concrete.

Below is a press release from Wagner Meters detailing this new standard:

ASTM F2170 Update Allows Official RH Test Results at Just 24 Hours

Response to new science proving results taken at 24 and 72 hours are essentially identical

Rogue River, OR (February 15, 2018) –  The international standards organization, ASTM International, published today its revised ASTM F2170 (Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes). The updated standard reduces, from 72 hours to a scant 24 hours, the mandatory wait period before obtaining official, documentable results from an in situ relative humidity (RH) moisture test performed in concrete floor slabs.

This significant reduction in wait time allows contractors and flooring installers to take action on RH test results a full two days earlier than the ASTM F2170 standard previously allowed. It also should enable contractors and flooring professionals to accelerate their construction and remodeling projects accordingly.

ASTM International updated the industry standard for measuring the moisture condition of concrete slabs in response to an ASTM-commissioned Precision and Bias (P&B) interlaboratory study conducted in 2014. That study documented the temperature and RH readings of in situ RH probes at various times within the old 72-hour window, including at the 24-hour mark. The study’s findings confirmed that the readings obtained at 24 hours were statistically equivalent to readings taken at 72 hours.

“Everyone at Wagner Meters is excited about the change to 24 hours, but we weren’t that surprised,” said Jason Spangler, Flooring Division manager at Wagner Meters. “Our own internal testing with the Rapid RH^® system has long shown essentially identical results between the 72-hour and earlier readings.”

“What’s a game changer for flooring professionals is that with the revised F2170 standard, they can now take action after just one day instead of having to wait three days,” emphasized Spangler. “No other industry-accepted test method for concrete moisture offers such fast results, and certainly none are more reliable or accurate than the RH test.”

The F2170 Update Further Supports RH Testing as the Preferred Concrete Moisture Test

ASTM first published its F2170 standard in 2002, in response to Scandinavian research that detailed many of the significant advantages of using RH testing to prevent moisture-related flooring failures. The P&B study results lends further credence to the scientific superiority of RH testing over surface-based moisture condition test methods.

Now, the RH test is shown to be not only more scientifically accurate and reliable, but also more actionable, providing contractors with usable results in a fraction of the time of other test methods.

ASTM International is an international standards organization that has developed and published over 12,000 standards covering a wide range of materials, products, systems, and services.