Effective October 1, 2011, the Maple Flooring Manufacturers Association (MFMA) will ONLY recognize relative humidity (RH) testing as the standard method for reading concrete moisture levels with a concrete slab.
The MFMA recommends that the RH level for a concrete slab for a non glue-down maple floor system is 80% or lower and for glue down systems the RH should be 75% or lower before installation commences.
The ASTM method is F2170 “Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using In-Situ Probes”.
For more information, please visit the MFMA & WOOD page on my site, or visit www.maplefloor.org
The miscellaneous ramblings of Eric D. Lussier, CSI, CDT