Skip to main content
Add as a preferred source on Google

Concrete Slab Configuration Raises Concerns Among Sports Flooring Installers

  • 01/23/18

OAKBROOK TERRACE, IL – Concrete slab configuration is very important in the success of a new maple floor installation.  Placing a below-slab vapor barrier directly beneath the concrete slab is proper and typical.  Placing any type of fill material between the below-slab vapor barrier and the concrete slab frequently causes moisture-related problems with the finished maple surface.

The Maple Flooring Manufacturers Association (MFMA) requires the general contractor to provide a concrete slab troweled smooth and flat to a tolerance of 1/8 of an inch in a 10-foot radius, subject to the approval of the MFMA wood flooring contractor. By placing sand between the vapor barrier and the slab, a flatter concrete slab with less initial curling can be produced.  However, this configuration allows the sand to act like a sponge—trapping moisture within the sand layer during the concrete pour. Over time, trapped moisture can migrate up through the concrete slab and cause moisture-related difficulties with subfloor components and the finished wood flooring surface.

The only MFMA-recognized method for reading concrete moisture levels within a slab is by testing its relative humidity. Please refer to the instructions of the manufacturer’s relative humidity test kit for complete details on how to administer the test correctly. MFMA recommends the relative humidity level for a concrete slab for a non-glue-down maple floor system be 85 percent or lower and for glue down systems the concrete slab relative humidity level should be 75 percent or lower before installation.For concrete relative humidity conditions above MFMA’s recommendation consult your MFMA Sport Floor Contractor or your MFMA Manufacturer.

For more information regarding variations to MFMA’s recommended concrete slab configuration, please contact MFMA’s technical director at 888/480-9138 or email [email protected].

Featured

  • UNT Dallas Holds Ribbon-Cutting Ceremony for $100M STEM Building

    The University of North Texas at Dallas in Dallas, Texas, recently celebrated the opening of its new, $100-million STEM Building, according to local news. The ceremony on Dec. 2 preceded the first day of classes in the facility on Jan. 12, 2026.

  • Geometric abstract school illustration

    How Design Shapes Learning and Success

    Can the color of a wall, the curve of a chair, or the hum of fluorescent lights really affect how a student learns? More schools are beginning to think so.

  • Kimball International Releases Curated Design Support Program

    Commercial furnishings company Kimball International recently announced the launch of a new end-to-end design support program, DesignSuite. According to a news release, its goal is to guide architecture & design professionals and dealer partners through the process from vision to specification.

  • University of Arizona Approves New Residence Hall

    The Arizona Board of Regents recently approved plans for a new residence hall at the University of Arizona in Tucson, Ariz., according to a news release. The new facility is scheduled to open in fall 2028 and have the capacity for more than 1,200 students, enforcing a new university expectation that all first-year students live on campus.