Concrete Slab Configuration Raises Concerns Among Sports Flooring Installers

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

  • University of Rochester to Break Ground on New Student Life Center

    The University of Rochester in Rochester, N.Y., recently began construction on a new Student Life building, according to a news release. The first floor will contain campus-wide gathering, program, and rehearsal space; the second floor will play home to the Greenbaum Center for Jewish Life.

  • California District Debuts New High-School CTE Center

    The West Sonoma County Union High School District (WSCUHSD) in Sebastopol, Calif., recently held a ribbon-cutting ceremony for the new CTE Center at Analy High School, according to a news release. The district partnered with Quattrocchi Kwok Architects (QKA) for the facility’s design and GCCI for its construction, and funding came from local Measure A bond funds.

  • Houston-Area High School Receives Best Project Award from ENR

    Tomball West High School near Houston, Texas, recently received a K–12 Education Best Project Award in Engineering News-Record’s 2026 Texas & Southeast Best Projects Awards, according to a press release. The new facility was completed in May and opened its doors to students for the fall 2026 semester.

  • Growing Allied Health Workforce Demands Fueling Greater Need for Higher Education Facilities

    With the demand for healthcare professionals at an all-time high, colleges and universities are challenged with supporting the workforce demands in their own communities. Careers in allied health generally require specific training and/or certification, with some positions requiring degrees, certified credentials, and continuing education.