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

  • Wold Architects & Engineers Announces Acquisition of JJCA

    Wold Architects & Engineers, based in Minneapolis, Minn., recently announced that it has acquired JJCA, an architecture firm based in Nashville, Tenn., according to a press release. JJCA specializes in healthcare and education design; the partnership allows both firms to expand their presence across the country while building on existing strengths.

  • University of Pennsylvania Releases Design of Future Physical Sciences Building

    The University of Pennsylvania (Penn) in Philadelphia, Penn., recently released renderings of an upcoming 350,000-square-foot Physical Sciences Building, according to news release. The facility was designed by CO Architects and will unite the university’s departments of Physics and Astronomy, Mathematics, and Earth and Environmental Science.

  • University of Pittsburgh to Build New Residence Hall

    The Board of Trustees from the University of Pittsburgh in Pittsburgh, Penn., recently approved the construction of a new residence hall for first-year students, according to university news.

  • GeoCam and UCLA: Modernizing Campus Accessibility Mapping

    In early 2025, UCLA partnered with GeoCam to capture and modernize its pedestrian infrastructure data. The goal was ambitious but clear: to produce a high-accuracy, imagery-backed digital map of every sidewalk, pathway, ramp, and ADA-related feature on UCLA’s 419-acre campus.