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

  • Designing for Every Mind

    Learning environments have the power to shape not just what students know, but who they become. When a school is designed with genuine empathy—for the full range of ways students think, sense, and engage with the world—it becomes more than a building. It becomes a catalyst for growth, confidence, and belonging. That is the animating idea behind neurodiverse design, and it is one that is transforming how more architects and designers are thinking about school design.

  • Nashville Elementary School Receives LEED Gold Certification

    Goodlettsville Elementary School, part of Metro Nashville Public Schools in Nashville, Tenn., recently achieved LEED Gold Certification from the U.S. Green Building Council (USGBC), according to a news release. The 81,750-square-foot school opened in 2023 and was designed by Goodwyn Mills Cawood (GMC).

  • Big Horn Academy

    Big Horn Academy

    Established in 1999, the Education Design Showcase is a vehicle for showing off innovative — yet practical — solutions in planning, design, architecture, and construction. Big Horn Academy has been recognized with an EDS 2026 Project of Distinction award in the category of New Construction.

  • California High School Opens New Classroom Building for 7th-, 8th-Graders

    Santa Rosa City Schools in Santa Rosa, Calif., recently announced the completion of a new classroom building for Piner High School. As the campus transitions to a Junior/Senior High School, the facility will play home to the school’s new population of seventh- and eighth-grade students.