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

  • Texas K–12 District to Build New Elementary, High Schools

    The High Island Independent School District on the Bolivar Peninsula in Southeast Texas recently announced that construction on a new elementary school and a new high school will begin in January 2026, according to local news. Funding will come from a $27.9-million bond passed in May 2025.

  • Tennessee State University Gains Approval for New Engineering Facility

    Tennessee State University in Nashville, Tenn., recently announced that it has received approval from the Tennessee State Building Commission to build a new engineering building on campus, according to a university news release. The 70,000-square-foot, $50-million facility will play home to the university’s engineering programs and the Applied & Industrial Technology program.

  • FAU Starts Construction on Holocaust and Jewish Studies Building

    Florida Atlantic University recently began construction on a new academic building for its campus in Boca Raton, Fla., according to university news. The Kurt and Marilyn Wallach Holocaust and Jewish Studies Building will stand two stories, measure in at 22,000 square feet, and play home to the university’s Holocaust education and Jewish studies programs.

  • UCNJ Launches $30M Modernization of Physical Education Center

    The Union College of Union County (UCNJ) in Cranford, N.J., recently broke ground on a new $30-million modernization project for its Physical Education Center (PECK), according to a news release. The college partnered with DIGroup Architecture for the project’s design, transitioning the existing 42,000-square-foot structure into a campus hub for student athletics and campus life.

Digital Edition