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

  • Sam Houston State University Completes Athletic Stadium Renovations

    Sam Houston State University in Huntsville, Texas, recently announced the reopening of Elliott T. Bowers Stadium after an extensive renovation project, according to a news release. The university partnered with Stantec and DLR Group for the project’s design.

  • Health & Science Building

    Health & Science Building

    Established in 1999, the Education Design Showcase is a vehicle for showing off innovative — yet practical — solutions in planning, design, architecture, and construction. The College of Western Idaho's Health & Science Building has been recognized with an EDS 2026 Project of Distinction award in the category of New Construction.

  • Planning with Clarity: Using AI to Make Better Campus Decisions, Not Just Better Designs

    Higher education leaders are being asked to make increasingly high-stakes decisions about campus facilities amid greater uncertainty than ever before. Social and economic pressures, shifting enrollment, and evolving learning models compete with growing deferred maintenance needs to strain even the most robust infrastructure budgets.

  • Can AI Help Build Stronger Communities in Student Housing?

    Student housing success is shifting from operational performance to student experience, with belonging now at the center. A recent 2025 report underscores a growing emphasis on student well-being, community, and engagement, signaling that expectations now extend beyond logistics to ensure students feel supported in their living environments. AI is enabling that shift by reducing administrative workload and giving teams more time to focus on meaningful student engagement.