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

  • Image courtesy of MiEN Company

    6 Ways to Pull Off a Major District Construction Project

    Designing and building a large-scale project on a K–12 campus is a monumental undertaking that requires the right blend of ideas, funding, design and execution to get it right. The process also relies on multiple partners, each of which has to handle its respective aspect of the project while also keeping the district’s broader mission and goals in mind.

  • Greenheck Launches Optics Sensors for Kitchen Hoods

    Greenheck recently announced the launch of factory-installed optics sensors as an enhanced option for its kitchen ventilation hoods, according to a news release.

  • Creating a First and Lasting Impression with Thoughtful, Sustainable Design

    Clemson University’s Nieri Family Alumni and Visitors Center serves as the new front door to campus, anchoring the Tiger experience through each step in the student journey.

  • University of Kentucky Stormwater Harvesting System Receives Award

    The Utilities and Energy Management team from the University of Kentucky recently received a Grand Award at the 2025 Engineering Excellence Awards, according to a university news release. The award from the American Council of Engineering Companies of Kentucky was for the university’s Central Utility Plant (CUP) Stormwater Harvesting System, which activated in fall 2023.

Digital Edition