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

  • Higher Ed is Betting on New Buildings While Quietly Undermining Their Campuses — Here’s Why

    In this climate, the owner’s representative has changed from a delivery-focused advisor to a strategic campus partner. Institutions are increasingly relying on owner’s reps not just to manage, cope, schedule, and budget, but also help evaluate whether a project should proceed at all.

  • Porter Family Center

    Porter Family Center for Innovation and Academics

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

  • Cal Poly Humboldt Starts Construction on Healthcare Education Hub

    California State Polytechnic University, Humboldt in Arcata, Calif., recently announced that work has begun on a renovation project that will turn the Stewart Building into a new Healthcare Education Hub, according to a news release. The university is partnering with Sundt Construction Inc. for construction services.

  • Academy of Classical Education Breaks Ground in Louisiana

    Charter Schools USA (CSUSA) recently announced the groundbreaking of a new public charter school in Covington, La., according to a news release. The Academy of Classical Education at Covington will enroll students in grades K–8 and is scheduled for completion in August 2026, just in time for the new school year.