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

  • Rhode Island Boarding School Completes Student Dorm Renovations

    St. George’s School in Middletown, R.I., recently announced the completion of a $26-million renovation project on Arden-Diman-Eccles Dormitory, according to a news release. The school partnered with Voith & Mactavish Architects (VMA) on the new space, which places a new focus on collaborative community spaces open to both boarding students and day students.

  • Ohio State University Opens 26-Story Hospital

    The Ohio State University Wexner Medical Center recently opened in Columbus, Ohio, standing 26 stories and covering 1.9 million square feet, according to a university news release. The project marks ten years of effort and is the university’s largest single-facility construction project ever.

  • CU-Lock Haven Receives $1.75M Gift for New Entrepreneurship, Media Center

    Commonwealth University-Lock Haven in Lock Haven, Penn., recently received a $1.75-million donation from entrepreneur and alumnus Nicholas Subich ’17, according to a university news release. The funds will go toward establishing the Nicholas Subich Center for Entrepreneurship and Media, a technology-driven hub for innovation and experiential learning.

  • University of Arizona Approves New Residence Hall

    The Arizona Board of Regents recently approved plans for a new residence hall at the University of Arizona in Tucson, Ariz., according to a news release. The new facility is scheduled to open in fall 2028 and have the capacity for more than 1,200 students, enforcing a new university expectation that all first-year students live on campus.