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

  • Preparing for the Next Era of Healthcare Education, Innovation

    Across the country, public universities and community colleges are accelerating investments in healthcare education facilities as part of a broader strategy to address workforce shortages, modernize outdated infrastructure, and expand clinical training capacity. These projects, which are often located at the center of campus health and science districts, are no longer limited to traditional classrooms.

  • North Carolina District Completes New Elementary School

    The Wake County Public School System (WCPSS) in Holly Springs, N.C., recently announced that construction on a new elementary school has finished, according to a news release. Rex Road Elementary School measures in at 133,000 square feet and is the fifteenth school that general contractor Balfour Beatty has completed for the district.

  • 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.

  • California School District Completes Elementary School Modernization

    The San Diego Unified School District in San Diego, Calif., recently held a ribbon-cutting for a whole-site modernization of Pacific Beach Elementary School, according to local news. The school first opened with one building in 1930 and added six more between 1938 and 1957.