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

  • sapling sprouting from a cracked stone

    Lessons in Resilience: Disaster Recovery in Our Schools

    Facility managers play a pivotal role in how well a school weathers and recovers from a crisis. Whether it's a hurricane, a flood, a tornado, or a man-made event, preparation determines resilience.

  • Photo credit - Chuck Coates

    Florida District Modernizes Central Energy Plants at Two High Schools

    Flagler Schools, a public school district in Flagler County, Fla., recently partnered with Matern Professional Engineering to modernize the central energy plants at two of its high schools, according to a news release. The project is part of a larger, district-wide effort to reduce energy costs and operational expenses.

  • Image courtesy of Kahler Slater

    UW–Madison Announces Completion of Morgridge Hall

    The University of Wisconsin–Madison recently announced that construction is complete on Morgridge Hall, a new academic building, according to a news release. The facility opened September 3 at the start of the fall semester, consolidating the School of Computer, Data & Information Sciences into a single facility for the first time.

  • Spaces4Learning Trends & Predictions for Educational Facilities in 2026: Part I

    We asked, you answered, and the results are in! Last year, we put out a call for submissions to collect our readership’s opinion on trends and predictions for K–12 and higher education facilities in 2026.