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

  • Massachusetts K–12 District Selects Architect for New Junior High

    Swansea Public Schools in Swansea, Mass., recently announced that it has selected Finegold Alexander Architects to design a new junior high school for the district, according to a news release. The firm will create the Feasibility Study and Schematic Design for Joseph Case Junior High School after a lengthy selection process by the Massachusetts School Building Authority (MSBA).

  • Round Rock ISD Completes New Early College High School

    Round Rock ISD near Austin, Texas, recently announced that construction is complete on a new, 46,500-square-foot campus for Early College High School, according to a news release. The new facility will allow the school’s students and staff to move from portables into a permanent building and increase its enrollment to 500.

  • Zurn Elkay Releases 2025 Sustainability Report

    Zurn Elkay Water Solutions recently announced the release of its annual sustainability report, according to a news release. The 2025 report discusses the organization’s efforts to maintain good environmental stewardship and the solutions provided in helping customers meet sustainability goals.

  • 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.