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

  • William Penn Charter School

    Richard A. Balderston OPC’69 Lower School

    Established in 1999, the Education Design Showcase is a vehicle for showing off innovative — yet practical — solutions in planning, design, architecture, and construction. The Richard A. Balderston OPC’69 Lower School has been recognized with an EDS 2026 Grand Prize award in the category of New Construction.

  • Back-to-School Playground Safety: 7 Common Hazards to Look for After Summer Break

    As summer break comes to an end, school administrators have plenty to prepare before students return. While classrooms, hallways and common areas often receive attention during all the back-to-school preparations, the playground should not be overlooked. Months of weather exposure, storms, and regular wear can leave behind hazards that may not be immediately noticeable.

  • Big Horn Academy

    Big Horn Academy

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

  • Texas A&M Opens First Building at Fort Worth Campus, Breaks Ground on Research Facility

    The Texas A&M University System marked a major milestone in the development of its Fort Worth campus by opening its first completed academic building and breaking ground on a second facility designed to expand research and industry collaboration.