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

  • 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.

  • 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.

  • USC Launches Major AI Initiative After $200M Gift

    The University of Southern California in Los Angeles, Calif., recently announced that it has launched a “transformational” new AI initiative thanks to a $200M gift, according to a news release. The project will leverage AI toward breakthroughs and innovations in subjects like the health sciences, business, security, and the arts.

  • 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.