Two national flooring associations have endorsed a position statement on floor flatness tolerances written by the American Society of Concrete Contractors (ASCC). Members of the National Wood Flooring Association and the Flooring Contractors Association will use the document to help resolve this issue.

The statement explains that flooring contractors (Division 9) and concrete contractors (Division 3) measure floor flatness differently. Also, floor flatness changes with time due to curling. This makes it impossible to predict what the flatness of a slab will be when floor coverings are installed. The associations agree the solution is for the owner to provide a bid allowance, established by the designer and based on the fl oor covering requirements, for any grinding and patching necessary to close the gap between Division 3 and Division 9 tolerances.

View the position statment.

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