Associations Adopt Statement on Floor Flatness

St. Louis, MO, May 18, 2012 -- The American Society of Concrete Contractors said that the National Tile Contractors Association has endorsed a position statement on floor flatness tolerances written and published by the ASCC.

The associations said they will use the document to help resolve the incompatibility of tolerance-measuring methods between the flooring and concrete construction industries.

The statement, Division 3 versus Division 9 Floor Flatness Tolerances, is also endorsed by The National Wood Flooring Association and The Flooring Contractors Association.

The statement explains that flooring contractors (Division 9) and concrete contractors (Division 3) measure floor flatness by different means.

In addition, floor flatness changes with time, due to a process called curling. Curling makes it impossible to predict what the flatness of a slab will be when the floor coverings are installed.

The solution to this, the associations say, is for the owner to provide a bid allowance, established by the designer and based on the floor covering requirements, for grinding and patching necessary to close the gap between Division 3 tolerances and Division 9 tolerances.

The difference between how Division 3 and Division 9 measure floor flatness, and the changes that occur in a concrete slab between pouring and the time the floor covering is applied, have been the source of many arguments, much misspent time and numerous lawsuits, says Clay Fischer, president of ASCC.