Sources: American Society for Concrete Contractors (ASCC), St. Louis; CP staff
The International Union of Bricklayers and Allied Craftworkers, International Masonry Institute, and Tile Contractors Association of America have endorsed the ASCC Position Statement on Floor Flatness Tolerances, joining supporters Flooring Contractors Association and National Wood Flooring Association.
Group members will use the document to help resolve an ongoing construction issue stemming from different floor-flatness measurement methods among concrete (CSI Division 3) and flooring (Division 9) contractors. In addition to variations in measurements, floor flatness changes with time, due to a process called curling, which makes it impossible to predict slab flatness upon floor covering installation. The associations call for owners 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 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,” affirms ASCC Technical Director Bruce Suprenant. “We believe an allowance in the bid would cover the cost of the patching and grinding that is almost always required, [while bringing] the issue to the attention of the owner and designer early on, hopefully forcing them to acknowledge that the point in question does in fact exist.”
“Many members have successfully used this Position Statement to drive home this point with owners,” adds ASCC President Mike Poppoff. “We believe a joint statement from Division 3 and Division 9 contractors will carry even more weight. The intent of all six organizations is that it will be used to make the construction process go more smoothly for all involved.” — www.ascconline.org