Using ASTM E1155 to Determine Finished Floor Quality: Background and Areas for Consideration

A commonly used standard to quantify finished quality of elevated and slabon- ground slabs is the ASTM Standard E1155. The procedure outlines the method of profiling concrete to determine the flatness (FF) and levelness (FL) of the concrete finish. This method is generally considered an improvement over the "straight-edge" method and has been adopted by the American Concrete Institute as the default method to determine concrete finish quality. Although the standard has been used successfully for many years by owners, general contractors, and concrete subcontractors, problems can arise if the standard is interpreted incorrectly. Data gathered from this standard is often used, or misused, to evaluate issues unrelated to finishing, such as lack of camber of steel beams, or deflection of elevated floors after concrete is placed. To further complicate issues, the technical basis for the method is not referenced in the standard and is very difficult to find, which can leave flatness and levelness readings open to various (mis-) interpretations. This paper begins with a presentation of the fundamental concepts of the FF and FL system. Also, with the help of case-studies and analytical simulation, this paper demonstrates that the length of a sampled profile has an effect on the FF and FL numbers. In addition, this paper demonstrates the problems associated with using widely spaced topographic survey points to determine the flatness and levelness of completed floor slabs, a common mistake used to determine floor surface quality "after-the-fact".