The method proposed here for specifying and measuring floor tolerances uses elevation readings and slope measurements on the as-built floor. The method includes a statistical specification that uses readily understood standard engineering and statistical terms. It is easy and inexpensive to use and is suitable for slabs on ground, elevated slabs, and floors with ramps and pitches. RELATING AS-BUILT FLOOR MEASUREMENTS TO A REFERENCE SURFACE Compliance with specifications is checked by comparing the as-built floor surface with the specified surface. To compare specified and as-built surfaces, the following characteristics of the as-built floor must first be determined: overall elevation, overall slope, elevation variability, and local slope. A single set of elevation measurements is used to calculate overall elevation, overall slope, and elevation variability. Separate measurements are used to evaluate local slope. A table is provided which shows proposed tolerances for six floor-use classifications (three classes of floors for either vehicular or nonvehicular use).