The author, a concrete consultant, believes that floor contractors can help reduce callbacks and potential litigation by furnishing building owners with comprehensive manuals that detail the expected behavior of concrete floors and offer advice for floor inspection, maintenance and repair. He details some of the items that could be included in such an owner's manual, grouping them under the following topics:
ACI 117, Standard Tolerances for Concrete Construction and Materials, gives tolerances for slabs up to 12 inches thick of +3/8 inch and -1/4 inch. For the past few years, I've been gathering data on thicknesses of concrete slabs, and I've found that most slabs don't conform to ACI 117.
Most specifications for surface tolerances are ambiguous and perhaps this is why there is no consensus on how to measure for compliance with tolerances.
The previous article explained the basics of concrete as they relate to concrete floors on grade.
During the design stage of most buildings, little if any attention is given to floors on grade.
