The February 1989 issue of "Concrete Construction" contained a nomograph for use in estimating the volume of concrete needed for slabs of varying thickness and area. Joseph Deigh, a retired civil engineer, devised the nomograph so contractors could quickly determine concrete volumes on the job without having to use complicated formulas. Now Deigh has a revised version of the nomograph that works for metric and English units of measure. Both units of measure are shown side-by-side on each of the three nomograph scales.
To illustrate how the nomograph works, Deigh provides two examples. The first example shows how to find the volume of concrete needed for a slab based on a slab area measurement of 700 square feet and a thickness of 5.5 inches. The second example shows how to determine slab area based on concrete volume and slab thickness. Deigh said the nomograph is not as precise as mathematical formulas. But it is accurate within a range that is practical to the jobsite. Information on how to receive a free full-page-size copy of the nomograph is included in this article.