Son of Ultrathin Slabs Innovative thin slabs get good report cards after one New England winter. by Harris Hyman, P.E. A year and a half ago [NEB, July 1985], I described the installation of ultrathin slabs for use in one- and twostory frame buildings. These are fiberreinforced concrete slabs less than 3 1/2 inches thick, with little or no steel and no thickening at the edges. There are a number of advantages to the ultrathin design: the slabs are easy to form up, and easy to insulate well. There is no need to use steel reinforcing, and less material is used. On paper, ultrathin slabs look like a good idea. Out in the real world, after seeing five
