One of the difficulties that arises in connection with casting concrete slabs and thin-shell structural elements on the ground is that of providing the special reinforcing steel to withstand stresses that will be present only during the handling operation. Some designers and builders are now doing away with handling reinforcement altogether by performing the lifting operation with rubber vacuum mats. The method has the important advantage of widely distributing the stresses which develop during handling, rather than concentrating them in relatively small areas, as is the case when hooks are cast into the concrete. Reports also indicate that slabs lifted in this manner are much less likely to sustain damage due to whipping.