Lift slab construction is a method of constructing concrete buildings by casting the floor or roof slab on top of the previous slab and then raising (jacking) the slab up with hydraulic jacks, so being cheaper and faster as not requiring boxing and supports for casting in situ.
The Johnstone Hall a dormitory at Clemson University, Clemson, South Carolina was erected using this method in 1954. Several of the blocks have now been demolished, and campus legend says that that two other similar structures built elsewhere collapsed before completion.
The method was involved in the L'Ambiance Plaza collapse in Bridgeport, Connecticut during construction in 1987, and resulted in a major nationwide federal investigation into this construction technique in the United States, and a temporary moratorium of its use in Connecticut.[1]
A patent was issued to Tom Slick for this construction method, called the "Youtz-Slick" method, in 1955.