Why do a slab over the glider storage at all? Have your slab on grade, then build up CMU stemwalls at 10'o.c., and span over the gliders with composite deck (concrete filled metal deck). You'd have vertical bars in the cmu, and wire reinforcing in the slab, cmu and composite deck. And there's no need for formwork.JT wrote:The answer is that there are actually two slabs in Hiro's design. The first is on-grade and would keep moisture from seeping up from the ground or pooling under the stored gliders. The second slab is elevated about 30 inches by stem walls supported by below-grade footings. The second slab is the walking surface. The glider storage is sandwiched between the two slabs. The footings and stem walls are what require re-bar. The raised slab can be formed by a temporary, shored-up platform with cement poured over re-bar or by pouring on top of steel decking that becomes part of the structure under the concrete. There is no re-bar in the slab-on-grade.
All the forms construction and concrete adds a lot to the cost. I am investigating substituting pre-cast block for the stem walls which would greatly reduce labor and materials expense. However, this requires revising the engineering. Is there a licensed, structural engineer in the club who would donate some calculation time?
Also, the design calls for below-slab waterproofing, right? Other wise you've got water seeping up from the ground into the glider storage area.