Slab considerations: weight loading - 3-4 lighties? What do you call a lightie? Under 5700kg will give you a max single axle wheel loading of 57kN, requiring slab thickness of 88mm mesh reinforced, but it depends on the base soil-is it stabilised, drained, the surface size, expansion joints, concrete type etc. The footings are a different story altogether. If you don't know what you are doing and don't want the slab to crack or the shed to collapse on your aircraft, get a builder.
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