Store › residential concrete -- Major Image 1 of 1 residential concrete -- Major $3,000.00 Concrete Slab for Shed Foundation, estimated between $3,000 to $8,000 for a slab measuring 10'x10' to 20'x20'. Add To Cart Added! Concrete Slab for Shed Foundation, estimated between $3,000 to $8,000 for a slab measuring 10'x10' to 20'x20'.