24,000/sf of Reinforced Concrete Foundations and Slab Was Completed For Mitch Cox Development. Call Volunteer Building Systems for all your in-place concrete requirements. We work with many local general contractors and developers as a concrete sub-contractor. If your project requires reinforced spread footings, piers, retaining walls and slabs on grade and on deck give Volunteer Building Systems a call, and you will understand why we “Build relationships… One building at a time.”