Placing concrete expansion joints is a necessary step when installing concrete slabs because they allow room for movement. The suggested distance between expansion joints is 10 feet. They should be placed at least this close together to ensure that the concrete slabs do not crack or break. Of course, this distance can be less if the slab that you are working on is not very large. Concrete expansion joints can be placed at any specific distance within a slab, but the maximum distance is 10 feet from one to another, or from the edge of the slab to an expansion joint.