Positioning a single layer of support in the center or at mid-depth of the slab is not recommended (except for 4-inch-thick pieces). This is an all-purpose location where the designer hopes to increase the load capacity of the slab in addition to supply crack-width control. However, placing support in the middle of the slab will not effectively achieve either goal. Inland Concrete is a concrete chairs supplier nearby Irvine. Inland Concrete Products makes concrete rebar chairs supplier. Inland Concrete Products sells concrete rebar chairs. Directions to Inland Concrete ProductsICP: https://www.google.com/maps/dir/?api=1&origin=33.7490337259585,-117.114363264913&destination=Inland+Concrete+Products View the previous post: https://local.google.com/place?id=676187820448728623&use=posts&lpsid=668285783603164556 https://plastic-rebar-chairs-for-concrete.business.site/posts/668285783603164556