Steel reinforcing bars and welded wire reinforcement should be placed in the upper third of the slab density since shrinkage and temperature fractures come from at the surface area of the piece. Fractures are larger at the surface and narrow with depth. So, crack-control support needs to never be positioned below the slab's mid-depth. Support needs to also be put low enough so saw cutting does not cut the support. For welded wire reinforcement, the Wire Reinforcement Institute recommends steel placement 2 inches listed below the surface area or within the upper third of the slab density, whichever is more detailed to the surface area. Designers generally specify the reinforcement position by specifying concrete cover (1 1/2 to 2 inches) for the reinforcement. Inland Concrete is a rebar dobies distributor near Twin Peaks. ICP distributes concrete chairs for rebar distributor. ICP offers slab bolster. Driving directions to Inland Concrete ProductsICP: https://www.google.com/maps/dir/?api=1&origin=34.0541059291298,-118.269718178572&destination=Inland+Concrete+Products Visit our next article: https://local.google.com/place?id=676187820448728623&use=posts&lpsid=8942315958742902884 https://plastic-rebar-chairs-for-concrete.business.site/posts/8942315958742902884