Steel in concrete slabs on ground is not intended to be structural, only to hold cracks closed tightly. For that reason, slabs are considered unreinforced even though most will have some temperature reinforcement.

Use individual reinforcing bars (like #4 rebar @ 18” oc) or sheets of wire mesh rather than rolls. The rolls of mesh are nearly impossible to get flat enough to position properly. Some contractors have recommended using heavier wire with wider spacing so workers can step through the mesh instead of trying walk on top-that may be possible with rebar but most mesh doesn’t have the wire spaced far enough apart to actually step through. Steel may or may not continue through the joints – check the plans to be sure.

Steel reinforcement in concrete slabs on ground does not increase the flexural strength of the slab and does not increase the ability to carry loads. The purpose of slab reinforcement is only to hold together any shrinkage cracks that develop between the joints. Reinforcement actually increases the number of cracks but keeps the cracks tight so the slab can continue to perform as intended.

With structural concrete, the steel is near the bottom of the cross section. But in slab on ground the reinforcement should be at or above the mid-depth of the slab-ideally 1/3 depth or 2 inches below the surface. Slabs shrink more at the top than at the bottom, meaning that the cracks are usually wider at the top, so that’s where to locate the reinforcement.

Do NOT try to hook the steel and pull it up into the proper position. Trying to lift yourself is nearly impossible. Also do not try to “walk it in” to the fresh concrete. Steel that has been walked on or not supported may end up in the very bottom of the slab. Steel in the bottom of the slab is useless.

Since vertical position of the steel is important, it must be supported during concrete placement. Use chairs (plastic or steel) to support the steel. The supports should be spaced so that the foot traffic will not move the reinforcement out of position.

Hope this was information you could use.