Best way to lay wire mesh sheets

The plan for the 4" structural slab in my garage calls for #4 rebar dead center of the slab and 10/10 (W1.4/W1.4) wire mesh in the top third (about 1" below the surface). I've asked the builder to use flat sheets as opposed to a roll to ensure the mesh lays flat. Since the mesh is 6"x6", I imagine it can be difficult if not impossible for the workers to walk on the elevated mesh without damaging it, tripping, etc. Is it acceptable to embed the sheets in sections as they pour? Or rather place each sheet just prior to pouring that particular section? I suppose it's probably easier to place each sheet just prior to pouring each section rather than trying to push the mesh into the concrete from above. One issue I see with this approach is the mesh will likely end up in the middle of the slab directly on top of the rebar. BTW, the rebar will be elevated using 2" Prolok rebar and mesh chairs. Maybe they could attach 3" Prolok chairs to each mesh sheet ahead of time so they can place the sheets as needed and they will end up at the proper height? Do the sheets need to be fastened together, or can they simply be laid in place? Or even better, maybe lay all the sheets ahead of time using 3" chairs and only leaving out the middle section so they have a place to walk, then they could lay the remaining sheets as they work their way back to the door.