The great debate on whether to use rebar or number 10, 6 x 6 wire mesh in a concrete slab may go on forever. However, the consensus of opinion seems to be that wire mesh sheets, not rolls, should be used where slab thickness is between four and six inches and rebar should be used in slabs with thicknesses of eight inches or more. The wire mesh should be raised to between one third and one half of the thickness of the slab from the bottom. This can be done by using supports prior to the pour or by raising the mesh after the pour.
Individuals who find that their concrete slabs are cracking with the use of wire mesh may not be compacting the subsurface adequately before pouring the concrete slab. Secondarily, a spacer to help with stress cracks should be placed every 10 feet.
The use of fibers in concrete does not replace wire mesh or rebar. Fibers will aid in preventing surface cracking, but do not provide much in the way of support for thermal expansion or shrinkage of the entire slab.