Rebar vs wire mesh
Wire mesh is cheaper and faster for patios and walkways; rebar earns its cost on driveways, garages, and anything bearing vehicles. If you use mesh, pull it up into the slab during the pour — mesh walked to the bottom of the form is decoration, not reinforcement.
Placement beats quantity
Steel works in tension, and a slab's tension zone is the lower middle. A light grid properly chaired at 2 inches outperforms a heavy grid lying on the gravel. Budget for chairs — they're cents each and decide whether the rebar does anything at all.
FAQ
What size rebar for a 4-inch slab?
#3 or #4 (3/8 or 1/2 inch) at 12–18 inch spacing is standard for residential flatwork. Driveways and garage floors favor #4 at 12–16 inches.
Does rebar prevent cracking?
It controls crack width rather than preventing cracks — concrete shrinks as it cures and will crack; reinforcement keeps those cracks tight and the panels aligned. Control joints decide where the cracks happen.
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