You'll find garage floors around here with no steel at all, floors with mesh lying uselessly at the bottom of the slab, and floors with a proper rebar grid. Only one of those was built on purpose.
What steel does in a floor
Rebar doesn't prevent cracks — shrinkage and ground movement cause those, and steel can't stop either. What rebar does is hold cracks tight. A hairline crack in a reinforced slab stays hairline: the panels can't separate, shift vertically, or work against each other under wheel loads. In an unreinforced slab, the same crack widens, faults into a step, and grows every winter.
On a floor that carries vehicles across it daily, that difference is the whole service life.
Why garages specifically
Garage slabs combine several risk factors: they sit on backfilled ground inside foundation walls (settle-prone), they take concentrated wheel loads in the same spots every day, and they see moisture and salt dragged in all winter. That's exactly the load case where reinforcement earns its keep.
We put a rebar grid on chairs in every garage floor — held mid-slab where it works, photographed before the pour covers it.
The upcharge question
On a lot of bids, rebar appears as an add-on line, which frames it as optional. We think that framing is backwards — the steel costs a small fraction of the job and determines how the floor ages. So it's not a line item on our quotes; it's just in there.
Comparing bids? Make sure you're comparing the same slab. A free on-site estimate gets you our full spec in writing.
Related service
Garage FloorsA flat, crack-controlled slab that drains right and carries what you park on it.