Base preparation
Excavation depth, removal of organic or unstable material, imported aggregate, and compaction. On clay soil this is the difference between a slab that lasts and one that settles at the edges within a few years.
Thickness and reinforcement
A walkway and a driveway carrying vehicles are not the same slab. Thickness, mesh or rebar, and fiber all get specified for the actual load.
Joint layout
Concrete will crack. Control joints decide where. Their spacing and depth should be planned for the shape being poured, not cut arbitrarily after the fact.
Removal and disposal
Breaking out and hauling away existing concrete is real cost, and it's a common source of bid difference — one includes it and one assumes it's separate.
Access and site conditions
- How close a truck can get to the pour
- Whether pumping or wheeling is required
- Slope and how much forming it requires
- Protection of adjacent landscaping and hardscape
Finish and drainage
Broom, exposed aggregate, stamped, or stained finishes carry different labor. And slope has to be right — a driveway that sends water toward the garage was cheaper to form and much more expensive to live with.
- Base preparation is the largest hidden variable in a concrete bid.
- Thickness and reinforcement should match the actual load.
- Joint placement controls where cracking happens.
- Confirm whether removal and disposal are included.