What decides the cost of a concrete driveway, patio or slab?

Driveways, patios, and slabs usually run $9 to $12 per square foot. Footings we quote per job.

Our estimates are free. We come out for a free estimate, then send a written quote.

The International Residential Code requires slab-on-ground floors to be at least 3.5 inches thick.

The City of Phoenix driveway policy says concrete for residential driveways in the right-of-way is 6 inches thick.

The IRC says the area under a slab must be cleared of vegetation, top soil and foreign material, and that fill must be compacted for uniform support.

Where the slab is below grade, the code calls for a 4-inch base course of clean graded granular material, with an exception for some well-drained soils.

The City of Phoenix lists a change of drainage conditions on your lot as work that needs a permit. The city's driveway policy also calls for an off-site flow analysis and erosion protection on driveways for roads with no sidewalk, curb and gutter, or ribbon curb.

For driveways longer than 10.5 feet in the right-of-way, the policy says concrete finishes other than rough broom require a maintenance agreement from the city's Street Transportation Department.

The Arizona Registrar of Contractors says permits are the responsibility of the property owner, and that many contractors include the cost of obtaining them in the contract.

It recommends written estimates from at least three contractors, with a detailed description of the project, the price and the responsibility for permits spelled out.