How do I find a good residential concrete contractor?

What flatwork is, and why the specialty matters

Flatwork is concrete that lies flat on the ground: driveways, patios, walks, steps, garage floors and pads. It looks simple, but many flatwork problems trace back to a few decisions made around the pour: the base, the mix, the joints and the curing. A crew that pours flatwork every week makes those calls by habit. A general handyman or a crew that mostly does foundations or walls may not.

Licensing: it depends on your city

There is no single national rule. In Ohio and Texas we found no state license for concrete flatwork, so cities fill the gap.

Place	What we found	Source
Ohio (state)	State license covers HVAC, refrigeration, electrical, plumbing and hydronics contractors only	[3]
Columbus, OH	All contractors need a city license or registration before pulling permits. A home improvement limited license covers residential sidewalks and driveway approaches and requires 1 year of hands-on experience	[4]
Cleveland, OH	Contractors must be bonded, insured and registered with the city; homeowners can call 216-664-2910 to verify	[5]
Cincinnati, OH	Home improvement contractors working on one to three family homes must register; proof of liability insurance is part of registration	[6]
Chicago, IL	The city licenses general contractors in classes by project size; Class E covers projects up to $500,000	[7]
Texas	We found no state license for concrete contractors. Dallas names plumbing and mechanical contractors as state-licensed and requires a licensed electrician for electrical work	[8]
Illinois (state)	We did not find a state license for concrete contractors; check with your city	n/a

Licensing rules change. Before you sign, call your city's building department and ask what license or registration the contractor needs for your exact job, and whether the work needs a permit. Driveway aprons and public sidewalks often need a separate right-of-way permit. See do you need a permit for concrete work.

The credential worth asking about: ACI flatwork certification

The American Concrete Institute runs a flatwork certification program for individual finishers^[1].

ACI level	What it takes	Valid for
Concrete Flatwork Associate	Written exam, about 50 questions, 70% to pass	5 years[1]
Concrete Flatwork Finisher	1,500 hours of on-the-job finishing experience, verified by employers, plus a performance exam	5 years[1]
Advanced Concrete Flatwork Finisher	Written exam plus either 1,500 hours and a performance exam, or 4,500 hours of experience	5 years[1]

Ask whether anyone on the crew that will pour your job holds one, and get the name. ACI's website has a "Verify a Certification" tool^[2]. Many good residential finishers are not certified, so treat it as a plus, not a requirement.

Questions that separate good bids

Ask each contractor the same questions and compare the answers. A contractor who knows the trade will answer without hedging.

1. How thick, and on what base? Ask about slab thickness and how the soil and base will be prepared and compacted.
2. What mix will you order? In freeze-thaw areas where deicers are used, NRMCA recommends exterior slabs with a specified strength of 4,000 psi, consistent with ACI 332, and air-entrained concrete with about 6% total air for common aggregate sizes^[10]. Where slabs are not continuously moist and no deicers are used, NRMCA's figure is 3,500 psi^[10].
3. Where will the joints go? NRMCA recommends joints no farther apart than 24 to 36 times the slab thickness, about 10 feet for a 4-inch slab, with a 15-foot maximum, and panels close to square^[9]. It also calls for isolation joints where a slab meets the house, steps or other fixed points^[9].
4. How will you cure it? NRMCA says curing should start right after finishing and typically continue 3 to 7 days^[11]. Ask what method the crew uses and what you need to do.
5. Who pulls the permit? The contractor should know the answer for your city.
6. What does the warranty cover? Get it in writing, including what happens if cracks appear.

More on this in questions to ask a concrete contractor and comparing two concrete quotes.

Where to find candidates

Good leads usually come from work you can see. Ask neighbors whose driveway or patio has held up for several years. Check your city's registered contractor list where one exists; Cincinnati's registration rules include a registered contractor lookup^[6]. Referral services, including this site, are paid by the contractors they refer. Ask any service how it is paid and who the contractor is before you share your details. You can read how we match homeowners with independent contractors.

Door-to-door offers and leftover concrete

Be careful with a crew that knocks on your door saying it has leftover concrete from a nearby job. Take time to check the license or registration, insurance and references.

If you do buy at your door, the FTC's Cooling-Off Rule gives you three days to cancel certain sales made at your home that are $25 or more, until midnight of the third business day. The seller must give you written notice of that right and cancellation forms^[12]. The rule has exceptions, so read the FTC's summary. Some states add their own rights.

When to call a pro

• Before you get flatwork bids for a slab that touches the house and shows cracks or sinking: call a structural engineer first.
• Your city requires a permit or right-of-way approval: hire a contractor who will pull it.
• Bids differ by more than you can explain: ask each contractor to price the same thickness, base, mix and joint plan.
• The job involves drainage, retaining walls or steep grades: ask for a contractor who handles that work, or bring in a civil engineer.