Questions to Ask a Concrete Contractor for a Driveway or Patio
For homeowners collecting bids on a driveway, patio, slab or sidewalk. These 20 questions cover mix strength, base prep, reinforcement, joints, curing and warranty, so you can compare quotes on substance instead of price alone.
20 questions, each with the reason to ask it · includes a conversation guide
The questions
Open any question to see why it works.
- 1
What kind of concrete work makes up most of your business, and have you poured a project like mine in the last year?
A crew that pours foundations all week is not automatically good at a stamped patio, and finishing is a separate skill from placing. Recent, similar work is a better signal than total years in business.
- 2
Are you licensed for this work in my city, and can you email me your liability and workers compensation certificates?
Certificates should come straight from the insurer with current dates, not as a photo of an old card. If a worker is hurt on your property without workers comp coverage, the claim can land on your homeowners policy.
- 3
Can you give me addresses of two or three pours you did at least three years ago that I can drive by?
Fresh concrete almost always looks good. Slabs that are three or more winters old show whether the base settled, the joints held, and the surface is spalling or scaling.
- 4
Will your own crew do the pour and the finishing, or is any of it subcontracted?
Many companies sell the job and hand the flatwork to a finishing crew you never met. You want to know who is actually holding the trowel and who is accountable if the surface goes wrong.
- 5
Who is my point of contact on pour day, and will a supervisor be on site while the trucks are there?
Concrete decisions cannot wait: slump, timing of the first pass, when to start floating. A named person on site means questions get answered in the ten minutes they matter rather than after the slab sets.
- 6
How thick will the slab be, and what base are you putting under it?
Four inches over four to six inches of compacted gravel is typical for a walkway or patio, while a driveway that sees trucks or an RV usually wants five to six inches and thickened edges. The answer tells you whether they priced the job or just the square footage.
- 7
How will you prepare and compact the subgrade, and what do you do if you hit soft or organic soil?
Most driveway failures start below the concrete, not in it. Listen for plate compactor or roller passes in lifts, and for a plan to dig out and replace soft spots rather than pour over them.
- 8
What mix strength are you ordering, and will you leave me the batch tickets from the trucks?
Ready mix is ordered by PSI, commonly 3000 to 4000 for residential flatwork, with air entrainment where there are freeze and thaw cycles. Batch tickets are your only proof that what arrived is what you paid for.
- 9
Are you using rebar, welded wire mesh, or fiber, and how will you hold it at the right height in the slab?
Reinforcement lying on the gravel does nothing. Ask about chairs or dobies that keep steel roughly in the middle of the slab, and whether mesh gets pulled up mid pour, which rarely works well.
- 10
What slope and drainage plan are you building in, and where will the water end up?
Flatwork needs roughly a quarter inch of fall per foot to shed water away from the house. Ask them to walk the grade with you and point at the low spot, since a patio that drains toward a foundation causes far more expensive problems than a rough finish.
- 11
Where will the control joints go, how deep will they be cut, and will you saw them or tool them?
Joints tell the concrete where to crack. Spacing is usually two to three times the slab thickness in feet, cut a quarter to a third of the depth, and saw cutting within the first day is a sign of a crew that plans cracks instead of hoping.
- 12
How will the slab meet the house, existing driveway, and any posts or drains?
Isolation and expansion joints at fixed objects let the slab move without cracking or pushing. Vague answers here often show up later as a crack running straight off a corner of the foundation.
- 13
What surface finish are you recommending, and how slippery will it be when wet?
A broom finish grips, a smooth steel trowel finish is a hazard outdoors, and stamped or exposed aggregate changes both traction and price. Ask to touch a sample panel rather than choose from a photo.
- 14
Do you allow water to be added at the truck, and how do you control slump on site?
Extra water makes concrete easier to spread and permanently weaker, with more shrinkage cracking and dusting. A contractor who says no or who uses a plasticizer instead is protecting your slab rather than the crew's afternoon.
- 15
How will you cure the concrete, and when should it be sealed?
Curing with water, blankets or a curing compound for the first several days drives most of the final strength. Sealer usually waits about a month, so anyone offering to seal it tomorrow is selling something.
- 16
What is your plan if pour day turns out to be rainy, over ninety degrees, or near freezing?
Heat, wind and cold each change the mix and the finishing window, and pouring anyway is how surfaces get scaled or crazed. You want to hear specific tactics such as rescheduling, early starts, blankets or hot water in the mix.
- 17
When can I walk on it, park a car on it, and drive something heavy on it?
Typical guidance is a day or so for foot traffic, a week for cars, and closer to a month for heavy loads. Getting real numbers up front prevents the argument that starts when someone parks a loaded trailer on a five day old driveway.
- 18
What cracking do you consider normal, and what would bring you back to fix it at no charge?
All concrete cracks, so the honest answer distinguishes hairline shrinkage from displacement, settlement or joints that failed. Their line between the two is the real content of the warranty.
- 19
Line by line, what does the bid include and what is excluded?
Demolition, haul away, permits, forms, base material, reinforcement, saw cutting, sealer and final cleanup are the items that turn a low bid into a change order. Ask for the exclusions in writing so you can compare quotes fairly.
- 20
What is the payment schedule, and will you provide lien releases from your suppliers and crew?
A modest deposit with the balance on completion is normal, and a demand for most of the money up front is the clearest warning sign in this trade. Unpaid ready mix suppliers can put a lien on your house even after you have paid the contractor in full.
Hiring a Concrete Contractor Without Regret
Practical guidance for the conversation itself.
How to Compare Bids Fairly
How to Compare Bids Fairly
Give Every Contractor the Same Scope
Write down square footage, thickness, mix strength, reinforcement, finish and who handles demolition, then hand that sheet to each bidder. Otherwise you are comparing a four inch slab on bare dirt against six inches on compacted gravel and calling one of them expensive.
Insist the Spec Lands in the Contract
PSI, slab thickness, base depth, reinforcement type, joint layout and cure method belong in the written agreement, not in a conversation in your driveway. If a contractor resists putting numbers on paper, that is your answer.
Look at Old Work, Not New Work
Ask for jobs from three or more years ago and walk them. Check joints for spalled edges, run your hand over the surface for dusting, and look for cracks that have opened or shifted rather than hairlines.
Be Home for the Pour
You do not need to supervise, but you should see the base before concrete covers it, confirm reinforcement is up on chairs, and collect the batch tickets. After the trucks leave, none of that is verifiable.
Numbers Worth Knowing Before the Meeting
Numbers Worth Knowing Before the Meeting
- Slab thickness: about 4 inches for patios and walkways, 5 to 6 inches for driveways that carry trucks or RVs
- Base: 4 to 8 inches of compacted crushed gravel, placed in lifts, not loose fill
- Mix strength: commonly 3000 to 4000 PSI for residential flatwork, with air entrainment in freeze and thaw climates
- Slope: roughly 1/4 inch of fall per foot, always away from the house
- Control joints: spaced in feet at about 2 to 3 times the slab thickness in inches, cut 1/4 to 1/3 of the depth
- Curing: keep it moist or covered for the first several days, since that is where most strength comes from
- Sealing: usually about 28 days after the pour, not the next morning
- Loading: foot traffic in a day or two, cars in about a week, heavy loads closer to a month
- Deposit: a modest percentage up front, with the balance due at completion
Warning Signs Worth Walking Away From
Warning Signs Worth Walking Away From
Cash Only and a Big Deposit
Requests for most of the money before the pour, cash only pricing, or no written contract are the pattern behind most abandoned concrete jobs. Pay by a traceable method against a schedule tied to milestones.
A Bid With No Numbers On It
One line reading new concrete driveway with a price gives you nothing to hold anyone to. Thickness, PSI, base and reinforcement are exactly the items that get quietly reduced to hit a low bid.
Water Added Freely at the Truck
If the crew hoses down the mix to make it flow, expect a weaker, dustier surface and more shrinkage cracks within a year. Soupy concrete spreads easily and fails early.
Pouring Through Bad Weather Anyway
A contractor unwilling to reschedule around rain, a hard freeze or extreme heat is prioritizing their calendar over your slab. Surface scaling and crazing from a bad weather pour cannot be repaired, only ground down or replaced.
No Answer on Joints or Drainage
If nobody can tell you where the joints go or where water will run, those decisions get made improvised on pour day. That is how you end up with random cracks and a patio that drains at your foundation.