Getting quotes for a concreting job — whether it's a driveway, patio, shed slab, or path — is one of the most important steps you'll take before work begins. Asking the right questions upfront helps you compare quotes fairly, understand exactly what you're paying for, and avoid disputes down the track. Here's a practical guide to what NZ homeowners should be asking.
How Many Quotes Should You Get?
As a general rule, aim for at least three quotes from different concreters. This gives you a realistic sense of the market rate in your area and helps you spot any outliers — either suspiciously cheap or unusually expensive. Prices can vary significantly depending on your region, the complexity of the job, and current demand for materials and labour.
Questions to Ask About the Scope of Work
Before comparing prices, make sure every contractor is quoting on exactly the same job. Ask:
- What is included in the quote? Does it cover excavation, formwork, reinforcing steel (mesh or rebar), concrete supply, finishing, and clean-up?
- What concrete mix will be used? For driveways, a minimum of 25 MPa concrete is generally recommended in NZ. For heavier vehicle loads, 30 MPa or higher may be appropriate. Ask the concreter to justify their specification.
- What thickness is being quoted? A standard residential driveway is typically 100 mm thick, while a shed slab may be 100–150 mm. Thinner pours can crack prematurely.
- Will reinforcing be used? Ask whether the quote includes steel mesh (F72 or F82) or fibre reinforcement, and where it will be positioned in the slab.
- How will the surface be finished? Options include broom finish, exposed aggregate, brushed, or polished. Make sure the finish you want is specified in writing.
- Will control joints (saw cuts) be included? These are essential for managing cracking and should be part of any quality job.
Questions About the Contractor
Not all concreters have the same level of experience or professionalism. Ask:
- How long have you been concreting in NZ? Experience with local soil conditions, climate, and council requirements matters.
- Can you provide references or photos of recent work? A reputable concreter should be happy to share examples.
- Are you a member of any trade associations? While not compulsory, membership in organisations like Certified Builders or similar groups can indicate a commitment to quality.
- Do you use subcontractors? If so, who is responsible for the quality of their work?
- Are you and your team covered by public liability insurance? This protects you if something goes wrong on your property. Ask for a copy of their certificate of currency.
Questions About Consents and Compliance
This is an area many homeowners overlook. In New Zealand, some concreting work may require a building consent, depending on the size and nature of the project. For example, a large retaining wall with a concrete footing, or a slab that forms part of a habitable building, may need consent under the NZ Building Code.
- Does this job require a building consent? Ask your concreter, but also check with your local council — ultimately it's your responsibility as the property owner.
- Will the work comply with NZ Building Code requirements? Relevant clauses include B1 (Structure) and E1 (Surface Water) for drainage around slabs.
- Who is responsible for obtaining consent if required? Make sure this is clearly stated in the contract.
For guidance on Schedule 1 exemptions (work that may not need consent), visit MBIE Building Performance and confirm with your council.
Questions About the Quote Itself
Once you have quotes in hand, dig into the detail:
- Is the quote fixed-price or an estimate? A fixed-price quote gives you cost certainty. An estimate can change if conditions vary (e.g., unexpected rock or poor ground).
- What are the payment terms? Be cautious of contractors asking for large upfront deposits. A reasonable deposit (often 10–20%) is normal, with progress payments tied to milestones.
- What is the timeline? When will work start, and how long will it take? Concrete needs adequate curing time — typically at least 7 days before light foot traffic and longer before vehicle use.
- What happens if the weather is bad? Concrete should not be poured in heavy rain or extreme heat without precautions. Ask how the contractor manages weather delays.
- Is GST included in the price? Always confirm whether quoted prices are GST-inclusive or exclusive.
Questions About Aftercare and Warranties
- What curing method will be used? Proper curing (using curing compound, wet hessian, or plastic sheeting) is critical to concrete strength and durability.
- Do you offer a warranty on your workmanship? Ask what is covered and for how long. Note that concrete can develop minor surface cracking over time — ask what level of cracking is considered acceptable.
- What sealer (if any) will be applied? Sealing can protect the surface, especially for exposed aggregate or decorative finishes.
Comparing Quotes Side by Side
Once you have your quotes, use a simple table to compare them:
| Item | Quote A | Quote B | Quote C |
|---|---|---|---|
| Concrete strength (MPa) | |||
| Slab thickness (mm) | |||
| Reinforcing included? | |||
| Surface finish | |||
| Control joints included? | |||
| GST included? | |||
| Fixed price or estimate? | |||
| Warranty offered? |
This makes it easy to see where quotes differ — and to go back to contractors with follow-up questions.
When to Call a Professional
Concreting is not restricted work under NZ law in the same way that electrical or plumbing work is, but it is a skilled trade. Poor concrete work can be expensive to fix and may affect your property's drainage, structural integrity, or resale value. For anything beyond a small garden path, we strongly recommend hiring a qualified, experienced concreter. You can find local concreting professionals on tradedirectory.co.nz.
If your project involves retaining walls over 1.5 m, structural slabs, or drainage works, you may also need input from a licensed building practitioner — check the LBP register for qualified professionals.
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