Why guarantees and warranties matter when hiring a concreter A good concrete job should last for years, but concrete is only as good as the design, preparation, materials and workmanship behind it. If something goes wrong, it is not always obvious whether the problem sits with the concreter, the concrete supplier, the site conditions, or even another trade that prepared the base or drainage.
That is why it pays to understand three different layers of protection before work starts:
- a **workmanship guarantee** from the concreter - any **product warranties** from the concrete supplier or manufacturer - your rights under the **Consumer Guarantees Act 1993 (CGA)**
For New Zealand homeowners, this is especially important because concrete work often sits outdoors and is exposed to local conditions such as heavy rain, clay soils, coastal salt air, ground movement, and summer heat. A driveway, path, slab, retaining edge or patio can fail for reasons that are partly environmental and partly human.
What a concreter should usually guarantee A professional concreter should stand behind the quality of their own labour and installation methods. A workmanship guarantee is not the same as a product warranty, and it should clearly say what the concreter is promising to fix if their work is defective.
Typical workmanship guarantees may cover issues such as:
- poor finishing, including obvious trowel marks, inconsistent broom finishes, or surface defects caused by poor technique - incorrect levels or falls that cause ponding when the design was meant to shed water - cracking caused by inadequate base preparation, poor joint placement, or rushed curing - edge failure from improper formwork or early removal of supports - honeycombing or blowouts caused by poor placement or vibration - sealing faults if the concreter supplied and applied the sealer
A workmanship guarantee should also explain what is **not** covered, such as:
- movement caused by subsidence, earthquakes, flooding, tree roots, or drainage failures outside the concreter’s control - damage from vehicle overloads, heavy machinery, or impacts after completion - normal hairline shrinkage cracking that is common in concrete and not a structural defect - colour variation, minor surface blemishes, or texture differences within an accepted tolerance
A trustworthy concreter will not promise that concrete will never crack. Concrete is a rigid material and some shrinkage cracking is normal, especially with temperature changes and large slabs. What matters is whether the slab was designed and installed to industry-accepted standards and whether any cracking is beyond what would reasonably be expected.
Product warranties: what they do and do not cover If your project uses a concrete admixture, curing compound, reinforcing system, sealer, or a proprietary decorative product, there may be a manufacturer’s warranty attached to that product. Product warranties are separate from the concreter’s labour guarantee.
Examples include:
- decorative coatings or coloured systems - concrete sealers - reinforcement products - fibre additives - pre-mixed concrete supplied by a ready-mix plant
A product warranty usually covers manufacturing defects in the product itself, not incorrect installation. For example, if a sealer fails because the concrete was not dry enough when applied, that is more likely an installation issue than a product defect.
In practice, homeowners should ask:
- who is supplying the product - whether the warranty is from the manufacturer, distributor, or installer - what the warranty period is - what evidence is needed to make a claim - whether the warranty requires specific maintenance, such as resealing every few years
Keep in mind that some warranties are conditional. If the concreter does not follow the product’s instructions exactly, the warranty may be reduced or voided. That is another reason to choose a tradesperson who understands the product and can explain how they will use it.
The Consumer Guarantees Act in New Zealand The Consumer Guarantees Act gives consumers strong rights when they buy goods and services from a trader in the ordinary course of business. In most domestic concreting jobs, the CGA applies.
For services, the Act generally requires that the work be:
- carried out with reasonable care and skill - fit for a particular purpose that you made known to the trader - completed within a reasonable time if no timeframe was agreed - charged at a reasonable price if no price was agreed
That means if you hire a concreter to build a driveway that can handle family vehicles, or a slab for a shed, they must use reasonable care and skill and deliver something fit for that purpose.
The CGA is important because it applies even if the contractor’s written warranty is limited. A short workmanship guarantee does **not** override your statutory rights.
However, the CGA is not a blank cheque. If the problem was caused by something outside the concreter’s control, or by a design you insisted on despite warnings, your remedies may be limited. Good records matter.
What to ask for before you sign Before work starts, ask for a written quote or contract that sets out the guarantee position clearly. This avoids arguments later about what was promised.
A useful quote or contract should cover:
- the exact scope of work - slab thickness, reinforcement, and any mesh or bar details - surface finish and colour - joint layout and saw-cut timing - drainage and falls - curing method and aftercare - whether sealing is included - warranty or guarantee terms - how defects will be assessed and fixed
Ask these questions early:
1. **What workmanship guarantee do you provide?** 2. **How long does it last?** 3. **What defects are covered?** 4. **What is excluded?** 5. **Do you provide the guarantee in writing?** 6. **Will you use any products with separate manufacturer warranties?** 7. **Who is responsible if the concrete supplier’s product is defective?** 8. **Do you have public liability insurance?**
It is also sensible to get at least two or three written quotes. That helps you compare not just price, but the quality of the guarantee, the proposed method, and whether the contractor seems to understand local ground and weather conditions.
How NZ concrete jobs can fail, and why that matters for warranties Many disputes about concrete are really disputes about cause. Here are some common failure points and who may be responsible.
| Problem | Possible cause | Who may be responsible | |---|---|---| | Random cracking | Normal shrinkage, poor curing, insufficient joints, poor base | Could be normal, or workmanship issue if avoidable | | Ponding water | Incorrect falls, poor level setting | Concreter, or sometimes designer/specifier | | Surface dusting or weak surface | Overworking surface, excess water, poor curing | Concreter or mix/supplier issue | | Spalling near edges | Poor compaction, no reinforcement, salt exposure, de-icing products | Concreter, design issue, or environmental exposure | | Discolouration | Batch variation, weather, curing differences | Often not a defect unless severe or caused by poor workmanship | | Settlement or voids | Poor base preparation, soft ground, water movement | Concreter, site conditions, or another trade’s work |
In New Zealand, site conditions vary a lot. A job in a stable urban section is not the same as a driveway on a sloping clay site, a coastal property, or an area with recent fill. Good contractors should flag these risks before quoting and may recommend extra base work, drainage or expansion detailing.
What records to keep If you ever need to make a claim, good paperwork will make the process much easier. Keep:
- the written quote and contract - emails, texts, and messages discussing the job - product names, batch numbers and sealer details if provided - photos before, during and after the work - payment records and invoices - any maintenance instructions - notes of when issues were first noticed
If the concreter gives verbal assurances, follow up in writing. A simple email can help: “Just confirming you will provide a five-year workmanship guarantee covering defects resulting from installation faults, excluding normal shrinkage cracking and external ground movement.”
If the work is faulty: what recourse do you have? If you think the concrete work is defective, act promptly. Don’t wait for the problem to get worse.
Start with these steps:
1. **Notify the concreter in writing** and describe the defect clearly. 2. **Include photos** and the date you first noticed the problem. 3. **Ask for a site inspection** and a written response. 4. **Give them a reasonable chance to fix it** if the problem is repairable. 5. **Keep a timeline** of all communications.
Under the CGA, if the work has failed to meet the guarantee of reasonable care and skill, you may be entitled to a remedy. Depending on the issue, this could mean repair, rework, a reduction in price, or in serious cases recovery of the cost to have the problem fixed by someone else.
If the contractor refuses to respond or disputes responsibility, you may need to escalate. Options can include:
- consumer mediation or dispute resolution services - the Disputes Tribunal, for eligible claims up to the Tribunal limit - legal advice for larger or more complex defects
If the issue could involve structural safety, drainage failure, or related building work, you may also need input from the local council, an independent engineer, or another qualified building professional.
When consent or other regulated work may be involved Pure concrete placement is not generally the same as licensed electrical, gasfitting, plumbing or drainlaying work. But many concreting projects sit beside or around regulated work.
Be alert to the following:
- **building work may require a building consent** from your local council, especially for larger slabs, retaining structures, additions, or work affecting structural elements - **drainage modifications** may trigger council requirements or involve drainlaying work regulated under the PGDB framework - **electrical work** near the site, such as outdoor lighting or pumps, must be carried out by a registered electrician where required - **gasfitting** or **plumbing** changes connected with the project must be done by appropriately licensed tradespeople
A good concreter will know when to flag these issues and when to recommend you check with the council or another licensed trade before work proceeds.
Red flags to watch for Not every contractor offers the same level of protection. Be cautious if a concreter:
- refuses to provide anything in writing - says there is “no warranty at all” - promises that the slab will “never crack” - will not explain jointing, curing, or drainage - asks for a large cash deposit without a clear contract - is vague about insurance, experience, or product brands - discourages you from getting multiple quotes
These are often signs that the job is being sold on price rather than quality. In concrete work, a cheap quote can become expensive if there is no meaningful recourse.
The bottom line for homeowners A good concreter in New Zealand should offer a clear workmanship guarantee, use products with any relevant manufacturer warranties, and be willing to explain your rights under the Consumer Guarantees Act. The best protection is a written quote that spells out the scope, the standard of work, what is covered, and what is excluded.
Before you hire, compare more than price. Check references, confirm insurance, ask about cure times and aftercare, and make sure any consent or related regulated work is handled properly. If the concrete is faulty, act quickly, document everything, and put your complaint in writing.
The right contractor will not be defensive about guarantees — they will see them as part of doing the job properly.