FAQ’s
As the leading concrete contractors in Waihi and the surrounding areas, we know that local homeowners and developers have specific questions about the durability and finish of their projects.
Below, Rex Podmore, who brings over 20 years of local concreting expertise, answers the most common questions regarding driveways, patios, and industrial slabs in the Bay of Plenty.
FAQs
WHY DOES CONCRETE CRACK?
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Concrete is a durable material, but it is also a natural product subject to physical and environmental stresses. Understanding why it cracks can help homeowners and builders set realistic expectations for their projects.
The primary reasons concrete develops cracks include:
The Natural Drying and Shrinkage Process
As concrete cures, the water used in the mix evaporates. This causes the slab to undergo shrinkage, which creates intense internal pressure. If this tension isn't relieved—typically through strategically placed expansion cuts or control joints—the concrete will naturally "snap" or crack to release that stress.
Substrate and Ground Movement
The stability of a concrete slab depends entirely on what is underneath it. Substrate movement, such as soil settling, erosion, or shifting due to moisture changes, can remove support from sections of the slab. Because concrete is rigid and lacks flexibility, it cracks when the ground beneath it moves.
Does reinforcing mesh prevent concrete cracks?
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While reinforcing mesh is required for vehicle crossings, it is optional for standard driveways.
Mesh provides structural integrity and can assist in preventing cracks from widening, but it doesn't guarantee a crack-free finish. We can provide quotes with or without mesh based on your budget and requirements.
Brownmore Concrete strongly recommends the use of mesh.
How can I prevent my new concrete from cracking?
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The best thing you can do is wait 5–7 days before driving a car on it.
In the hot Bay of Plenty summer, we recommend "curing" your concrete by lightly wetting it with a hose periodically.
This keeps the temperature down and slows the drying process, reducing the risk of heat-induced cracks.
How long until I can walk or drive on my new concrete?
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Drying times depend on the weather and temperature, but general guidelines are:
Walking: 24 – 48 hours.
Driving (Cars): 5 – 7 days.
Heavy Machinery: Longer durations are required.
Note: While we use barrier tape and signage, Brownmore Concrete cannot be held responsible for footprints (pets/children) or debris once we leave the site.
How thick should a concrete driveway be in New Zealand?
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For most residential driveways, we recommend a minimum thickness of 100mm.
The structural capacity of your driveway is directly tied to this thickness. If you plan on having heavier vehicles or machinery on-site, increasing the thickness beyond 100mm will significantly improve the load-carrying capacity and longevity of the slab.
Can you guarantee my concrete won’t crack?
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Unfortunately, no contractor can give a 100% guarantee.
Because concrete is a natural product, all hardened slabs have a tendency to move.
However, Rex and the team take every professional precaution, including proper site prep and precision cutting, to minimise this risk.
Why does my new concrete look patchy or blotchy?
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Concrete is a natural product, and variations in colour are normal.
As the concrete undergoes the curing process and moisture evaporates, it can temporarily appear patchy. This usually evens out as the slab fully matures.
what concrete finishes does brownmore concrete offer
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We provide a variety of finishes tailored to both aesthetics and safety:
Soft Broom Finish: Ideal for paths and driveways; provides excellent grip underfoot.
Steel Trowel Finish: A flat, smooth surface primarily for house floors. Note: This has low slip resistance.
Mag Float Finish: Offers a unique texture where extra grip is required.
Power Float: A machine-burnished finish used for harder, more durable house slabs.
Are expansion cuts necessary for concrete driveways?
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Yes.
We use expansion cuts to provide "weak points" that allow the concrete to shrink and relieve pressure. This directs any movement into the cut rather than allowing random cracks to form across your patio or driveway.
While they significantly minimise risk, they are not a 100% guarantee against random cracking.
Need aN ESTIMATE?
If you have a project in Waihi, Waihi Beach, Coromandel, Waikato or the surrounding Bay of Plenty region, talk to a local expert.
Call Rex today on 027 285 5489 to discuss your next residential, rural, or community project.
Check out our PRICING for more information.