Everyone needs a driveway, right? But what do you do if your property doesn't have a proper one, or it is time to update that loose metal? Often forming a new crossing onto the road or a new driveway is a condition of a resource consent, especially if you’re subdividing.
It is not as easy as popping to Mitre 10 and grabbing a bag of ready mix concrete. There are some considerations that have to go into laying a concrete driveway. So, in this blog, we are going to take a look at the materials and process involved in laying the concrete, including reinforcing, pouring, and drying time.
What’s involved in laying a concrete driveway?
Conditions and standards: before you start work on a crossing or driveway, make sure you have the right consents, permits and are working in accordance with the right Standards. Your local Council will usually have requirements about how these have to be constructed, and often these are reflected in your resource consent conditions. If you don’t construct them properly you risk the council not “signing off” the work.
Also check that you don’t breach any district planning rules. For example, are you working near a stream or do earthworks for the driveway go through the roots of protected trees? These could trigger the need for a resource consent. Always plan and check before you start!
Construction materials: there are many materials available that are suitable for constructing driveways, but the most commonly used is concrete. Concrete is made from three basic things – water, cement (the binding agent), and an aggregate. The aggregate is what makes up most of the volume of the concrete. It is the particulate material (rock, gravel, sand) that the cement binds together.
There are also other popular options for constructing a driveway including gravel, asphalt, and paving stones. But concrete is often used because it’s very versatile. It can be stamped or imprinted with patterns before it sets, which replicates the texture of stones or bricks. This is an affordable and low maintenance option.
Preparing, reinforcing, and finishing: before concrete is poured, it is important to properly prepare and reinforce the area. This helps to prevent cracking and premature wear and tear. Any grass, stones or other obstructing materials will need to be cleared away. Slim wooden panels (called ‘forms’) are used to outline the boundary of the driveway.
The first step is a 4 to 6 inch base layer of gravel added to the driveway area. Then you add the reinforcement component on top of the gravel. This usually consists of steel or a rebar (reinforcing bar) grid being laid in a criss-cross pattern. Rebar is made from various grades and alloys of steels. It is made with ridges so that the concrete will easily bond to it. By using rebar to increase the strength of the concrete, you can reduce the amount (thickness) of concrete needed and reduce the risk of breaking and cracking. This will help the driveway to last longer and reduce your maintenance costs.
Once the reinforcement is done, the concrete will be poured and smoothed. The concrete will then be floated, which is a finishing process that brings cement and finer aggregate particles up to create the final surface of the driveway. If you are going to add imprints or colours to the driveway that would also be done at this time.
Concrete doesn’t actually “dry”. Instead, it undergoes a chemical process called curing. This is the slow process of the concrete strengthening and hardening and is the last stage of installing a concrete driveway.
Other tips
Temperatures: don’t pour concrete at the hottest time of day, or when it is too cold. The ideal temperature for curing is about 20 degrees Celsius. You should not install a concrete driveway in temperatures under 5 degrees Celsius, as this can lead to curing and setting problems.
Time: concrete will be hard within 24 – 48 hours, but the curing process is slow and the concrete won’t be at full strength until around a month after it is installed. After a week, the concrete will be at about 70% strength and you can park your car on it after this time. If you have heavy vehicles you should not park them on your new driveway until after the first month.
Usually pouring a driveway is left to the specialist, but that doesn’t stop you from looking at smaller areas yourself.
Have a development in mind?
If you have any questions about the planning aspects or resource consent at your property then get in touch with the team here at Planning Plus. We have over 42 years of planning experience and will provide you with honest advice about your proposal. You can contact us on 09 427 9966 or hello@planningplus.co.nz.
Disclaimer As with all our blogs, the information detailed here is general in nature and meant as a preliminary guide only. This should not be substituted for your own investigations or use of your own professional’s. Planning Plus is not liable for any errors or omissions.
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