What is a concrete driveway?
A concrete driveway is made of aggregate (stones and gravel) bonded together by cement. The aggregate used can vary in size and appearance.
Concrete does have a bit of reputation of being drab, but its appearance can be livened up with the addition of coloured stones, concrete paint, or the application of stencils to create the appearance of pavers.
What’s the best use?
Concrete driveways are suitable for a wide range of applications, as the surface can be adapted for practical (i.e. different finishes for grip) and aesthetic needs (concrete can be finished in a number of colours or engraved).
What maintenance is required?
With a high quality installation, concrete needs very little maintenance. Ensure spills of oil, grease or petrol are removed as soon as possible to prevent stains forming and reseal the concrete every two years and your drive should look good for at least a decade, if not longer.
What are the minimum and maximum grades?
To ensure water drains, concrete driveways should have a fall of at least one percent away from the house and towards the street.
The grade should not exceed 1:4 within the property boundary. Note that in some areas, there are restrictions on how steep a driveway can be; be sure to check with your local council about these limitations.
Do concrete driveways need steel reinforcing?
Concrete driveways can be constructed without steel reinforcing, as it does not increase or decrease the load capacity – it merely prevents cracks widening should they occur.
How is it installed?
For non-reinforced concrete and standard passenger cars, concrete needs to be 100mm thick. For heavier vehicles, the required thickness increases to 130mm.
Installation of a concrete driveway will usually proceed as follows:
- Choose a cool, overcast day to pour your driveway – don’t proceed if there’s a chance of rain or frost. Very hot days should also be avoided.
- Excavate 200-300mm
- Create a base with hardcore of at least 150mm
- Cover with fine gravel and level it off
- Ensure good compaction with a vibrating plate or roller
- Install timber forms along the sides of the drive, with stakes at regular intervals and and at every join between timber forms
- Check the elevation to ensure uniform slab height
- Lay the concrete
- Insert shrinkage joints at least every 5-6m to avoiding cracks forming. You can also cut control joints. These will need to be done with 24 hours of pouring – sooner if the weather is hot.
- Keep vehicles off your drive for at least seven days. If the weather is quite cool, extend this by another 5 days.
What will a concrete driveway cost?
Factors that will alter the cost of your concrete driveway include:
- Size – the length and width
- The slope – the price increases as the slope does
- The appearance – plain concrete is cheapest. Add in colour, exposed aggregate or stencilling and the price will increase.
To ensure you get an accurate quote from your concreter or can put together an accurate budget, make sure you know all of the above items.
Many concreting companies have quote calculators on their website, making it quick and easy to get a quote.
Advantages and disadvantages of concrete driveways