How Much Does a Concrete Slab Cost? [2024]

Before you build a house, garage or even a shed, you need to have a solid foundation for it. There is no more solid a foundation than a concrete slab, but it does add to the cost of the project.

So how much does a concrete slab cost? Generally, you should expect to pay anywhere from $75 to $110 per square metre to have a concrete slab laid. Factors that will impact the cost include the size and thickness of your slab, as well as how easy access is to your site.

Read this guide to concrete slab costs to find out more about:

• How concrete slab costs are calculated
• How much does a concrete slab really cost?
• Different types of concrete slab
• How to DIY a concrete slab
• Getting quotes from concreters

How concrete slab costs are calculated

The cost of concrete slab installation is usually calculated by the square metre (m2), but some concreters quote by the cubic metre (m3). Theoretically, you should be able to find out how much your slab is going to cost simply by calculating the square or cubic metres of the area you need covered and getting quotes from concreters for their concrete slab cost per m2 or m3.

The problem with this approach is that you might find a wide range of per metre charges. One source might say "from $40/m2" while another might advertise prices "from $50/m2" or more. The catch to these online prices is in the word "from". $40/m2 might be the lowest price a company charges, but the price you pay will usually be much higher.

When concreters calculate their square metre rates, they take several things into consideration:

• How thick does the slab need to be? A house concrete slab might be thicker than a slab for a shed. It will require more concrete and more labour, so the concrete slab cost per m2 will be higher.
• How big is the job? The size of the job can drastically change the concrete slab cost, because travel, set-up and other time-consuming details need to be factored into the quote.
• Are there any access issues? If access is easy, the per metre charge should be less. If access is difficult, they will have to charge more.
• Location: Market forces in your area or the distance between you and a concreting company's base of operations may factor into their quotes.

So when you compare the cost of concrete slab installation online, you have to ask yourself what they mean by "from" before you choose a company to pour your concrete.

How much does a concrete slab really cost?

On average, concrete slabs can cost anywhere from $75 to $110 per square metre. That's still quite a spread, but it gives you a starting point for comparing quotes.

If your slab is going on a flat block of land with easy access, expect the price to be on the lower end of the scale. If it looks like the concreter will have to use a concrete pump to pour the concrete, it will probably be on the higher end of the scale.

The size of companies you get quotes from can also affect the price. A smaller concreting company might charge less in order to compete and keep a steady flow of work coming in. Larger concreting companies sometimes prefer to focus on larger construction projects and charge a premium for small jobs.

The overall cost to install a concrete slab should be around:

• $7,500 to $11,000 for a standard 10x10 concrete slab
• $1,620 to $2,376‬ for a single garage (3.6m x 6m)
• $3,150 to $4,620‬ for a small shed (6m x 7m)
• $11,700 to $17,160 for a larger shed (12m x 13m)

However, not all slabs are priced equally. The thicker the slab, the more you should expect to pay, so the cost of a concrete slab for a shed will usually be less than a concrete slab for a house, because it will won't be as thick.

Different types of concrete slab

The above costs are for plain concrete, but how much a concrete slab costs also depends on the type of concrete you choose.

Your concrete slab cost will be higher if you choose reinforced concrete or a decorative finish such as coloured concrete, exposed aggregate (pebblecrete) or stamped or stencilled concrete.

You could save money on your project by choosing recycled concrete slabs made from recycled or reclaimed concrete.

 

How to DIY a concrete slab

DIY concreting will save you money on the cost of a concrete slab, since you won't have to pay for the labour cost, but you need to know what you're doing. While laying the slab can usually be completed in a few hours, there's a lot more involved that could take the best part of a week.

 

Laying a concrete slab yourself involves the following steps:

1. Check your safety equipment

As well as buying concrete and tools to install it, you also need to have appropriate safety gear. This means covering your skin completely and wearing eye protection, a face mask, gloves and sturdy footwear.

2. Make the frame

Measure the area where your slab will go and lay timbers around the perimeter. Nail these together to provide shuttering for the concrete, up to the height where the surface of your concrete will be.

3. Prepare the base

Use a shovel or turf cutter to make the ground perfectly flat for your slab. You may choose to add a dust or gravel bed for drainage.

4. Mix and pour the concrete

Follow the instructions on the concrete packaging to mix it correctly in a cement mixer or wheelbarrow. Spray water onto the base and transfer concrete using a trowel or shovel until the frame is filled.

5. Remove the frame and water

Leave the concrete to harden for 24 hours, then remove the wooden frame. Keep the surface from drying out by spraying it with water twice a day for the next week.

 

Read more: How to lay a concrete slab

 

Getting quotes from concreters

While you may be able to lay a slab yourself, leaving the task to a concreting company makes it a lot easier and guarantees professional results. When you contact local concreters for quotes, give them as much detail about your property as you can before they come out and inspect it in person.

When you've received your quotes from concreters, you can make a more informed decision than you could by judging from those "from $40/m2" ads you see online.

*Costs and prices in this article are indicative and should only be used as a guide. They also vary locally and are subject to market forces.