How much does it cost to have a concrete slab poured?

Please note that the price information in this article was based on data from 2018 and may now be outdated.

The price of a concrete slab pouring is $60 per square metre on average. This is an average that has been calculated based on the quotes from Service Seeking concreters and the projects they have sent their quotes for in 2017 and 2018. This is the price of the concreting work done, but it doesn’t include the materials.

There are other factors that will influence the price of your concreting. They are:

• Accessibility of the terrain
• Size of your concrete slab
• Type of your concrete slab
• The function of your concrete slab
• Different finishing for your concrete slab

The first item on this list is very self-explanatory. If your concreters have to pour a concrete slab under difficult conditions, they will definitely charge you more for that type of work. Hard-to-access areas mean that they need to drag the equipment to places that require them to carry heavy weight repeatedly.

It can also mean that some of their work needs to be done manually because the equipment just cannot reach critical points. In that way, you can expect to pay a higher price of concrete per square metre.

How Much Is Concrete per Square Metre?

You can expect to pay anything from $50 to $90, depending on the type of concrete you are using. Note that the prices can go up to $150 if you are opting for different types of pencilled, stamped or polished concrete.

The most economical version is the spraycrete or the spray-on concrete. This is usually used for resurfacing. Most of the surfaces will be done with basic concrete. That is in the ballpark of $60 – $85 per m2.

The most expensive and the most resilient is reinforced cement concrete or RCC concrete. This type includes rebars and steel rods, so it is used for building concrete slabs that will have to sustain considerable pressure.

How Many Types of Concrete Slabs Are Out There?

Generally speaking, there are two main types of concrete slabs:

• Ground concrete slabs
• Suspended concrete slabs

Ground concrete slabs are those that are poured directly on the ground. The suspended concrete slabs are those that need some sort of reinforcement. They have

There are many more subtypes of concrete slabs, even mentioning the number 16, but the truth is, there is no official classification from the Concrete Institute of Australia. However, if you talk to the concreters who mostly do their work in residential areas, they will tell you that the suspended concrete slabs come in different forms.

What Is a Suspended Slab?

This is an umbrella term for all concrete slabs that don’t touch the ground directly. Some of them have subfloors and footing. These are the types of suspended slabs that you are most likely to encounter. They include:

• Raft slabs, such as stiffened raft slabs and waffle raft slabs
• Piered slabs

Piered slabs are usually used in terrains that are unstable. If the ground is unstable for any reason or the slabs have to be positioned on a surface that is far from being flat, these slabs need piers placed in the ground so that they can rely on them for support.

Raft slabs are the types of slabs that need some sort of subfloors. Those subfloors can be made out of concrete beams and rebar placed in the ground, but more commonly into sand bedding. Additionally, the subfloors can be made out of blocks.

• Stiffened raft slabs are those that are laid on the grid of concrete beams that are poured into channels.
• Waffle raft slabs have a subfloor made out of polystyrene blocks.

Photo from nationalpolystyrene.com.au

Other types of suspended concrete slabs simply don’t go to the floor at all. They are used for making storey floors in buildings and similar constructions. They can be one-way slabs that are suspended on two sides or two-way slabs that are suspended on all four sides.

What Is Your Concrete Slab For?

This is a question about the function of your concrete slab. Do you need it for house foundations? Shed? A driveway? A garage? This will influence the type and thickness of your concrete slab. Consequently, it will mean a great deal when it comes to forming the price of your concrete slab.

We already said that the price of your concreting work is usually formed based on the area that needs to be covered. However, if your slab is thicker, it means more material. More material costs more.

Therefore, you should consider the purpose of your slab when negotiating the price with concreters.

How Thick Should a Concrete Slab Be for a House?

The concrete slab for your house should be 10 cm to 50 cm thick. These are the measurements for the plain, ground concrete slab. They don’t include the rest of your foundations.

If you need a waffle grid or stiffened raft slabs, they will need some more subflooring, which can also involve concrete, but also other materials like blocks, sand, gravel and others.

Note that you should always plan your foundations and flooring in accordance with Australian laws and guidelines.

How Thick Should a Concrete Slab Be for a Shed?

In most cases, the thickness of a 7.5 cm to 10 cm concrete slab is enough for your shed. This is the case if there are no extremely heavy items in your shed. The concrete needs to sustain its own weight and the weight of everything you place on it.

How Thick Should a Concrete Slab Be for a Garage?

It is advisable to have a concrete slab that is 15 cm thick for your garage floor. Cars are not light objects, and if you are about to have an SUV parked there, make sure you have a floor thick enough to sustain it.

Concrete used for residential projects usually can sustain up to 500 kg/m2 of imposed load. So, if you take into account that a large family car or an SUV can weigh anywhere from 1,500 to 2,500 kg empty, you see that you need a concrete slab that is a bit on the thicker side.

All these factors need to be considered when making a concrete slab. The price will depend on the material and on the labour costs. While you can save up on material, there is no good reason why you shouldn’t save a bit on labour, as well. Don’t overpay your concreting. Ask for quotes from professional concreters in Australia.