Concrete can be poured by the concreters by a mobile truck or made up on-site using a concrete mixer.

Buying and installing a large concrete slab of pre-made concrete will cost much more than the cost of simply laying down some plywood and then putting some bricks or blocks on top. Concrete can be made up of gravel or sand mixed with water, cement and some other additives which help to make the concrete slab stronger such as wire mesh and metal rods by the concreters.

How much does a concrete slab cost for shed

Before beginning with your slab job, kindly note the cost of concrete slabs the different in type and size. The cost of a concrete floor or the cost of concrete slabs for garden shed is generally charged per square metre. Based on the type of concrete, the concrete slab price per square metre (per m2) are as follows:
  • Plain concrete slab structures: $60- $85 per m2

  • Spray-on concrete slab surface: $50- $75 per m2

  • Reinforced concrete slab surface: $65- $90 per m2

  • Decorative stencilled concrete slab: $100- $150 per m2

  • Exposed aggregate finish concrete slab: $100- $150 per m2

  • Coloured concrete slab: $75- $90 per m2

These prices of slab for a shed are exclusive of any labour charges. That's because most factors behind this include thickness (more thickness means more labour), location of the house and ease of accessing the area. An easily accessible area will mean less cost. The details of the different types and categories for your slab will help you with the quote.

Concrete slab cost per square metre

Concrete slab cost per square metre for your shed can vary depending on the thickness of the slab that you want. If you are going to use a thinner or less dense concrete then it will not cost as much as using a denser concrete.

Concrete slab prices depend on the concrete finishes, thickness of the slab, and more. Concrete slabs cost as follows per square metre based on the location in Australia:
  • Western Australia: $40- $55

  • New South Wales: $35- $50

  • Queensland: $30- $45

  • South Australia: $30- $45

  • Victoria: $25- $40

  • ACT: $20- $35

The cost of concrete slabs are sometimes charged per cubic metre. Similarly, the house slab prices range from $64- $108. The rates don't change frequently, so don't worry about the budget difference due to different rates. The thickness is again important to know the final cost of the slab for a shed. The cost and price of slabs for sheds are subject to change sometimes though. Most people charge an average $45, while most also charge a low price. All the costs depend on the property.

The process to concrete a slab yourself

Follow the following steps to cure a concrete slab for your shed.
  1. Breaking the ground with a pickaxe or shovel.

  2. Putting down mesh to assist in the circulation of cement and help hold it together as well as to provide reinforcement for the slab once it is poured. This is otherwise called concrete slab foundation.

  3. Adding gravel and sand which are mixed with water, Portland cement and other additives from buckets into wheelbarrows then pour this mixture on top of the mesh until the required level is reached. The thickness of the slab depends here. If building this thing for durability, keep the thickness high.

  4. Attaching wooden slats that are laid on top of concrete blocks or bricks, adding some wire mesh for strength and rebar before pouring concretes over top of them using a form made from wood boards connected by stakes that support the mould above ground while allowing concrete to set below.

  5. Once the concrete has been set, removing wooden slats and wire mesh before adding a layer of polyester or similar dense material on top to create a smooth finish for the furniture.

The amount of time needed to complete the process will vary depending on how many people you have available and their skill level. If you work alone then this job may take over one day but if you have 2-3 strong helpers this job can be completed in just 1-2 hours.

The process to have a concrete slab poured by a professional

The cost of concrete pouring services include labour as well. Here's the process:

  • Breaking the ground and adding mesh into the foundations where they want to pour the concrete.

  • Using a truck that has a large mixer on it that will pour down cement, sand, gravel and water in various proportions to make the concrete within approximately an hour depending on how much is required.

  • Smooth out the concrete with a power trowel after it has hardened enough.

How long does concrete take to dry?

The drying process for the concrete slab will depend on the climate. If it is a hot and sunny climate then it may take only 1-2 days to dry but in colder climates, where it is wet and damp then this process will take longer.

Once the concrete has dried, a layer of polyester or similar material is added on top to create a smooth finish for the shed floor before you install your shed onto it.

Adding metal supports or steel mesh underneath where the frame will be placed and bracing them in place using brackets secured with bolts so they are strong enough to support the weight of heavy items.

How thick does a concrete slab need to be for a shed?

This depends on what you are planning to put in your shed. If it is just for storage then a few centimetres will be sufficient, however, if you want to install any machinery or equipment inside your shed, make sure the concrete slab in the sheds is thick enough to support the weight as well as keep it from sinking into the earth. But this will increase the costs. The costs increase if the thickness is high. The costs are low if the thickness is less. You can make it up to 10-15 cm thick as this will support the weight of heavy machinery and equipment easily. The amount of time needed to complete the process will vary depending on how many people you have available and their skill level.

How do I make a concrete slab level?

All you have to do is before you pour any concrete for your home shed project, it is important to level the ground first as a sturdy foundation will make this slab building project easier and quicker at home. If your soil is not level at the site then you can even out the area by piling it up on one side of the foundation until it is perfectly straight and level. Once you have levelled the ground, you can then start pouring concrete into the 8-inch deep trench that has been formed. Check the slab level with a line made out of chalk or a spirit level to ensure that it is straight and level.

How do I waterproof my shed floor?

Once you have poured your concrete slab for your shed project, if you would like to make sure it is completely watertight from the inside of the shed then you can use a waterproof coating to coat the entire surface. This will prevent any moisture from leaking through from the inside, and it will also protect your concrete slab.

This is a great idea if you live in a humid climate as this will prevent moisture from seeping into the concrete which can cause cracks to appear over time or may even lead to mould growing within the cracks. For more information on concrete slabs, take a look at the Australian Government's Your Home guide.