How to lay a concrete slab

Learn how you can lay a concrete slab with this step by step guide.

It’s important to get the basics right so you can enjoy your slab all year round. If you want to lay a small slab, path or footing, Easy Mix Concrete is the ideal concrete as it leaves a smooth finish. For larger structural jobs such as footings and foundations, Easy Mix Super Strength Concrete is a great choice.

Below is our guide for laying a small lab and can be used for small footpaths as well.

What you will need

  • Easy Mix Concrete
  • Potable (clean) water
  • Shovel and rake
  • Spirit level
  • String line
  • Tape measure
  • Timber (for boxing)
  • Hammer, saw and nails
  • Scoreboard and trowel/edging tool

Calculate the materials required

Mark out the size of the area and calculate the square metres so you know how many bags of Easy Mix Concrete are required.

Square metres = length x width

  • 1x 20kg Bag = 0.01m³
  • 100x 20kg Bags = 1.0m³

Calculate how much water you will need to mix with the concrete.

Site Preparation

Dig the site to the required depth (most paths are at least 75mm deep).

Make sure to allow space around the slab/path dimensions for the timber formwork to sit.

1. Formwork

Use lengths of timber to box the area of the slab or path.

The top of the boxing will act as the level of the top of the concrete.

You can also place welded reinforcing mesh within the formwork for extra strength.

Ensure you allow for water run-off.

2. Prepare To Pour

Just before pouring your concrete, thoroughly moisten the area with a hose. This slows down moisture loss during curing and assists in making the concrete stronger.

3. Mix The Concrete

Pour the required volume of premix concrete into a wheelbarrow, mixer or onto a clean surface.  Create a well in the concrete for the water to be poured into.

Add water gradually and mix thoroughly to a stiff consistency. Do not add water after the concrete has been mixed, as this will reduce the final strength of the concrete.

NoteExcess water can ruin good concrete, use caution when adding water to your mix.

Shovel or pour the concrete into the formwork until it fills to the edges. Use a shovel to spread the concrete and tamp it down until it is relatively level.

4. Screeding

Using a straight-edge board across the top of the formwork, screed the concrete to the desired level.

Work the screed board across the top of the concrete, from one end to the other in a sawing motion to bring it to the desired level.

Fill any holes and screed again, removing excess concrete if necessary.

Leave the concrete to set for approximately 1 hour to let the water come to the surface before trowelling to your desired finish.

5. Finishing

A steel float should be used to achieve a smooth even finish. To finish the edges, an edging tool should be used to achieve the best results.

For a non-slip finish (or if tiling over), use a wooden float in a circular motion across the slab.

6. Curing

To help the concrete cure at full strength, cover with a used damp hessian cloth and keep it moist for several days.

Products you may need

Downloads

Video tutorial

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