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Mixed concrete in a black wheelbarrow

Overview

Whether you’re setting a post, laying a concrete slab, or creating a pathway, using the right type of concrete is key to a strong and durable result. With different concrete mixes available, it’s important to choose the right one for your project. Here’s everything you need to know about selecting and mixing concrete correctly. 

Safety tip: Always wear the appropriate safety equipment (safety glasses, gloves, ear muffs and a mask, for example) and always follow the instructions for the product or equipment. 

Tools and materials

Steps

1Choosing the right type of concrete

General-purpose concrete

For most D.I.Y. projects jobs, general-purpose concrete is the best option. It’s versatile and works well for a range of applications, including setting posts and stumps, laying small slabs, and creating pathways. If you’re unsure which concrete to use, this mix is a reliable all-rounder.

A person is sitting with a bag of Bastion concrete mix.

Rapid set concrete

If you need your project to set quickly, rapid set concrete is a great choice. This mix is ideal for setting fence posts, installing letterboxes, and other non-structural applications where you need the concrete to firm up fast. Since it sets quickly, you’ll have less time to work with it, so it’s important to plan ahead and move quickly once you start mixing. 

Rapid strength concrete is ideal for setting fence posts, installing letterboxes

High-strength concrete

For projects that require extra durability, high-strength concrete is the best option. Available in both standard and rapid set concrete mixes, this type of concrete is perfect for driveways, paths, small footings, and slabs. If you need more working time, avoid using the rapid set version, as the standard setting mix will give you more time to shape and finish your project before it starts to harden.

High strength concrete for projects that require extra durability

2Pour the dry mix

Start by pouring the dry concrete mix into your wheelbarrow. For each 20kg bag, you’ll typically need about 2.5 litres of water, but it’s always best to check the instructions on the packaging, as the exact amount may vary slightly.

Pour the dry concrete mix in a black wheelbarrow

3Add water gradually

Create a small well in the centre of your dry mix and pour in about two-thirds of the required water. Using your shovel or mixing hoe, begin folding the dry mix into the water, working from the edges into the centre. This method ensures the concrete combines evenly and prevents dry pockets from forming.

Add water gradually to the dry concrete mix

4Adjust the consistency

Continue adding small amounts of water as needed until the mix has a thick, smooth, and workable consistency. A good guide is to make sure the concrete holds its shape when scooped without crumbling or becoming too runny. If the mixture is too dry, add a little more water, but do so gradually to avoid making it overly wet.

Once your concrete is mixed, it’s ready to use. Whether you’re filling a post hole or laying a concrete slab, work efficiently to ensure the concrete doesn’t begin setting before your project is complete. 

Adjust the consistency of mixed concrete in a wheelbarrow with a shovel

5Looking for more D.I.Y. projects using concrete?

Health & Safety

Please make sure you use all equipment appropriately and safely when following the advice in these D.I.Y. videos. You need to be familiar with how to use equipment safely and follow the instructions that came with the equipment. If you are unsure, you may feel it is safest to consult an expert, such as the manufacturer or an expert Bunnings Team Member.

Grave health hazards are linked to asbestos, which may be in homes built up to 1990. Health hazards may result from exposure to lead-based paints in older materials and copper chromium arsenic (CCA) treated timber. For information on the dangers of asbestos, lead-based paint and CCA treated timber and tips for dealing with these materials contact your local council's Environmental Health Officer.