Depending on how much cement you need, you can either mix it by hand or use a cement mixer. We explain both methods below, so you can learn how to mix concrete.
Difficulty rating: Medium
These tasks may be tricky so will suit you if you’re experienced in DIY, or simply love a challenge.
Before you get started on any of our ‘how to’ guides, please take a moment to read through our DIY safety tips.
What you’ll need:
Method 1: Mixing cement by hand
If you’re mixing cement by hand, use a large mixing board on the ground.
Clean off the mixing board to remove any old debris, then wet it.
Carefully measure out about half the sand and gravel you’re going to mix – and place it on the mixing board to form a cone shape.
Use a shovel to form a crater in the middle of the pile, then measure out all the cement required and add this to the crater.
Measure out the remainder of the ballast (or sand and gravel) you need and add this to the top, forming a cone shape.
Use the shovel to mix all the ingredients together. Work around the heap, turning over each part three or four times until the mixture is evenly coloured.
Reform a cone shape and make a crater in the top of the heap – add some water to the crater.
Move the mixture into the central crater and turn it over to distribute the water throughout the mixture.
As all the water becomes absorbed, reform the heap and add more water to the crater. Keep turning the heap until the whole mixture is wet. Don’t add too much water – you can always add more if the mixture isn’t wet enough.
As all the dry material becomes wet, flatten out the heap and use a shovel to ‘chop’ into the top, moving around the heap as you do so, to evenly mix in the water. A mix which has the right amount of water is smooth and consistent, not over-wet and runny nor dry and crumbly. As a guide, watch the ridges as the top of the heap is ‘chopped’. If the depressions between the chops fill with cement slurry, the mixture is okay. If it looks like a watery slurry, or the ridges don’t stand up, the mix is too wet. If the depressions remain dry, the mix is too dry.
Method 2: Using a cement mixer
Alternatively, if you’ve decided to use a cement mixer it’s important to make sure the amount of cement you plan to mix in one go is appropriate for the size of mixer. If the volume is too small, it won’t mix correctly. And too large a volume could overload the machine.
Make sure the cement mixer is stable and positioned on firm and level ground.
Start the mixer running with the drum pointing towards the sky at a 45 degree angle. Once you start loading the ingredients, the mixer should be kept running until it has been emptied – if you stop a mixer with a load in the drum, it could prove hard to restart.
Measure about half the sand and half the gravel required and pour this into the drum. Keep your hands and tools out of the rotating drum – pour the ingredients in from above.
Add a small amount of water and allow this to mix into the sand and gravel for a minute or two.
Measure and add all the required cement.
Measure and add the remaining amount of sand and gravel and allow it all to mix together for a minute or two.
Gradually add some more water and give it a chance to mix in before adding more – watch the consistency of the mix. A good mix is smooth and flowing, not wet and runny or dry and crumbly.
When the mixture is the correct consistency, move a wheelbarrow into position and tip the drum to empty out the cement. Do this with two people – one to tip the drum and one to steady the wheelbarrow.
When the job has been completed, or you want to take a break from mixing for half an hour or more, the cement mixer should be cleaned down. To clean the inside of the drum put sand, gravel and water in and run the mixer for five minutes. After this, tip the load out and then wash down the inside of the drum with it pointed towards the ground. Switch off the mixer and clean any other areas using a stiff brush.