A Guide to Mortar Mix Ratios & Cement Mixing
We have put together this ultimate guide to mortar mix ratios and cement mixing to help you understand the process and measurements, so you can put it into practice for your next project.
Before we delve into the more in-depth knowledge of mixing, it is important to properly understand the basics.
Cement is a grey substance that is used as a binder in construction. If you mix cement with sand and water, it will form mortar. Or if you mix gravel and water it will form concrete.
Mortar is made out of sand and water, some construction workers add lime into the mix too. It is used in thin layers during bricklaying so that the bricks stay stuck together and in place. If too much mortar is placed on the bricks it can cause cracking. The standard thickness of mortar in brickwork is 1mm or 1cm.
Concrete is made of cement mixed with gravel and water. A fun fact about concrete is that it is the second most used material in the world, and the first is water. It is an extremely strong material and is often nicknamed ‘artificial rock’.
Mortar could be compared to glue, whereas concrete is used for the foundations. Getting the mix ratio for these two materials is crucial to get the best result. If too much water or not enough water is used, it can have negative consequences.
Mortar and Cement Mixing
Mixing is a great skill to have, and it is easy to pick up once you know how to mix and have a bit of practice. The first step is to get hold of the right equipment, which includes:
- Mixing area: wheelbarrow, plastic tub, mixing board
Mixing can be quite a dangerous process, as there are dangers to using the chemicals. Cement is a dried up piece of rock with a high pH balance, so breathing in this powder and touching it brings about health risks. So, before starting mixing you should get the correct safety equipment, this includes:
- A mask or mouth protector
If you do not get the ratio correct, then it can have negative consequences for your construction. For example, if you add too much water to the mortar mix, then it will not properly glue the bricks together. Then, over time the mortar will crumble and not withstand bad weather conditions.
On the other hand, if you add too much mortar mix, then the mortar might easily crack or shrink. Cracking can cause many problems for you in the long run.
The best consistency of mortar for bricklaying is for it to be wet and thin. Only a small amount is used when layering. However, some jobs like fitting a roof may require it to be slightly thicker.
The standard ratio for average mortar mix is 3:1 or 4:1 for bricklaying. If you are using a pointing mix, then you should have a ratio of 1:4 or 1:5 mortar to sand.
As for concrete, it depends on the strength you need it to be at. Usually, it is good practice to mix concrete at 1:2 mix to materials.
There are additives you can mix with mortar mix to get better results, these are:
- Colourants: this additive can be used so that the colour of the mortar matches closely with the bricks you are working with.
- Frost Proofer: this can be used if you are working in low temperatures. However, this can not fully be relied on and should only be used if necessary.
- Accelerator: this speeds up the process at which mortar dries. But, it does weaken the result, so it should only be used in emergencies.
Other Things To Consider
- Temperature: you should never mix or layer mortar if the temperature is 5 degrees or under. This can result in frost forming in the substance, which can lead to weak mortar.
- Trial and error: it is unlikely that you will get the perfect mix the first time around. It is all about trial and error, so you can figure out what works and what doesn’t.
- Mixing by hand vs equipment: You will get significantly better results if you mix mortar in a cement mixer. It is very unlikely you will get the consistency you need if you mix by hand. However, if you are just touching up the mortar, then it can be done.