There is one thing you need to get right when plastering and that’s knowing how to mix plaster. This is one fundamental that you NEED to get perfect from the beginning.
It can be the difference between a total success or an absolute failure – the mix is everything. You couldn’t just add random ingredients and measurements to a cake and expect it to come out looking like a lovely Victoria sponge.
There’s a science that you need to follow when mixing plaster and I’m going to show!
You will learn the formula on how to mix plaster and I’ll tell you exactly what happens if you get it wrong. This is a big one! knowing how to get the perfect mix will save you a lot of stress.
First thing’s first you’ll need to know what equipment you’ll need:
- Mixer (preferably electric)
- Bucket Trowel
- 2/ 3 buckets
- Mixing bucket or Gorilla tubs
- Fresh, clean water
- Finish plaster (I’m mixing British Gypsum multi finish)
Heres is a video that shows you everything you need to know if you want to skip reading:
How much water do I need?
According to British Gypsum, you should mix 11.5 litres of water to one bag of multi-finish plaster. Now without sounding too self-explanatory, if we follow this advice we should get the perfect amount of water to plaster ratio. Sounds simple right?
Well, there is one big problem; this is absolute rubbish! It’s way to little water and your mix ends up too thick. 12.5 litres is the amount I go by (possibly 12.5 – 13 depending on how you like your mix).
The black standard buckets (the £1 ones from B&Q) can hold a maximum limit of 12 litres. However, this is the measurement when it’s full to the brim so we’ll take a bit off.
So the theory us plasters go through is roughly one full bucket of water to one bag of plaster! Easy. A better solution would be to get a big mixing bucket where the measurements are engraved on the side. This is what I recommend if you’re new to plastering.
You can see the exact amount to use and there isn’t any guesswork. This way you can see what the perfect mix looks like and eventually it won’t be important because you will just know how much water to use.
In the meantime, I would use the buckets with the measurements engraved on the side.
You can buy these from Amazon – a good one is the Draper 12100 Plasterers Mixing Bucket. It’s strong, easy to mix in and has the measurements clearly labelled on the inside of the bucket. Simply pour 12.5 litres of water and following these simple guidelines.
(PSSS.. I know this is a lot of information to take in but you can save this article. This way you’ll have all the measurements and equipment you need ready for when your mixing.)
How to mix plaster
You have your water in the bucket which is accommodating for 1 whole bag of multi-finish plaster. Here is the best way to mix your plaster.