Plastering is a job lots of people tend to leave to the experts, but it is a practical skill to have up your sleeve if you enjoy DIY. You may need to plaster a wall from scratch, or smooth over some minor cosmetic repairs in the ceiling. In this article, we will share a step-by-step beginner’s guide to plastering a wall, alongside some handy tips along the way.
The tools you’ll need for your wall plastering project:
Step 1: Prepare the area for wall plastering
Ensure the area is clear of furniture and other objects that may get in the way. Use protective sheeting or old blankets to cover up larger items that can’t be moved.
Step 2: Get the wall ready
Ensure the wall is clean and free from dust and debris.
Fix the angle beads to the plasterboard edges – using a staple gun works well. Angle beads give the best finish to edges, plus provide a great guide to the correct thickness of the plaster you need to apply.
Apply some scrim tape to your plaster board or any cracks if on an existing wall. All buildings and walls move due to expansion and contraction, and the potential for cracking is always there, but with this self adhesive scrim tape you really do minimise the risk. Just stick to the top of your board and roll and stick as you go covering the joint. Once at the bottom you can either use the toe (front edge) of your trowel to cut the mesh with a ripping motion or a Stanley knife.
Step 3: Glue it out
Mix some PVA glue at a ratio of 4:1 – that’s 4 parts water to 1 part PVA glue. This is more applicable if you’re plastering on to old plasterboard or skimming over old walls. However I still use this as an aid to my plastering even on new plasterboard. Mix the PVA glue mix and allow to dry (preferably overnight if you have the time). Once it has dried you then apply a second coat of PVA mix. When this has become tacky and nearly dry, you then start to mix your plaster – this is the glue coat which helps the plaster to bond with the wall.
Step 4: Mixing your plaster
Add the powder to the water in stages to avoid getting lumpy bits at the bottom of your bucket.
For a bag of plaster (Thistle Multi finish) you need roughly 12.5 to 13 liters of water – try different amounts between this gauge to find a mix that is neither too runny or too thick. Ideally your plaster should be creamy and firm enough so that when you remove your paddle mixer, the sides where your mixer was should hold firm and not collapse in on itself. Your second coat mix should be slightly wetter than the first. It will still hold firm but slump in a little.
Aim to mix the plaster in 3 stages. Begin with your clean water, never dirty or even slightly dirty water. Also, make sure you wear a mask to protect yourself from dust from the plaster.
Add enough plaster powder till it sits on top of the water. Use your paddle mixer on a slow setting to get it all nicely mixed together. Use your bucket trowel to clean the powder and mix back into the bucket.
Add your second amount of plaster again till it sits on top of the water. Then mix with the paddle and use your bucket trowel as before. Your plaster should be now getting close to correct consistency.
For the final third, you will be able to gauge how much powder to add to get the right mix for you. Just always remember to move your paddle up and down and around the side of the bucket and clean the side with your bucket trowel.
Now, onto the plastering!
My top tip at this stage: clean all the materials you’ve just used.
Step 5: Time for the first coat
If you are right handed, then start plastering from the top left of your wall – and vice versa if you’re left handed.
A lot will depend on the size of your wall, especially height. Because this wall is not very high, I knew I could plaster the top first, meaning that I could come back to the beginning and plaster from the floor to meet the top. However, if the wall had been taller and longer, I would have broken it down into individual areas.
So, the first thing is to wet your trowel and hawk with clean water. I always have a small bucket and brush with fresh water during the first and second coats. Then get a little amount of plaster on your Hawk and smear it around with your trowel. This will stop your plaster falling on the floor when you start. Next, get a dollop of plaster with your bucket trowel and put into the middle of your hawk. The hardest part is getting it on your trowel from your hawk. Let me explain:
Hawk in your left hand, trowel right hand – opposite if you’re left handed.
Tilt your hawk slightly inwards and push your trowel into the top of the plaster at the halfway point and push through and out the back. Increase the tilt inwards as you push through so as not to push it straight on to the floor. It’s worth practicing with a little plaster if you can spare any.
You then apply the plaster with your trowel at about 15° – 20° to the wall. Steadily glide your trowel and plaster across the wall narrowing the angle as you go till it’s almost flat, applying even pressure throughout. Do not worry at this stage if it doesn’t look pretty, as that will come later. Ensure you are filling all the gaps at the angle of the wall and ceiling. Ideally you need to be laying approximately 1-2mm of plaster.
Continue this process until you have completely covered the top third of your wall.
For the bottom section, load your trowel and stopping just short of the floor, place your trowel against the wall. Using the same technique and angles as before, glide your trowel up the wall using the angle bead as your guide. Always apply even pressure and this will help you keep it flat. If you hear a scraping noise you are pressing too hard. If you end up with a big dollop on the wall then not enough pressure.
As you become more confident, you can apply more plaster and be able to fill in from the bottom to the top third you have done already. However, if you need to do a middle section then do that first with this same method, finishing from the bottom to the middle. The reason we do this is so that each section blends in with each other.
Complete this whole process across the wall. When you are plastering up the wall, move in a sweeping arc like motion as if you were creating a rainbow, but keep the arc short. Once again this helps to blend all the new plaster into the plaster already laid on the wall.
And the first coat is complete! Clean the tools with clean water.
Mytop tip at this stage: For your first attempt don’t load too much plaster onto your hawk.
Step 6: Get in line
It is normal if there are some lines and uneven patches at this stage. However, you don’t want the wall to set the way it is with lots of lines in it. As it starts to firm after approximately 15 minutes, you can start to get rid of the lumps and lines by troweling over the whole area, trying to get it as flat as you can.
You also need to pay attention to the corners, top and bottom of the wall, using the edge of your trowel to cut away any excess plaster. Using a small brush is very useful for the angles.
Step 7: Time for the second coat
The second coat should be applied once the first coat has become tacky, like putty. You can push into it and leave a print but you won’t pull the plaster off the wall. If it pulls from the wall and or comes off a little bit on your finger, then leave it a bit longer to firm up.
Mix your second coat as you did the first. However, you should not need as much as the first coat as the first is your base coat, the second is where the magic happens. The second coat should go on much smoother and fills in all the voids and imperfections. I would also make this slightly runnier than the first.
Then you will apply the second coat exactly the same way as the first. This time we are aiming for 1mm covering of plaster. Working from the top edge, pull the plaster down the wall to help fill in the voids.
Once the top is completed then start at the bottom and do the same as previous. Nice smooth long strokes up the wall to meet the previously laid plaster forming an arc at the end.
Try fill as many holes as possible, again don’t get too tied in with this as the wall will be setting. Keep applying good even pressure throughout the process. This will push the plaster into all the gaps and help keep it flat and even.
Step 8: Fill any holes
As you pass over each part of the wall with your trowel check for holes. With good firm pressure, start to fill in any holes as you did previously. Just the pressure alone should fill in the holes but if needed, use the excess that is on your trowel.
Step 9: Smooth things over
At this stage, we have a wall that is hole free – but there may still be lines to attend to.
Once the plaster is firm enough to flatten the ridges without making any more lines, then you are ready to go. If you do create more lines then your plaster is still too wet and you’ll need to wait a little longer for it to dry. Once the wall is firm enough, trowel out those lines.
My top tip at this stage: Have a cup of tea and just keep checking the wall.
Step 10: Add a splash of water
Using clean water, with both a bucket and brush or spray bottle, we need to smooth our flat plaster with water. Wet the brush and apply along the wall, then trowel across with a good even pressure. If the water runs down, trowel it out.
Any creamy plaster left on your trowel is what’s called the “Fat” – this is what gives the wall its smooth finish. Keep it on the wall to fill the small imperfections. Work the corners and the angles; they will make your job look great with clean cut angles and beads.
Step 11: Wall plastering – the final trowelling
Final steps – give the wall another trowelling. Grab a damp rag to clean the trowel, then trowel out your wall once again. Using a dry trowel will give a shine to your wall, but don’t overdo it as the paint won’t stick afterwards. There should be nothing coming off the wall now at this stage.
A top tip for the whole process: constantly check your wall by touching it. You can’t do much when your plaster is soft apart from get it on the wall and move it around. As your plaster is starting to firm up, that’s when you can start to fill in the holes and get rid of those lines, then it will start to look like a plastered wall. And voilà! Our beginner’s guide to plastering a wall.
Written by one of our expert Manodvisors
I am D from D&L Plastering. I have be plastering 8 years and came to the plastering game a little later than most. So if I can do it then so can you! I work in all areas of plastering -plastering, rendering, dry wall construction. Additionally, I am fully trained in venetian plaster finishes.