Gather all of your tools and materials together and put on some old clothes before you start to apply a skim coat, as it can get a little messy.
Follow these steps to skim coat a wall successfully:
Step 1
As plastering can make the room you’re working in dirty, the first step is to cover everything with dust sheets and plastic sheeting.
Move everything away from the walls you’ll be skimming into the centre of the room and cover it with dust sheets for protection.
For floors with carpets, it’s a good idea to put plastic sheeting down and use masking tape to stick it to the skirting boards.
Remove the plug socket covers and light switch plates from the wall with a screwdriver and cover them so they don’t get plaster on them.
Step 2
So that the new skim coat can adhere properly, you should make the wall you’re working on as smooth as it can be.
Remove any nails, screws, or picture hangings, and use jointing compound to fill any cracks or holes in the wall.
If your wall has loose plaster, pull it off and fill the holes, if possible.
Walls with wallpaper on need to be stripped, and walls with a paint coat already on should be roughened with sandpaper.
Lastly, use a damp cloth to remove any grease marks on the wall and give it all a brush down with a soft bristled brush to remove any dust from the surface.
Step 3
Next, apply a primer to the wall so that the new layer of skim coat will adhere.
You can buy a ready-mixed primer, or apply your own water-based primer made of one part PVA glue and four parts water.
Apply the primer to the wall with a paint roller, covering every surface. For areas that are indented, or around the edges of the room, use the paintbrush.
Step 4
It’s time to mix your plaster for the skim coat.
Plaster for skim coats can dry quickly, as the layers are so thin. When you mix it, be ready to apply it to the wall within 30 minutes or less.
Add the plaster and water to a mixing bucket, water first then the plaster, and whip it together with the power mixer and paddle attachment.
Run the attachment around the side of the bucket and down to the bottom to make sure all of the plastering powder is incorporated into the mix.
It should not be too hard or too runny, instead it should have some fluidity and a creamy texture to allow you to skim the wall without it dripping.
You can always add more water or powder to the mix to correct bad consistency.
Step 5
As you’re plastering a large area, you can add the plaster onto a large spot board on the floor so you can easily access it.
If you prefer to have your materials closer to hand, then you can trowel some of the plaster onto a plastering hawk and top it up as needed.
The technique used is similar to plastering a ceiling or wall.
Start at the bottom corner of one wall and push the trowel of plaster across the wall, dragging it over the surface vertically with an even amount of pressure.
Once your trowel is empty of plaster and you’ve smeared it onto the wall, take some more and repeat.
Make sure to overlap the areas you’re plastering so there is an even depth of a few millimetres.
It’s important that you get this first coat on quickly, and don’t worry about it not being completely smooth as you will be adding further coats.
Step 6
Before the first coat has fully dried, start on the second coat.
It helps to have someone who can mix your second batch of plaster so it’s ready for you to start using straight away.
You can now apply the plaster in a different direction to make sure there’s adequate coverage and the plaster is being applied evenly.
If you’ve left trowel marks in the first coat, now is the time to smooth over them carefully.
Have a bucket of clean water ready to wash your trowel every so often so it is completely smooth and free of any hardened plaster.
If you notice the plaster drying in certain sections, mist it lightly with the spray bottle of water to keep it damp while you work on a smooth finish.
You can use the trowel or even a paintbrush for the edges of the room, but a taping knife will deliver a much neater finish to these parts.

Step 7
Once you’re happy with the wall surface, leave it to dry for at least 24 hours.
If you notice that there are still some raised areas, use sandpaper to gently rub them down to the level of the other plaster.
Pro tip: work in a circular motion to get even coverage instead of rubbing the sandpaper horizontally or vertically over a particular section.
That’s it! You should now have a perfectly skimmed wall to be proud of.
All that’s left to do is clean up and replace the furniture in the room.
Plaster can take a few days to dry out completely, so it’s best to leave it for at least one or two weeks before you start to paint the plaster or apply wallpaper.
Turn the radiators in the room off as heat can cause the plaster to crack.