In this post, we will cover how to patch plaster walls. Patch plastering is a process of filling areas of the wall or ceiling with plaster and finishing it to a level that means it’s smooth and blends in with the rest of the wall.
This is suitable to do on all previously plastered walls where the finish has been damaged beyond what you can repair with filler.
MATERIALS & TOOLS REQUIRED
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Materials
Tools
- Bucket
- Paddle mixer
- Plasterers hawk
- Plastering trowel
- Jointing knife
STEP 1: PREPARE THE WALL
There are a couple of steps to prepare the wall for plastering.
Firstly, any loose bits of plaster need to be removed. Use a coarse brush and brush off all the loose, flaky bits from the area you will plaster. If any bits of plaster a wobbly but aren’t quite coming off by brushing, remove them anyway by using something like a scraper to flick them off.
Next, apply your plaster primer. Make sure to follow the manufacturer’s instructions on the back. If using PVA instead, make sure to mix it with water to a ratio of about 1 PVA to 3 water. Apply the PVA mixture to the area you’re plastering the day before and leave it to dry overnight. When you’re ready to plaster, apply another coat of the PVA mixture and let it go tacky before starting to plaster. The times may vary but it will take around 30min – 1 hour on average.
STEP 2: MIX AND APPLY THE PLASTER
When the PVA is tacky enough for plastering, it’s time to mix the plaster. Follow the manufacturer’s instructions for how to do this as they may vary depending on the plaster you bought.
When mixed it should a smooth, soft consistency. Not quite as loose as cake batter but looser than a bread mix. For mixing, an electric paddle is really helpful to remove lumps. However, if you are working with a small area, you can mix the plaster by hand. Make sure that the mixture is smooth but not overmixed.
To apply the plaster, scoop some onto a plastering hawk. Use a trowel to fill the holes as required. For smaller areas, you can use a smaller tool such as a jointing knife.
Don’t worry about making the plaster smooth at this stage. Just fill the hole. Make sure that the plaster is not sticking out past the wall and if anything slightly underfill the area.
STEP 3: FINISHING THE WALL
You need to check the manufacturer’s instructions on whether the palster you bought requires two coats. If so, check for waiting time before a second application. Wait that time and apply a second coat in the same way as the first. At this stage, if you are comfortable with your plastering skills, you can fill the hole exactly up to the wall surface and try to blend in the edges so that they wouldn’t be visible when the wall is decorated. Use a soft brush with water to make the plaster more workable.
For beginners, I recommend not filling right up to the wall and instead using jointing compound to finish the area. Jointing compound is a sandable material that is used for finishing plasterboard or mass filling. Read more about the difference between jointing compound and plaster here.
To do this, wait for the plaster to fully dry. Mix the jointing compound as per the instructions on the back and apply it with a jointing knife or even a trowel again. Slightly overfill the area. When dry, sand it smooth to perfectly blend in with the rest of the wall. again check the back of the packet as you may need to apply two coats.
We did neither at this stage because we were planning on applying the joining compound all over the walls to smooth them out later on. This was the final result:
As usual, very informative post. Thank you very much
Thank you!!!