How to plaster a wall
Plastering is a skill best left to the experts. However, if you feel you are more than handy when it comes to practical D.I.Y jobs and you know how to work in a slow, methodical and neat fashion, then this step-by-step guide to plastering will ease you through the job, and hopefully make it look like a professional did it.
Firstly, get the right tools and materials for the job.
- Dust sheets and dust masks
- Screen tape to cover the joints
- Plasterer’s trowel and hawk
- Deviling float
- Plasterer’s float
- Cutting knife
- P.V.A glue, emulsion roller and tray
- Corner beading
- Clout nails
- Corner beading
- Board finish plaster
- 2 buckets (one for plaster and one for water)
- Stirring rod or mixer
- Cloth/rags and spray gun for misting
Your step-to-step guide to plastering a wall.
Follow this step-by-step guide to get the best finish. It is important to be thorough, methodical and patient. A rushed job will most likely be a bad job.
Make sure the area you want to plaster is free from dust and loose debris. Lay down a dustsheet to protect your floors and collect any later debris or plaster spillage. This is very important if you are plastering an older existing wall. Cover any holes and cracks you may find, you can use screen tape for this. If you are plastering over newly erected plaster-boards, use screen tape to mask all the joints between the boards.
Top Tip – Clean as you go along – it may sound over the top but it’s vital to have clean buckets, tools and equipment to ensure your plaster doesn’t go off and you get a better finish that lasts.
When plastering a room, try not to do two walls that are touching each other as you risk damaging one wall while plastering the other.
Keep it cool in the room you are plastering – radiators should be turned off or the plaster will dry out too quickly, making it difficult to apply and crack.
2: Apply P.V.A to walls
Use P.V.A for bonding, this creates the best result and ensures that the layer of plaster you are applying later, will dry out evenly. Dilute the P.V.A in a 1:4 ratio – one part P.V.A and four parts water. Roller or brush the P.V.A mixture onto the wall, ensure the entire wall is covered. As soon as the P.V.A glue has become a bit sticky to the touch, the first layer of plaster can be applied. For the best result, always follow the instructions given by the manufacturer of the glue.
Top Tip – You could add a handful of sand to the P.V.A mixture to give it a rougher texture and better adhesion.
3: Mix plaster
Wear a dust mask before you open up the bags of plaster. Mix the plaster into cold water, whisk quickly, but carefully, until it has the consistency of thick custard. There should be no lumps. Always mix the plaster into the water and not the other way around.
Top Tip – Dry plaster is a nightmare to remove from your tools and can cause drags in the plaster finish.
Always use clean water, again to avoid contaminating your plaster and make it go off or set too quick. Add just enough plaster first to make a heap on the top of the water and mix it so that it’s lump free, then slowly add the plaster to get the correct consistency either with a wooden stick or mixer drill.
4: Apply plaster
Using the hawk board, trowel and float, you’re ready to apply your first coat of plaster. Practice the movement on a separate plasterboard sheet before you start the actual job, just to make sure you are getting the technique right.
Load plaster on the hawk board using the trowel. Use the float to push the plaster from the hawk onto the walls. Do this with the float close to the wall, spreading the plaster firmly upwards and flattening the float at the end of each sweep. Start from the bottom left-hand corner and upwards, filling a section from bottom to top before you move on to the next section. Use small amounts of plaster each time in combination with lots of pressure on the float, as this is the best way to ensure a smooth look and avoids excess plaster falling off the wall. Repeat until the entire wall is covered.
5: Skim and Smooth
After the first coat of plaster has been applied, wait approximately 20 minutes to let the plaster dry slightly. Smooth over any lumps and bumps with the trowel. You also need to smooth out all the corners and ends such as the bottom and top of the wall. These can be difficult areas to plaster correctly. Use a wet brush to even the edges out.
Top Tip – A good plaster finish can be achieved with a combination of confident firm pressure and the correct angle of your trowel.
Don’t try and get your surface perfect in the first coat – it takes too much time and the plaster may dry too soon – imperfections can be ironed out in later stages.
This is optional but some people prefer to scrape the surface before adding a second coat. This is so that the second coat can adhere properly. The easiest way to do this is by using a tool called a devilling float, (it’s a wooden float with nails in it). You can also scratch the surface using an old kitchen fork. If you choose to use neither option, then just make sure the first coat on the wall is still wet before applying the second layer of plaster.
7: Apply plaster
After devilling or scratching the first level of plaster you can apply a second and final coat. This should be a thinner consistency than the first, so make sure to dilute the plaster mixture with some more water. Only plaster a thin 2 mm layer. Then leave the plaster to dry slightly.
8: Finishing touches
After the plaster has dried slightly you need to polish up your work. You do this by adding water to the surface using a spray gun.
Top Tip – When wetting your walls use a fine mist spray gun to avoid having to keep reaching down to re-wet your brush.
Once the water starts running down the wall, you know you’ve controlled the suction.
Spray the edges of the plaster and the run the trowel over it to smooth out the surface. Use inward strokes when doing this. You can also use a wet brush for the job, especially around the tricky edges. Finish by running a clean float over the entire surface to flatten out any lumps and bumps.
After the plaster has dried out completely, you can use some sanding paper to remove any excess plaster you may find.
Top Tip – As the plaster sets it will darken in colour, which means it’s time for the final trowel.
Don’t over polish the plaster on the final dry trowel stage – it should be even and slightly polished, but feel like eggshell – any smoother, it makes paint and wallpaper a nightmare to stick to.
9: Painting and Wallpapering
Once the plaster is completely dry, it’s ready to be painted or wallpapered. Before you paint over the new plaster you should use an undercoat in order to prime the surface. The same is the case if you’re hanging wallpaper, although in this case you would use wallpaper adhesive. Apply one or two coats of adhesive to prime and seal the surface.