Plastering a wall is the sort of job that most people leave to the professionals, but have you ever thought of re-plastering a wall yourself?
I’ve had a go at plastering small areas of a wall myself and it’s definitely doable with some patience, practice and plenty of research. You may not want to plaster your entire home, but a small area could be just fine to do yourself.
It is totally possible to DIY this job if you’re up for it. Here are a few tips that might just help if that is what you want to do.
Table of Contents
Proper Preparation
Plastering is like any other job in that you will get the best results if you prepare properly.
You need to start by protecting your flooring. Using something such as Florprotec Carpet Cover, which you can click here to find out more about, will keep the dust that plastering creates out of your carpets and protect them from any loose debris. Brush the wall with a broom to remove any dust and if there are any cracks or holes cover them with screen tape. If it is a new wall you are plastering, cover all the plasterboard joints with screen tape.
When plastering a wall, it is essential to protect electrical sockets and other fixtures from plaster splatter and debris. Covering them with plastic sheeting or masking tape provides a barrier that prevents damage and makes it easier to clean up after the plastering process is complete. Taking these precautions ensures the safety of electrical components and maintains the functionality of fixtures during and after plastering.
Bond With PVA
Dilute PVA glue to one part PVA and four parts water and then apply it to the entire wall.
Priming a wall with a PVA (Polyvinyl acetate) solution before plastering serves several important purposes:
- Improved adhesion: PVA acts as a bonding agent between the wall surface and the plaster. It helps the plaster adhere more effectively, reducing the chances of it cracking, peeling, or detaching from the wall over time.
- Reduced suction: Unprimed walls can be highly absorbent, which can cause the plaster to dry too quickly and weaken its bond. PVA seals the porous surface of the wall, reducing its suction and allowing the plaster to set more evenly and gradually.
- Enhanced workability: When plaster is applied directly to an unprimed wall, the wall’s porous nature can absorb the moisture from the plaster too rapidly. This can make the plaster stiff and difficult to work with, reducing its workability. PVA helps regulate the absorption of moisture, keeping the plaster workable for a longer period, allowing for smoother application and a better finish.
- Improved finish: Applying PVA before plastering can result in a smoother and more consistent finish. It helps to create a uniform surface by sealing any imperfections, such as small cracks, stains, or irregularities on the wall. This smooth base makes it easier to achieve a professional-looking plastered surface.
It’s worth noting that while PVA priming is commonly used, there may be alternative primers available depending on the specific requirements and conditions of the project.
Prepare Your Plaster
To begin, it’s important to properly mix your plaster. Prior to opening the bags, it is advisable to wear a dust mask for your safety. Using a paddle mixer or plaster mixer, gradually add the plaster into cold water, ensuring not to reverse the order. Vigorously stir the mixture with the mixer to eliminate any lumps, aiming for a final consistency similar to that of thick custard.
Apply First Coat
Put some plaster on a hawk board and use that to push the plaster onto the wall. Spread the plaster upwards as evenly as you can. Work in small sections, starting at the bottom and finish each section before you move onto the next. Use small amounts of plaster and lots of pressure as this will give the smoothest look and help to avoid excess plaster falling from the wall.
Smooth
Leave the plaster to dry for about 20 minutes and then get rid of any lumps and bumps by smoothing it over with a trowel. The corners and edges might need some attention at this time as well, and a wet paintbrush can be useful to help you get these right.
Scrape
You need to apply a second coat of plaster and the easiest way to make sure this adheres to the first is to scrape the first coat. There is a tool specially designed for this job, which is known as a devilling float or plasterer float, or you can grab a fork from the kitchen and do it with that.
Apply The Second Coat
The second and final coat of plaster should be mixed a bit thinner and should not really be any more than 2mm thick. Leave it to dry slightly and then add some water to the surface to make it easier to make it smooth. Finish off by running a clean float over the entire wall to flatten out any lumps and bumps.
Leave it to dry completely and then use sandpaper to get rid of any excess plaster around the edges.
Drying times
The drying time for plaster can vary depending on several factors, including the type of plaster used, environmental conditions and the thickness of the plaster layer. As a general guideline, plaster typically takes about 48 – 96 hours to dry. However, it’s important to note that thicker layers or high humidity levels may prolong the drying process.
Here are some examples of my well ventilated garden room during summer.
During the drying period, it’s crucial to allow proper ventilation in the room to facilitate the drying process and prevent excessive moisture buildup. It’s also recommended to avoid touching or disturbing the plaster while it’s drying to prevent any damage or imperfections.
To ensure that the plaster is completely dry before proceeding with further work, you can perform a touch test. Gently touch the surface of the plaster with the back of your hand. If it feels cool or damp, it’s an indication that it’s still drying. Once the plaster feels dry and slightly warm to the touch, it’s likely ready for the next steps, such as sanding, painting, or applying additional finishes.
Painting plaster
The wall is now ready to be wallpapered or painted. If you are going to paint it, apply an undercoat first to seal the plaster, or your paint will just sink into it and could crack as it dries too quickly. If you are papering, apply a couple of coats of wallpaper adhesive and leave it to dry before hanging the paper. This will act as a bond between the two.
I painted my walls. To do so, the first layer of paint was mixed 50/50 with water. This allows the dry plaster to absorb some of the water as it dries which prevents cracking and uneven textures.
You can then finish painting the walls with normal matt emulsion paint.
And here’s an example of a finished garden room.
You can read all about this garden room build here:
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