how to plaster a wall

How To Plaster a Wall Like a Pro (Step-by-Step DIY Guide)

Plastering is one of the most challenging DIY jobs to master, but you can do it with practice, perseverance, and professional guidance. 

I remember my early attempts at plastering ending in disaster, with most of the plaster landing on the floor! Luckily, at the time, I was working on a large housing project with plenty of plasterers on-site. 

The pros guided me through the process, step-by-step, and before long, I plastered an entire wall! Since then, I’ve perfected the technique described in this DIY plastering guide.

So, if you want to know how to plaster a wall, read on.


Plastering Different Types of Walls

The steps required to plaster a wall differ based on the wall you’re plastering, which in most cases will be masonry or plasterboard.


Plastering onto Masonry

room with red brick wall

By masonry, we mean blockwork and brickwork. 

Because of masonry’s uneven nature, it requires a thicker coat of plaster to create a flat base on which to apply the finishing coat. Typically, you should use a base coat of 13mm, but this can be more on older walls. You might even need a render coat first to cover cracks and bulges.

Masonry is also porous, so to prevent it from sucking the moisture out of the plaster as you apply it, give the wall a coat of PVA. The PVA acts as a primer and helps bond the plaster to the surface.


Plastering onto Plasterboard

room with plasterboard wall

It’s much easier to plaster onto a plasterboard because you have a smooth finish to work from. 

Also, plasterboard doesn’t require as much preparation. For instance, you don’t need PVA, and you only need to apply a skim coat, if that.

I discuss the pros and cons of ‘skim coat’ vs ‘tape and fill’ in our guide on how to build a stud wall.

Pro Tip: If you’re plastering an old masonry wall, consider applying plasterboard using the ‘dot and dab’ method described in our guide on plasterboarding a brick wall.


Types of Plaster

In the UK, gypsum is the most commonly used plaster. 

Gypsum is made from dehydrated gypsum with additives to make it harder. British Gypsum is the leading supplier of gypsum plaster, and they have a vast range to choose from — check out our types of plaster guide to see the top 11.

You may have heard of lime plaster, but unless you’re working on an old or listed building, you don’t need to concern yourself with this type of plaster. If, however, you want to learn more about lime plaster, this video by A&E will show you everything you need to know.

There are three categories of plaster: base coat, finishing coat (AKA skim), and one-coat plaster.

Base Coat

thistle bonding coat

Terms you might come across are browning and bonding plasters, and both are used as a base on which to apply the skim coat. 

There are many variants for use in all kinds of situations. For example, ‘hardwall’ and ‘tough coat’ are typically used in areas prone to impact damage. However, for most applications, British Gypsum’s Bonding Coat is ideal.

Finishing Coat

thistlepro fastset finish plaster

Finishing plaster is commonly used to skim over a base coat or onto a plasterboard wall. If you want to get the job done fast, Thistlepro FastSet Finish is a great choice.

Note: You can spray on some finishing coats, but this method is one for the experts.

One-coat Plaster

thistle universal one coat plaster

Sometimes, you only need plaster to patch up or repair a damaged wall, which is where one-coat plaster comes into its own. 

You can apply British Gypsum’s Universal OneCoat in coats of over 25mm and still get a smooth finish that you paint or paper over.

Pro Tip: Use this British Gypsum calculator to calculate how many bags you need for your plastering project. The most convenient bag size for large areas is 25kg.


Tools and Materials

Using the right tools for the job is essential if you want to plaster like a pro.


Tools

  • Plastering bucket 30 litres
  • Bucket trowel
  • Electric drill with a mixing paddle
  • Spot board (a 1m2 sheet of plywood will do)
  • Plastering hawk
  • Plastering trowel
  • Finishing trowel
  • Spray bottle
  • Paintbrushes 38mm and 75mm wide
  • Step ladder

Materials

  • Protective sheeting
  • PVA
  • Basecoat plaster
  • Finishing plaster
  • Angle bead and tin snips, if required

Health and Safety Measures

Wear goggles, a face mask, and gloves when mixing plaster because gypsum can cause respiratory problems and irritate skin and eyes.


How To Plaster a Wall — Step-by-Step Instructions

To plaster a wall like a pro, follow the steps below.

Pro Tip: I recommend practising the steps below on a small area before you attempt plastering an entire wall.


Step 1: Preparation

plastic sheet covering table

Turn off the room’s power supply, and then remove the front plates of all light switches and plug sockets. 

Remember, it doesn’t take long to set, so have everything ready to apply your freshly mixed plaster immediately.

Use plastic sheeting to protect anything that must stay in the room and cotton sheets to protect the flooring.

Angle beads and stops

Not all walls are straight, so you may have to fix metal angle beads on corners or around window openings. You can fix these beads mechanically or with plaster dabs.

On masonry walls, it’s common to fix 13mm thick timber battens to the bottom of the wall to set the thickness of the plaster. You can then use these battens can for fixing the skirting.


Step 2: Mixing plaster

mixing bucket with unused plaster

Mixing plaster is the most critical part of plastering a wall. You must get the right consistency — too wet, and the plaster will slump to the bottom; too dry, and it won’t adhere to the wall. 

Follow these steps for the perfect mix:

  1. Pour water into the bucket. Check the manufacturer’s instructions, but as a guide, you need 25 litres of clean water per 25kg bag of plaster.
  2. Slowly add the plaster to the water, stirring as you go.
  3. Use a mixer paddle attached to a power drill to ensure all the powder is mixed with the water.
  4. To ensure all the powder is thoroughly mixed, use a bucket trowel to scrape around the perimeter of the bucket.
  5. Once you get the right consistency, stop. Don’t overwork the mix, as this can break down the components.

For more information on mixing plaster, watch the video below:

YouTube player

Once it’s thick enough to spread without being runny, move on to the next step immediately, as the plaster will begin to set pretty quickly.


Step 3: Plastering walls

plasterer holding plastering tools

Pro Tip: Wet the hawk and trowel first to ensure the plaster doesn’t stick or start to dry out too quickly. Next, add a thin coat of plaster to the hawk to prevent the plaster from slipping off.

  1. Transfer the mixed plaster onto a spot board. Note: you can work directly from the bucket, but working from a board is much easier.
  2. Scoop a small amount of mortar onto the hawk, to begin with. Once you get used to applying the plaster, you can add more.
  3. Spread the plaster from the hawk onto the wall using a trowel, starting near the top and working from left to right. Note: some pros recommend starting at the bottom left corner of the wall and working upwards and across. Use whatever method suits you.
  4. Use firm pressure and spread the plaster evenly over the wall, working in multiple directions — up, down, left, right, and in an arc — to get a smooth finish without ridges. Angle the trowel slightly so that only the long edge is in contact with the wall, and then flatten the angle as you near the end of the stroke.
  5. Pay attention to the bottom of the wall and smooth out any ridges, so you don’t have a problem when it comes to fixing the skirting.
  6. Once you’ve covered one wall, go over it again with a thin (2mm) coat to achieve a smooth flat finish. Depending on the type of plaster you’re using, you may have to mix some finishing plaster for this final coat.
  7. Use a narrow, dampened paintbrush to smooth out any corners and edges.
  8. Allow the plaster to dry for an hour before moving on to the next step.

Pro Tip: If you have to build up the plaster in layers because of the unevenness of the substrate, scratch the plaster surface with a finishing trowel before applying the next coat. These scratches provide a key for the plaster to stick to.


Step 4: Finishing Off

plasterer smoothing freshly plastered wall
  1. Wet the surface with a sponge, spray bottle or a wide paintbrush to get a shiny finish to the wall.
  2. Using the long edge of the trowel, work across the dampened plaster from left to right as before. Don’t use too much pressure, or you’ll scratch the surface.

And that’s it! All you need to do now is tidy up, clean your tools and wait for the plaster to dry before painting or decorating. 

The drying process can take up to two weeks, so don’t wait — get on with the next project! Consider plastering the ceiling now you know what to do.

Pro Tip: If you want to see the entire process, from mixing to finishing off, check out the video below:

YouTube player

Final Thoughts

There’s no doubt about it, plastering is challenging, and this prevents many people from giving it a go. However, if you carefully follow the steps above and keep practising, you too can master the art of plastering.

If you still don’t fancy trying it after reading this guide and watching the videos, use Rated People to find top-rated plasterers in your local area. Furthermore, our plastering cost guide will ensure you’re not paying too much for your next project.