How to Plaster a Wall: A Step-by-Step Guide

Plastering a wall is one of the most satisfying DIY projects—you go from rough and patchy to smooth and paint-ready. But to get a flawless finish, preparation, the right tools, and good technique are essential. Follow this comprehensive, step-by-step guide to plaster a wall like a pro.

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Tools and Materials You’ll Need

Tools:

• Hawk (plaster board)

• Trowel (stainless steel, ideally pre-worn in)

• Bucket trowel

• Mixing bucket

• Power drill with a paddle mixer (or manual whisk for small jobs)

• Paintbrush or water spray bottle

• Dust sheets and masking tape

• Spirit level or straight edge

• Sandpaper or sanding block (fine grit)

• Ladder or platform (if needed)

Materials:

• Multi-finish plaster (or other finish plaster)

• PVA (polyvinyl acetate) glue

• Clean water

• Jointing tape or scrim tape (if covering plasterboard)

• Optional: bonding plaster (for deep or uneven surfaces)

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Step 1: Prepare the Wall

Time: 30–60 minutes
Importance: Essential

1. Clean the surface – Remove wallpaper, dust, flaky paint, nails, or any loose material from the wall.

2. Check for damage – Fill deep holes with bonding plaster or filler. Let it dry.

3. Apply scrim tape – If you're plastering over plasterboard, tape all the joints and corners with self-adhesive scrim tape to prevent cracking.

4. Seal the wall – Mix PVA with water at a ratio of 1:4. Apply it evenly using a roller or large paintbrush. This prevents the wall from sucking moisture out of the plaster too quickly.

5. Let it go tacky – Don’t let the PVA fully dry. Start plastering while it’s still slightly sticky to the touch—usually after 15–20 minutes.

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Step 2: Mix the Plaster

Time: 10–15 minutes
Tip: Always add plaster to water, not the other way around.

1. Fill a clean bucket with cold water (about a third full, depending on the area you’re covering).

2. Gradually add the plaster powder while stirring with a paddle mixer or manual whisk.

3. Mix until it’s the consistency of thick yoghurt—smooth with no lumps.

4. Let it sit for a minute, then give it a final stir before applying.

✅ Top Tip: Only mix as much plaster as you can apply in 25–30 minutes, especially if you're new to plastering.

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Step 3: Apply the First Coat (Base Layer)

Time: 60–90 minutes (depending on wall size)

1. Load your hawk with plaster using the bucket trowel.

2. Using your trowel, scoop a small amount and spread it onto the wall, starting from the bottom left (if right-handed).

3. Apply firm pressure to squeeze the plaster onto the wall in upward strokes.

4. Aim for a layer about 2 mm thick—don’t worry about perfection at this stage.

5. Work in manageable sections, overlapping slightly to avoid dry lines.

6. Once the whole wall is covered, use your trowel to smooth over any ridges or thick edges.

🔧 Tip: Keep your tools clean at all times—dried plaster can ruin your finish.

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Step 4: Apply the Second Coat (Finish Layer)

Time: 30–60 minutes after first coat

1. Once the first coat starts to firm up but is still damp (you should be able to touch it lightly without much indentation), mix a fresh batch of plaster.

2. Apply a second, thinner coat—about 1 mm thick.

3. This coat should be smoother and more even than the first. Use long, sweeping strokes.

4. Fill in any holes or hollows left from the first layer.

5. Feather the edges and blend sections together as you go.

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Step 5: Trowel and Polish

Time: 3 stages over 60–90 minutes

This stage is all about achieving that glass-like finish. As the plaster begins to dry (it will darken), go over it multiple times to smooth it further.

First Trowel (just after second coat starts setting):

• Lightly mist the wall with water using a spray bottle or a damp brush.

• Glide your clean trowel over the surface to flatten ridges and fill tiny holes.

Second Trowel (30 mins later):

• Continue polishing, focusing on problem areas.

• You can use a small amount of water on your trowel edge to help with smoothing.

Final Trowel (final pass before plaster is fully dry):

• For a mirror finish, go over the wall with firm pressure.

• You can also use a plastic float or corner trowel for edges.

🎯 Top Tip: The more you polish before the plaster fully dries, the less sanding you’ll need later.

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Step 6: Let It Dry and Sand If Needed

Time: 2–5 days drying, 10–15 mins sanding

• Allow the plaster to dry naturally. You’ll see it lighten from dark pink to pale buff.

• Avoid forced drying with heaters or fans—it can cause cracking.

• Once dry, lightly sand any uneven spots with fine-grit sandpaper.

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Step 7: Paint or Decorate

• Mist Coat First: Apply a mist coat (a 70:30 mix of water and white emulsion) to seal the plaster and create a good base for decorating.

• Once dry, follow with your chosen paint or wallpaper.

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Frequently Asked Questions

Can I plaster over paint or wallpaper?

Only if the surface is well bonded and free from peeling. Otherwise, strip it back and apply a bonding agent like PVA.

How long should plaster dry before painting?

Allow at least 4–5 days in average UK conditions. It should be completely light pink/beige before painting.

What’s the easiest wall for a beginner to plaster?

Start with a small internal wall or a single face of a plasterboard wall for practice.

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Final Thoughts

Plastering takes patience, but the results are worth it. With good prep, the right tools, and steady technique, you can achieve a smooth, professional-looking wall ready for decorating. If it’s your first time, consider practising on a small area or even a plasterboard offcut before tackling an entire room.