How to plaster a wall

Inspired by the official Wickes how-to guide. This walk-through is based on the Wickes tutorial "How to plaster a wall | Wickes", which takes you through the whole process clearly — including the bits that catch beginners out. Worth watching in full before you open a bag of plaster; the setting stages alone will save you a lot of grief.

1. Prepare the surface thoroughly

Any loose material, flaking paint, or old filler has to come off first. Tap plasterboard or bare brick to check for hollow spots; fix any you find before you start.

Brush down the wall to remove dust and debris. A clean surface is not optional — it is the only reason the new plaster sticks and stays.

2. Apply a PVA bonding coat

Mix PVA with water at roughly 1 part PVA to 5 parts water for the first diluted coat. Brush it evenly across the whole area and let it dry until tacky but not fully cured — usually 20 to 30 minutes depending on temperature.

On very porous surfaces like bare brick or blockwork, apply two PVA coats. On plasterboard, a single bonding coat is usually enough. Mind you, skip this step and the plaster will simply slide off.

3. Mix your plaster to the right consistency

Add plaster to clean water, not the other way around. Use a clean bucket and a mixing paddle on a slow-speed drill. You are aiming for a thick, smooth, lump-free mix — roughly the consistency of thick yoghurt.

Work quickly. Multi-finish plaster typically gives you about 20 to 25 minutes before it starts to set. Mix only as much as you can use in one go.

4. Apply the first coat with a plastering trowel

Load your hawk with a manageable amount of plaster. Use a steel plastering trowel to sweep it onto the wall in upward strokes, working from the bottom of the area upward. Aim for an even coat about 2 to 3 mm thick.

Don't try to make it perfect at this stage. You just want an even, consistent coverage across the whole area before it starts to go off.

5. Rule off and scratch the surface

Once the first coat is on, use a long straight edge (or a plasterer's rule) to flatten high spots. Then scratch the surface lightly with a comb float or the edge of your trowel before it fully sets — this gives the second coat something to grip.

To be fair, if you are doing a small patch rather than a full wall, you can sometimes get away with a single coat of finishing plaster. But for larger areas, two coats give a much better result.

6. Apply the finishing coat

Mix fresh plaster and apply a second, thinner coat over the scratched first coat. Work it out to about 1 to 2 mm thick. This is the coat that will give you your finished surface, so take your time and work methodically.

Keep a bucket of clean water and a wet brush handy. A quick mist of water on the surface as the plaster begins to firm up helps you achieve a smoother finish when you polish it.

7. Polish the surface to a smooth finish

As the plaster stiffens — you can tell because it starts to lose its sheen — use a clean damp trowel held almost flat against the wall and work it in firm, overlapping circular passes. This compresses the surface and closes any small imperfections.

Repeat the polishing pass once more as the plaster gets firmer still. Three passes total is usually enough. If you start to drag or pull the plaster, stop. It's too late to work it further at that point.

8. Allow to dry fully before decorating

Fresh plaster takes longer to dry than most people expect — a full wall can need anywhere from one to four weeks before it is genuinely ready to paint, depending on thickness, ventilation, and temperature.

Keep the room ventilated but avoid direct heat. Watch the colour: new plaster starts dark and gradually lightens as it dries. Only decorate once it is uniformly pale. Apply a mist coat of watered-down emulsion before full paint, otherwise the plaster will suck it straight in and you'll get patchy coverage.

When to call a handyman

Call Richard if you are covering a large area, dealing with damaged corners or coving, or the wall is cracked and you are not sure of the cause. Plastering a whole room to a good finish is a skilled job — a professional will do it faster, smoother, and with less mess than a first-timer attempting it alone.