Plastering a wall can be a bit messy and requires some skill, but with the right steps, you can achieve a smooth, durable finish. Here’s how to do it:
Materials Needed:
- Plaster (either premixed or powder to be mixed with water)
- Water
- Bucket
- Mixer drill or a stick for manual mixing
- Plastering trowel
- Hawk (a flat board with a handle underneath)
- Straight edge or darby
- Sandpaper or sanding block
- Protective gear (goggles, dust mask, gloves)
- Drop cloths or plastic sheets
Steps:
- Preparation:
- Clean the Wall: Ensure the wall is clean, dry, and free from dust, grease, or loose material. Remove any old, loose plaster.
- Protect Surrounding Areas: Lay down drop cloths or plastic sheets to catch plaster spills. Tape off adjacent walls, ceilings, or trim if necessary.
- PVA Bonding Agent (Optional but recommended):
- Apply a coat of PVA glue mixed with water to the wall to help the plaster adhere better. Follow the manufacturer’s ratio for mixing.
- Mix the Plaster:
- If using powder, mix it according to the manufacturer’s instructions. Aim for a consistency similar to thick custard. Use a mixer drill for best results to avoid lumps.
- Application:
- Load the Hawk: Scoop some plaster onto your hawk.
- Apply the First Coat (Scratch Coat):
- With the trowel, apply plaster to the wall starting from the bottom. Use firm pressure to spread the plaster upwards at an angle.
- Aim for about 5mm thickness for the first coat.
- Once you’ve covered a section, use a straight edge or darby to level it.
- Before this coat fully sets, scratch it lightly with a scratcher or a trowel to create a key for the next coat (hence “scratch coat”).
- Second Coat (Brown or Base Coat):
- After the scratch coat has hardened but not completely dried (usually after a few hours), apply another layer. This should bring the total thickness to about 10-15mm.
- Again, level this coat with your straight edge.
- Finishing Coat (Finish Plaster):
- Once the brown coat is firm but still damp, apply a thinner layer of finish plaster if using a two-coat system, or directly proceed if your plaster is for finishing as well.
- This layer should be smooth and even, typically around 2mm thick. Use the trowel to create a flat, smooth surface.
- Smoothing and Polishing:
- When the plaster starts to set (after it has lost its wet shine but is still soft), use the trowel to smooth out any lines or bumps. Wet the trowel slightly for a smoother finish.
- For an extra smooth finish, you can lightly mist the wall with water and go over it with a clean, wet trowel.
- Drying:
- Allow the plaster to dry. This can take several days to a few weeks depending on conditions.
- Sanding (if necessary):
- Once completely dry, sand any imperfections lightly with fine-grit sandpaper for an even finish.
- Cleanup:
- Clean your tools immediately after use before the plaster sets.
Tips:
- Ventilation: Ensure good ventilation to help the plaster dry evenly and to clear dust if you’re sanding.
- Temperature: Avoid plastering in very cold or very hot conditions as it affects setting time and quality.
- Practice: If you’re new to plastering, practice on a small area or a piece of plasterboard first.
Remember, plastering can be quite an art, so patience and practice will improve your results significantly.
