Proper surface preparation is essential to achieve a professional and long-lasting paint finish. Whether the plaster is new, previously painted, or wallpapered, each condition requires specific steps to ensure paint adheres correctly and the final result is smooth.
Required Tools
Before beginning, ensure you have the following items:
- Sandpaper (180-grit) and sanding block
- Scraper, filling knife, stripping knife, wallpaper scorer
- All-purpose filler
- Sponge, bucket, brush, vacuum
- Emulsion paint, roller tray, 3-inch brush, 9-inch roller
- Painter’s tape and dust sheets
New Plaster Walls
New plaster must be fully cured and sealed before painting to prevent paint absorption and ensure even coverage.
Drying Time
Allow 1–2 weeks for plaster to dry. It should change from dark brown to an even pale pink. Do not paint over areas that are still discoloured or damp.
Surface Smoothing
Use a scraper to remove any raised edges. Lightly sand uneven sections with 180-grit sandpaper.
Mist Coat
Apply a mist coat to seal the surface. Mix three parts emulsion paint with one part water. Use a brush and roller to apply the coat evenly, and allow it to dry completely before proceeding.
Top Coat
Once the mist coat has dried, apply the top coat using standard application methods—cut in edges with a brush, then use a roller for full coverage.
Existing Plaster
Older walls may contain damage, dirt, or loose materials that interfere with paint adhesion.
Cleaning
Wipe the surface using a sponge and clean water. Allow at least one to two hours for the wall to dry before continuing.
Repairs
Fill all holes, cracks, or surface damage using a filling knife and all-purpose filler. Apply from multiple angles to ensure full coverage.
Sanding
Once the filler has dried, sand all repaired areas. Remove dust with a brush and vacuum the base of the wall and surrounding areas.
Painting
When the surface is dry, clean, and level, paint using a brush and roller as appropriate.
Wallpapered Surfaces
Painting directly over wallpaper is not recommended, as paint can loosen the adhesive and cause peeling.
Removal
Score the wallpaper with a wallpaper scorer. Soften adhesive by applying warm water with a sponge, then remove using a stripping knife. Use a steam stripper for difficult sections.
Surface Repair
After removing wallpaper, fill any visible holes or cracks using a filler. Once dry, sand the surface to remove any remaining adhesive or residue.
Final Steps
Clean the wall thoroughly, then proceed with paint application using standard techniques.
HB Plaster provides professional plastering and surface preparation services to ensure clean, paint-ready finishes. Our team is PASMA and IPAF accredited and holds CSCS certification. We operate throughout Wiltshire and the South West, including Salisbury, Cheltenham, Bath, and Oxford.
For assistance with plastering or full wall preparation, contact our team for expert support and service delivery.
FAQs
Yes. Dirt and dust prevent proper paint adhesion and may result in an uneven finish.
Yes, for existing walls and filled areas. New plaster typically requires minimal sanding unless imperfections are present.
Paint lighter colours first. Once dry, protect the area with painter’s tape before applying the darker shade.
This is not recommended. Clean and sand the surface to improve adhesion and avoid peeling.
Wait one to two hours or until the surface is fully dry.
