How to Prepare Walls Before Painting or Hanging Wallpaper
By Designer Home Interiors - Designer Paint & Wallpaper | Lick | Published: 2026-10-15
Category: How-to Guides
A step-by-step guide to cleaning, filling, sanding and priming walls so paint and wallpaper look flawless and last longer.
Quick answer
Clean the walls first, then fill and sand any holes or cracks, and always prime bare plaster or patched areas before you paint or hang wallpaper. Skipping the clean-and-prime stages is the main reason finishes look patchy or wallpaper bubbles later.
Why preparation decides the finish
Paint and wallpaper both amplify whatever is underneath. A glossy or dusty surface stops paint bonding, and a wall that is not flat makes every seam and edge more obvious. The steps below work for both paint and wallpaper; where the two diverge, it is called out.
Tools and materials to gather
You will need a filler and flexible scraper, fine sandpaper (around 120–180 grit) or a sanding block, a tack cloth or slightly damp lint-free cloth, sugar soap or a mild degreaser, a primer suitable for your surface, and a roller and brush for priming. For wallpaper, add a paste-the-wall adhesive and a smoothing brush. Check the wallpaper instructions before you buy adhesive.
Step-by-step wall preparation
- Clear and protect the room: Move furniture out or to the centre and cover it, remove light switch covers and picture hooks, and lay dust sheets. Work from the top of the wall down so dust and drips do not fall on finished areas. Checkpoint: the floor and any remaining furniture are fully covered before you start.
- Clean the walls: Wash with sugar soap or a mild degreaser and rinse well, paying attention to kitchens and areas near handles where grease builds up. Let the wall dry completely. Common mistake: skipping the rinse leaves a soap film that stops paint and adhesive bonding.
- Fill holes and cracks: Use a fine-surface filler for small holes and a flexible filler for cracks at joints. Overfill slightly, because filler shrinks as it dries, then leave it to set fully. Common mistake: filling over a damp or dusty wall makes the filler fail; clean and dry first.
- Sand the filled areas: Once dry, sand flush with fine paper, feathering the edges so you cannot feel a ridge. Wipe away dust with a tack cloth. Checkpoint: run your hand over the patch; if you can feel a bump, sand again.
- Prime bare plaster and patches: Apply a suitable primer to bare plaster, filled areas and any glossy surface. This seals the surface so paint and adhesive grip evenly. Common mistake: painting or wallpapering straight onto bare plaster leads to patchy absorption and weak adhesion.
- Check the surface before you decorate: Look along the wall in raking light to spot dents or missed filler, and confirm it is dry and dust-free. For wallpaper, follow the paste-the-wall instructions for your chosen paper. Next step: once the wall is smooth, dry and primed, you are ready to paint or hang wallpaper.
Wallpaper options that suit a well-prepped wall
- Botanical 06: Botanical 06 is a smooth matt non-woven wallpaper with paste-the-wall application and a yellow and white leafy design. Smooth non-woven papers show wall imperfections more than textured ones, so filling and sanding matter more. Paste-the-wall means you paste the wall, not the paper, which keeps the process tidier.
- Safari 01: Safari 01 is a paste-the-wall wallpaper with a creamy white background and animal motifs, available as a roll or a sample. Ordering a sample first lets you check the colour against your primed wall and lighting before committing to full rolls.
- Mars Meadow 02: Mars Meadow 02 is a floral wallpaper featuring orange-based flowers. A bold floral pattern can distract from small wall flaws, but the wall still needs to be clean and sealed so the paper adheres evenly.
