Guide
How to Prepare Walls for Paint, Wallpaper or Tile
The finish changes the preparation standard. Paint needs an especially uniform surface, wallpaper can hide some minor texture, and tile needs a strong plane with compatible adhesion.
Prepare a wall for the finish you actually plan to use. Paint highlights unevenness, wallpaper can hide some minor texture, and tile needs a strong, stable plane for adhesive. All three start with removing loose material, dust and the source of any moisture.
Start with the substrate
- Identify whether the base is concrete, plaster, filler, drywall or an older coating.
- Remove debonded areas and check whether dust remains on your hand after cleaning.
- Inspect cracks, damp marks, mould and signs of a leak.
- Check flatness and corners with tools suited to the finish and the room.
Preparation for paint
Paint exposes scratches, shadows and differences in absorption. A consistent repair sequence, careful sanding and a primer compatible with the substrate and paint are usually important. The number of coats and coverage still depend on the product and the colour below it.
Preparation for wallpaper
Wallpaper needs a sound, clean and sufficiently uniform surface without active moisture or large projections. Textured wallpaper may disguise small irregularities, but it cannot replace crack repair or removal of loose layers. Choose primer with the wall and wallpaper adhesive in mind.
Preparation for tile
Tile adhesive must bond to a compatible, strong and sufficiently flat substrate. Paint residue, powdery plaster and dust reduce adhesion. Drywall, plaster and old tile each have different preparation rules, so follow the adhesive and primer system instead of transferring advice from another surface.
Primer is not levelling
Primer regulates absorption and helps prepare a surface, but it does not correct major changes in plane or endlessly strengthen a weak layer. Choose the levelling method first, then prepare the finish layer and apply compatible primer.
A sensible order of work
- Correct moisture and any construction-related cause of damage.
- Remove weak finishes and level the surface with a suitable material.
- Wait until each layer reaches the condition stated by its manufacturer.
- Prime and apply the chosen finish according to its own instructions.
Frequently asked questions
Can wallpaper go directly over plaster?
Only after checking strength, dryness, flatness, cleanliness and compatibility with the adhesive. Fresh or dusty plaster needs preparation.
Must every wall be filled before tile?
Not necessarily. The requirement is a strong, flat substrate suitable for the tile adhesive system; an unnecessary extra layer can be incompatible.
Can I paint over old paint?
That depends on adhesion, the old coating and compatibility with the new system. Loose or glossy layers need assessment and preparation first.
How do I estimate primer?
Use the prepared area, coverage from the chosen primer and number of coats in the Primer Calculator.