Rochele Painter sanding wall to prepare to paint

The number one cause of paint failure is when the surface is prepared poorly. The first and most crucial step is preparing the surface you are about to paint.


  • Wash the surface with mild detergent or sugar soap to remove dirt. Treat any mould and allow to dry
  • Any interferences need to be removed such as electrical face plates, knobs, handles, locks etc. Anything that cannot be moved can be masked or covered where possible.
  • Any imperfections or loose paint needs to be sanded. To ensure the new paint can bond to the surface any gloss surfaces need to be dulled by sanding. A mask is important to be worn when sanding and also ensure the dust is cleaned up afterwards.
  • Old paint or varnish on wood needs to be removed entirely so use a paint stripping gel, wash down and allow to dry then sand lightly

Painting the surface

  • Any marks need to be sealed with an appropriate sealer so that it avoids bleeding through to the new paint. New, repaired or patched surfaces will require a coat of primer or undercoat before painting. Check the label on the topcoat tin for priming instructions on the surface you are painting.
  • Water based paint can generally be painted over existing water based paint without an undercoat if the old coat is in good condition.
  • Oil based paints will require an undercoat if the old and new paint is oil based or if using a water based topcoat you should undercoat with a primer-sealer-undercoat
  • Bare wood needs to be primed with a wood primer or a primer-sealer-undercoat to ensure long term adhesion of the paint and avoid any tannins from the timber staining the new topcoat
  • Rust needs to be removed and the metal primed with an appropriate metal primer