Plan your project

Step 2 - How much paint do you need?

Use the Dulux Weathershield paint calculator to find out

Don't guess - use this calculator to work out just how many litres you will need.


What are you painting?

Step 3 - What to do before you start

If your exterior walls have been painted then they will need to be maintained. This is a big job that requires a lot of planning and thought before you start to ensure that you have all the necessary tools and equipment before you start. A high level of surface preparation is essential if the job is going to look good and last a long time.

Essential tools and preparation advice

  • If the surface is very bad then it may be necessary to wash some of it down first with a detergent solution to remove dirt, grease etc. Obviously this is not an easy thing to do on the outside of a house, but it will help give the best results. Rinse off with clean water and allow too dry.
  • Carefully scrape back to a firm edge all areas of poorly adhering or defective coatings and rub down thoroughly to "key and feather" broken edges of existing coatings. Don't use a wire brush as bits of the wire may break off embedding themselves in the surface, which may rust when the water-based Weathershield masonry paint is applied. Treat any areas affected by mould, lichens, algae and moss with Dulux Weathershield Fungicidal Wash. Make good minor defects with an appropriate Polycell filler.
  • New or sound bare surfaces should be sealed with a thinned first coat of the Weathershield masonry paint (smooth or textured) to ensure good adhesion of the finishing coat(s). Surfaces that remain powdery, friable or chalky after thorough preparation should be sealed with a coat of Dulux Weathershield Stabilising Primer, but never seal sound, new or bare surfaces with stabilising primer as it will do more harm than good.

Painting advice

  • Weathershield masonry paints are designed to let the walls breathe so if you apply a glossy sealer that is not required then any moisture vapour passing through the paint film will condense on the glossy sealer causing the masonry paint to blister and flake.
  • If your walls have never been painted then you need to think very carefully about what you are doing if you decide to paint them. Once painted they must be maintained and it is very expensive and difficult to go back if you change your mind. Professional blast cleaning is the only way to do it. Also, a lot of bricks can't be painted such as Fletton or Common Bricks. Always seek professional advice if in doubt.
  • Painting metal gutters and pipes outside: The inside of metal gutters are best coated with a layer of a suitable bitumen-based paint for protection against damp conditions. The outside, brackets and downpipes can all be painted with either normal Dulux Professional Undercoat and Gloss or the Weathershield Undercoat and Gloss. Any bare areas of metal must be prepared and primed with Dulux Metal Primer first.
  • Painting Plastic Gutters and Pipes Outside: Plastic gutters and pipes are normally left unpainted but if they have discoloured then they are best painted by applying 2 coats of gloss paint direct to the cleaned plastic. Primers and undercoats are not required.
  • Stripping Wood: There is no need to strip existing paint coatings unless they are in a very bad state. It is always better to continue painting and build up the surface than to start again from bare wood
  • If you do have to strip down to bare wood, use Polycell Advanced Paint Stripper.