How to paint exterior walls


Tools for the job:

Working safely

For maximum safety and efficiency we recommend planning your exterior painting project carefully and making sure you have all the right equipment in advance.

  • Use dust sheets and masking tape to protect surfaces from paint.
  • Make sure ladders, steps or access towers are secure and positioned safely according to the manufacturer's instructions.
  • Wear protective gear like goggles, gloves,overalls and masks.
  • Have cleaning materials to hand to deal with any possible spillages or contamination.

Preparing exterior walls

Brush away any debris, remove old paint and wipe surfaces with a wet sponge before you start painting, so dust and flakes won’t fall on your wet paint. Just like an interior room, sand flat surfaces down and fill any cracks with an exterior filler

Start from the top of your house and work down, cleaning out gutters and painting them if necessary.

When removing old flaking masonry paint, use a scraper where possible. A stiff bristle brush will remove small residual flakes. 

It’s important NOT to use a wire brush on masonry surfaces, as metal particles can become embedded on the surface. These react to the water-based masonry paint, resulting in potential rust spots that will make walls look unsightly. When removing old paint we recommend wearing safety glasses, gloves and a mask to reduce the risk of damaging your eyes or breathing in dust particles.

Organic mould growth

If you see mould growing on an exterior wall, it’s important to treat it effectively, otherwise it will come through on newly painted areas.

Where there’s a particular mould issue, first remove any surface contamination with a scraper, then use a stiff bristle brush. Once the surface is sound it’s important to apply a fungicide solution, diluted with water according to the pack instructions. As fungicides are usually bleach based, we recommend wearing gloves and safety glasses.

Apply the fungicide solution to the affected area, plus an overlap, to make sure the solution penetrates the surface and kills the mould growth. Again check the manufacturer’s pack instructions to find out how long to wait before painting over the fungicide solution - this is usually 24 hours. Masonry paint will adhere better to a clean surface.

Mould tends to grow in damp conditions so it’s important to deal with the cause of the problem, as well as the mould itself.  For example, a leaking gutter might be creating a damp area.

Unstable surfaces

It’s important to treat chalky or dusty surfaces on exterior walls, otherwise your new coat of paint will stick to the loose dust particles and blister.

Wipe your hand on the surface you’re about to paint and if you get dusty particles on your hand you’ll need to use a stabilising solution. Simply apply the stabilising solution direct to the surface using a three inch brush and let it dry for 24 hours before starting to paint your wall. The stabilising solution seals and stabilises the surface so you’ll get good coverage from your masonry paint.

Buying paint

How much paint do you need?

It sounds obvious but make sure you buy plenty of paint to complete your project.

To work out how much paint you need to paint your house, follow this simple calculation:

Measure the length of each surface and multiply by height.

This will give you the area in square metres (for example, a wall measuring five metres long and three metres high had a surface area of 15 square metres).

How much paint
Types of paint

Masonry paint is for your exterior walls, available in smooth or textured finish.

Gloss & Satin paint is used for front doors and windows, it is available in gloss for a traditional high shine finish, or satin for a modern mid sheen finish.

Multisurface paint is perfect for use on all wood, metal and uPVC surfaces.

Choosing a colour

Exterior paints are available in a great range of colours and we recommend buying tester pots and getting inspiration from the manufacturer’s colour cards and website before choosing your favourite shade. Remember a paint colour will look different depending on the natural light available and the colour adjacent to it, such as a green lawn.

It’s a good idea to put colour from a tester pot onto a piece of card and position it at different points on your property, perhaps at different times of day.

Textured or smooth?

Masonry paints are available in two finishes, textured or smooth. Both protect your walls, as well as decorating them.

Textured paint contains fine particles, which provide extra durability - and it’s a great option where walls are exposed to the elements. It’s easy to tell when you haven’t applied textured masonry paint thickly enough, as it will break up – and this helps as a guide to applying the paint correctly.

Smooth paint is an easier alternative for applying over a large area.

There’s also the option of ‘One Coat’ which has a higher colour content and will save you time.

How to paint your exterior walls

Starting at the top, paint in sections working from right to left, or left to right. Work your way across the house, first painting the top, then the middle and finally the lower part. Try to maintain a wet edge so you don’t have stripes or blocks appearing on the wall where the paint has dried unevenly.

To make sure your paint dries effectively, apply it when the temperature is 8°c or above and surfaces are free from damp and dew. Avoid painting in direct sunlight as this can lead to blistering.

Brush or roller?

A three or four inch masonry brush is ideal for cutting in edges and for painting small and ‘hard to reach’ areas.

A roller with a medium to high pile sleeve gives you a quicker way of painting larger areas. Adding an extension pole is an even faster way to paint big surfaces.

When you’re using a roller apply more pressure on the upward stroke as this is when paint is delivered to the surface. Use less pressure on the downward stroke, when the roller takes paint away and there’s potential for it to spatter.


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