How to paint exterior walls
& wood

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To paint exterior walls and wood, you will need...

Things to think about when painting exterior walls and wood

• Safe access is always important when painting outside. Consider hiring fixed scaffolding if you need to work at height.
• Where wood is in poor condition with many layers of paint, you may want to strip back to bare wood using paint stripper or a hot air gun. Take all recommended safety precautions if you do this.
• Use paint that is specified for exterior use. For walls the most commonly used paint is exterior emulsion, which is generally called masonry paint. This is a water-based paint and dries quickly. Two coats are always recommended.
• Any algae or mould on external walls must be treated with a fungicidal solution and washed down before any paint is applied. Most exterior paint does contain fungicide, but, in areas of extensive growth, a fungicidal wash is appropriate preparation.
• Ideally paint two undercoats on woodwork before the gloss topcoat is applied. It is now possible to buy mid-sheen finishes (such as eggshell) for exterior woodwork. Rather than using undercoats, you may just apply 2-3 coats of the finish.
• When estimating quantities for exterior painting, be guided by the coverage rates supplied by the paint manufacturer. This can differ greatly from brand to brand, and is also dependent on whether you are painting a bare masonry surface or a previously painted one.
• If using a varnish, stain or oil, sanding with a palm sander is often necessary to remove all old finishes before a new finish can be applied. Most varnishes and stains are 2-3 coat systems. Oils may require more coats and will certainly need a further maintenance coat at least once a year in order to retain the wood colour.
• Metal surfaces, such as guttering, should be cleaned down with a wire brush, and any bare metal primed with a suitable metal primer before undercoats and topcoats are added. Alternatively, use a specialist metal paint that requires no primer.
• Areas of rot must be treated or replaced before decoration. Small areas of rot can be cut out with a scraper, and allowed to dry before applying a wood hardener. The hole may then be filled with a two-part, epoxy-based filler that will dry to an extremely hard finish, which, once sanded, may then be painted.
• Plastic guttering and UPVC windows can be cleaned down with a mild detergent solution. It is also possible to buy paint for coating uPvC windows. Plastic guttering can also be painted, with two coats of gloss being a recommended system.

Step by step guide to preparing and painting masonry

Step 1

Any flaky paint must be removed and the surface cleaned down. A pressure washer is the ideal tool for cleaning off the surface.

Step 2

Cracks in render should be filled with exterior filler. Mix as directed and use a filling knife to press the filler firmly in place.

Step 3

Allow the filler to go off (partially set) and then use a sponge to smooth off the surface. This reduces the need to sand off excess filler when dry.

Step 4

Any powdery surfaces must be treated with a stabilising solution. This binds the surface making it in a good condition to accept paint.

Step 5

Once preparation is complete, a roller is ideal for applying paint. However, on rough render surfaces, a large brush is the best tool.

Step 6

A brush is also required for finishing off around the edges neatly and precisely, such as next to doors or windows, or where the wall meets the ground.

Step by step guide to preparing and painting wood

Step 1

Most wood simply requires sanding and cleaning down with sugar soap before paint is applied.

Step 2

In wooden windows, remove any loose putty with a putty knife and dust out the rebates thoroughly.

Step 3

Any bare areas should be patch primed. Any new wood should be knotted and primed completely.

Step 4

Putty needs to be worked in your hands before use. A layer of powder filler on your hands makes this easier.

Step 5

Roll the putty in your hands into small sausages, slightly larger than the size required to fill gaps. Keep working the putty until it contains no lumps.

Step 6

Press the putty lightly into place with your fingers, ensuring good contact between the wooden edge of the rebate and the glass.

Step 7

Use a putty knife to smooth along the putty surface and create a neat finish. One or two passes of the knife may be required.

Step 8

Allow the putty to dry for a few days before priming and further painting. Small cracks in old putty can be filled with some exterior, all-purpose filler.

Step 9

Once the filler is dry, sand the area until smooth, taking care not to scratch the glass surface with the sandpaper.

Step 10

After a final dust off to ensure the cleanest surface for painting, preparation is complete. You are now ready to apply your chosen exterior paint system.

The expert practical advice contained in this leaflet assists you in carrying out your home improvement projects both safely and successfully.
If in doubt take professional advice and always follow manufacturers' instructions.

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