Painting exterior wood

Posted on May 21, 2018 in Building Maintenance

Painting exterior wood

Safe access is always important when painting exterior wood. 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.

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.

  • Most wood simply requires sanding and cleaning down with sugar soap before paint is applied.
  • In wooden windows remove any loose putty with a scraper or putty knife and dust out the rebates thoroughly.
  • Any bare areas must be patch primed. Any new wood should be knotted and primed completely.
  • Putty needs to be worked in your hands before use. A layer of powder filler on your hands makes this easier.
  • Roll the putty in your hands into small sausages, slightly larger than the size required to fill the gaps. keep working the putty until it contains no lumps.
  • Press the putty lightly into place with your fingers, ensuring good contact between the wooden edge of the rebate and the glass.
  • 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. Allow the putty to dry for a few days before priming.
  • Small cracks in old putty can be filled with some exterior all-purpose filler.
  • Once the filler is dry, sand the area until smooth, taking care not to scratch the glass surface with the sandpaper.
  • 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.

Exterior Wood Painting

If you choose to use a gloss system, ideally paint two undercoats on the woodwork before the gloss topcoat is applied. The alternative is to use a mid-sheen finish (such as eggshell) – in this case, rather than using undercoat, you just apply two to three coats of the finish.

Always be guided by the paint manufacturer on the quantity you require, but bear in mind that 2.5 litres will go a long, long way if you are just painting windows.

Any areas of rot must be treated or replaced before painting. 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.

If you’re recoating previously varnished, stained or oiled wood, sanding with a palm sander is a good way of removing the old finishes before a new one is 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.

For advice on outside walls, please see our guide ‘Painting exterior walls’ or for information on our painting service visit Protech Painting and Decorating Solutions.

Our Guarantee To You

We created the Protech guarantee because we want you to put your trust in our painters and decorators. Under this minimum one year guarantee, if anything goes wrong as a direct result of the work our engineers perform in your home or business, we will return to inspect the problem. If the fault is found to be due to our engineer’s work, we’ll fix the problem with no cost to you.


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