Finishing a window frame outdoors

Finish a wooden exterior window frame with Osmo UV-Beschermingsolie or, for an opaque colour, with Osmo Landhuisverf. On a window frame, the sill is the most vulnerable part, because rainwater lies there longest. An oil-based finish soaks into the wood, lets it breathe and does not flake, so no moisture can get behind a layer.

Transparent with UV-Beschermingsolie

UV-Beschermingsolie protects vertical wood against UV light by a factor of 12 compared with untreated wood. Apply two coats: a coloured coat followed by a coat of 420 clear, or two coats of 420. We advise against two coloured coats. This keeps the wood grain visible and the window frame greys more slowly.

Opaque with Landhuisverf

If you want a coloured window frame, choose Landhuisverf. It is an opaque oil-based paint that keeps the wood structure visible. There are 21 colours, which you can also mix. The paint does not flake or crack, and you can touch it up without sanding.

The sill

Give the sill and the end grain extra attention, because that is where moisture soaks in fastest. Make sure the wood is dry and clean before you start, and always test a colour with a sample first. One litre of UV-Beschermingsolie covers about 18 m² per coat, and one litre of Landhuisverf about 26 m². Rinse used cloths with water afterwards, because cloths with oil on them can self-ignite.

Maintenance

Check window frames every year and touch up bare spots straight away, then you never have to redo the whole frame. Clean with Terrasreiniger and never use a pressure washer. Also see exterior door, and for window frames indoors, see window frame indoors.