How to Repaint a Wooden Window: Preparation and a Successful Finish

A wooden window whose paint is flaking, greying or peeling is both unsightly and dangerous for the wood: without protection, rain seeps in and rots the frame. Repainting a wooden window is a perfectly accessible job, but it requires patience. The quality of the result depends 80 % on the preparation: it is by taking care of it that you will get a durable, clean finish.

The materials you need

• Sander or abrasive paper of different grits (coarse for stripping, fine for smoothing).
• Filling knife and wood filler or filling compound to fill the holes and cracks.
• Special wood primer to guarantee the paint's adhesion.
• Suitable exterior wood paint: alkyd or acrylic, matt, satin or gloss depending on your taste.
• Good quality brushes: a round brush for the small hollows and a flat brush for the surfaces.
• Masking tape and a drop cloth to protect the glass and the frame.
• Gloves and glasses, and a clean cloth to dust off.

Preparation: the most important step

1. Remove the hardware (handles, espagnolettes) or mask it carefully with tape.
2. Sand the surface to remove the flakes of paint and smooth the wood: work dry or with wet sanding, depending on the condition of the surface.
3. Fill the holes, cracks and screw holes with wood filler, then sand again once dry for a perfectly flat surface.
4. Dust the whole frame with a cloth or soft brush: the slightest dust creates visible ridges under the paint.
5. Apply the primer over all the bare or sanded wood, leave to dry for the stated time, then sand lightly for a smooth finish.

Painting the window: the technique

Always paint in dry, mild weather, ideally between 10 and 25 °C, and not in full sun. Start with the small surfaces (the inner stiles, the rails) with the round brush, then finish with the flat surfaces. Apply thin coats rather than one thick coat, and wait the drying time stated between coats: two finishing coats are generally needed for a good result.

Alkyd or acrylic: what to choose?

Alkyd paint, solvent-based, remains much appreciated for its gloss, adhesion and resistance, but it takes longer to dry and gives off strong smells: you need to air well and allow longer drying times between coats. Acrylic, water-based, dries faster, is easier to apply and cleans up with water, but it is generally a little less durable long-term outdoors. For a window exposed to the weather, choose a quality exterior wood paint and check that your primer is compatible with the finish selected: certain primers are designed specifically for one or other type of paint.

The mistakes to avoid

• Painting without removing the old flaking paint: the new coat will peel off with the old.
• Skipping the primer on bare wood: the paint will not hold and the wood can mottle.
• Painting too thickly or in hot weather: it causes runs and blisters.
• Closing the windows before complete drying: the paint sticks and the seals mark.
• Neglecting the small cracks in the wood, which let moisture in and spoil the frame within a few seasons.

How much does it cost and how long does it take?

For a standard window, allow half a day to a day of work depending on the condition of the wood, and a budget of 20 to 40 € for the primer, the paint and the consumables: quality wood paint pots generally cost between 20 and 45 € a litre, and one litre covers about 10 to 12 m² per coat, i.e. easily enough for several windows. The longest part is the drying time between coats, which is measured in hours.

When to replace rather than repaint?

If the wood is spongy, deeply cracked or part of the frame has rotted, simple paint is no longer enough: you will need to replace the damaged wood or the whole frame. A professional (carpenter or painter) will be able to tell you whether the frame can be saved. On the other hand, regular maintenance — cleaning, sanding the flakes and touching up every year — keeps windows in good condition for decades.

Repainting a wooden window is a rewarding job that protects your joinery and enhances your facade. The key is rigour: careful preparation, a primer, thin coats applied in fine weather, and above all patience between each step. With this method, you will get a smooth, durable finish, provided you do not rush.