How to paint exterior doors, windows and metalwork

A fresh coat of paint can make a remarkable difference to your home’s exterior, whether you’re updating a front door, refreshing window frames or restoring painted metalwork.

For a beautiful, lasting finish, preparation is just as important as the paint itself. From choosing the right conditions to priming different surfaces, here’s our guide to painting exterior woodwork and metalwork.

Before you start: choosing the right paint and conditions

A little planning will help you achieve the best possible result.

Choose your paint finish

For exterior woodwork and suitable metal surfaces, our Water-Based Eggshell offers a satin finish with approximately 20% sheen, while our Water-Based Gloss provides a higher-shine finish of approximately 80%.

Always check the relevant technical data sheet to confirm suitability for your surface and application.

Check the weather

Choose a dry, mild day, avoiding rain, frost, extreme heat and strong direct sunlight. Allow enough time for each coat to dry before temperatures fall or moisture develops.

Where possible, work on the shaded side of the building to prevent the paint from drying too quickly.

Test your colour

Exterior colours can look very different in natural daylight, so it’s worth testing your chosen shade before committing.

Our A5 colour cards and sample pots can help you compare colours alongside existing brickwork, stone and architectural details.

How to prepare and paint exterior woodwork

Good preparation is essential for a smooth, durable finish on exterior doors, window frames and other timber surfaces.

Painting bare wood

1. Ensure the timber is clean, sound and completely dry. Remove any dust, dirt or loose material.
2. Prepare the surface by sanding where necessary, then remove all sanding dust.
3. Prime bare timber with our Water-Based Wood Primer, following the product instructions for any knots or areas requiring additional preparation.
4. Allow the primer to dry thoroughly, then lightly sand and remove the dust.
5. Apply at least two coats of the appropriate exterior paint finish, allowing each coat to dry fully. Lightly sanding between coats can help achieve a smoother result.

Painting previously painted wood

If the existing coating is sound, clean and sand the surface thoroughly to provide a suitable key for the new paint.

Remove any loose or flaking paint and repair damaged areas before decorating. Bare patches may require priming.

Apply at least two coats of your chosen finish, following the recommended drying and recoating times.

How to prepare and paint exterior metalwork

Exterior metalwork requires particular attention to surface preparation, especially where rust is present.

Painting bare iron or steel

1. Clean the surface thoroughly, removing dirt, loose material and corrosion.
2. Sand or abrade the metal to prepare it for painting.
3. Apply a suitable rust-protection primer, following the manufacturer’s instructions.
4. Allow the primer to dry completely before applying the recommended paint finish.
5. Apply the required topcoats, observing the drying and recoating times stated in the technical data sheet.

Painting previously primed metal

For factory-primed ferrous metal in sound condition, clean and sand the surface thoroughly before painting.

Depending on the existing primer and the paint system being used, further preparation or priming may be necessary.

Important: Not all paints and primers are suitable for every metal. Galvanised steel, aluminium and other non-ferrous metals may require specialist products, so always check compatibility before starting.

Choosing exterior paint colours for doors and windows

Colour can make a striking difference to the appearance of your home, whether you’re restoring traditional joinery or introducing a contrasting shade to a front door.

White remains a classic choice for exterior woodwork, particularly against brick and natural stone. Softer off-whites can offer a gentler contrast, while deeper greens, blues and earthy shades can highlight architectural details.

For a more individual approach, consider our exterior colours developed with garden designer Pollyanna Wilkinson, including Helleborus, Thicket and Shadow.

When choosing a colour, consider the surrounding materials, the age and character of your property, and how the shade appears in different daylight conditions.

Our Colour Consultants can help you find a scheme that complements your home’s exterior.

Can you use the same paint on garden furniture?

Some exterior woodwork paints may also be suitable for garden benches, chairs and other painted timber features, provided the product is approved for the intended surface and exposure conditions.

Garden furniture often experiences additional wear, moisture and weathering, so always check the technical guidance before painting.

Check the technical guidance before painting

The right preparation and application method will depend on your surface, the existing coating and the finish you choose.

For detailed information about surface preparation, compatible primers, drying times and application conditions, please consult our technical data sheets.

With the right preparation, a carefully chosen colour and an appropriate paint finish, exterior doors, windows and metalwork can become some of the most appealing features of your home.