Can a roof window be painted?

Internal timber: yes

Most timber framed roof windows are supplied lacquered or factory painted, and both can be recoated. Over twenty years a lacquered frame will darken and the finish at the bottom of the sash, where condensation runs, will start to break down.

Recoating a sound frame is straightforward and much cheaper than replacement.

Preparation matters more than paint. Clean thoroughly, sand back any failed finish to sound timber, treat any dark staining, and prime bare wood. Mask the glass, the seals and the hinges: paint on a gasket stops it sealing, and paint in a hinge stiffens the action.

Use a water based satin or eggshell for interior joinery. It stays flexible and does not yellow the way old oil based paints did.

External cladding: no, effectively

The outside of a roof window is aluminium cladding, factory coated, and it is there to take the weather. Painting it on site rarely lasts: adhesion to a factory coating is poor and the finish fails within a few seasons, usually at the edges.

It is also exposed to UV and, on this coast, salt. A site applied coating is not going to survive that.

Where the external colour matters, order the cladding in the colour you want. Most manufacturers offer several, and it costs far less than a repaint that will fail.

Polyurethane frames

The white bathroom-suitable frames are a moulded finish rather than a coating. They can be painted with the right primer, though people rarely want to: the point of them is that they need nothing.

Listed buildings

Where a property is listed, changing the colour of a window may itself need consent. Worth checking before starting.

Usually yes on timber, no on the cladding

Most roof windows are laminated timber internally with an aluminium or plastic cladding externally. Those two halves behave completely differently.

The internal timber

Can be painted or stained, and frequently should be. Factory finishes are either a clear lacquer or a white paint, and both can be overcoated once the surface is properly prepared.

Clean it, key the existing finish with a fine abrasive, and use a paint suitable for interior joinery. Where the frame is bare or the finish has failed, it needs sealing properly, because bare timber in a rooflight reveal will absorb moisture from condensation.

Do not paint over the gaskets, the hinges, the handle mechanism or the ventilation flap and filter. Paint in a gasket stops the sash seating, which lets water past and gets reported as a leak.

The external cladding

Factory finished aluminium, and it should be left alone. It is a durable coating applied under controlled conditions, and painting over it on site gives you a finish that will not last and that voids any manufacturer warranty on the cladding.

Where the external colour matters, most manufacturers offer alternative cladding colours at the point of order. That is the time to decide.

Steel conservation units

Powder coated at the factory in matt black or a dark colour, and they do not need painting. Where the coating is damaged, touch up rather than repaint, because exposed steel corrodes.

On a coastal or exposed site, check the coating every few years.

Uncoated or older timber windows

Older units, particularly pre 1990s, are sometimes bare or varnished timber inside and out. Those do need maintaining, and the exterior needs a proper exterior system rather than an interior paint.

Where the exterior timber of an old window has weathered badly, painting is a holding measure. Decayed timber means replacing the window rather than coating it.

Before you paint

Open the sash fully and prop it, mask the gaskets and the glass edge, and let it dry fully before closing. A sash closed onto tacky paint sticks to its gasket and tears it.

The mistakes we get called to

Paint in the gasket, which is the commonest. A sash closed onto a painted or tacky compression seal does not seat properly, water gets past, and it is reported as a leak months later. Mask the gaskets before you start and let everything dry fully before closing the window.

Paint in the ventilation flap and filter, which stops the trickle ventilation working. The room then gets damper and the condensation is blamed on the glass.

Paint over the hinge and handle mechanism, which stiffens the operation and, on a centre pivot unit, can stop it locking in the cleaning position.

And painting the external cladding, which is a factory applied coating that will not take a site finish well and which voids any manufacturer warranty on it.

None of those is catastrophic and all of them are avoidable with masking tape and ten minutes of preparation.

It depends what it is made of

Bare or stained timber, internally. Yes. Clean it, key the surface lightly, prime if the manufacturer recommends it, and use a paint suited to the environment. In a bathroom or kitchen use a moisture tolerant finish.

Factory applied polyurethane or lacquered white finish. Possible but rarely worthwhile. The factory finish is durable and hard, and paint over it will not adhere as well as the original. If you do, degrease and key thoroughly.

Powder coated aluminium or the external cladding. Do not. The coating is the protection, and painting over it traps moisture at the interface and looks poor within a couple of years. Where the colour is wrong, the answer is a manufacturer finish specified at order.

PVCu. Specialist paints exist and results vary. Not recommended on an external face.

What must not be painted

The gasket. Paint on the compression seal stops it recovering after being squeezed, and the window will draught and eventually leak.

The drainage channel at the sill, which paint can partly block.

The glass and any coating on it.

The hinge mechanism and any moving part.

Masking those properly is most of the work, and rushing it is how a decorating job becomes a repair.

The warranty point

Repainting a factory finished unit may affect the manufacturer warranty. Worth checking before rather than after, particularly on a window still within its term.

The maintenance angle

A painted timber window in a bathroom needs its finish renewed on a far shorter cycle than one on a landing, and catching it before the finish fails is the whole point. Once water reaches bare timber it is a different job.