Yes. Both can be painted with a specialist exterior paint formulated for non-porous surfaces, and the result lasts years when the preparation is done properly. Two things decide whether it is a good idea: whether your door is still under a surface warranty, and whether you are going darker than the colour it was made in.
We manufacture doors, so telling you to buy a new one instead of painting the one you have would serve us rather than you. Worth saying openly before the rest of the article.
Painting works. On a door that is sound, moves properly and simply looks tired or dated, a good paint job is the cheapest sensible answer and it will hold for years.
Painting is the wrong answer in three situations, and none of them is about the paint. If the leaf has bowed, if the hinges have play in them, or if the seals have gone hard and shiny, paint covers a fault instead of fixing it. If the door drags or resists locking, our adjustment guide is the place to start, and paint can follow once it works.
Everything below assumes the door is mechanically sound and you have decided to change its colour.
Going darker than the original colour carries a risk that going lighter does not. A dark surface absorbs considerably more solar energy than a white one, and uPVC softens as it heats. The result, on a door that gets strong afternoon sun, can be a leaf that bows enough to stop sealing.
This is the part the DIY guides skip, and it deserves explaining properly. Factory-coloured and foil-wrapped uPVC is not just white uPVC with colour on it. Dark profiles are specified for the heat load they will carry, using formulations and reinforcement suited to it. A white profile was specified on the assumption that it would stay white.
That does not make painting a white door dark impossible. It makes the elevation the deciding factor.
If your door faces the sun and you want anthracite grey, a factory-finished door in that colour is the route that carries a warranty rather than a risk. Anthracite has been the most requested colour in the UK for years, and it is available as a manufactured finish precisely because so many people want it.
A composite door can be painted, and it is harder than painting uPVC. The outer skin is glass-reinforced plastic, moulded with a woodgrain texture, and both properties work against you.
GRP is non-porous and chemically resistant, which is exactly what makes it a good door skin and a poor substrate. It needs a primer rated for GRP or fibreglass, not a general multi-surface primer, and the manufacturer's own instructions matter more than any general guide.
The woodgrain texture is the second problem. Paint pools in the grain and thins on the raised surface, so a brushed finish looks uneven in daylight even when it looked fine while wet. Spraying handles this far better than brushing, which is why most good results on composite doors are sprayed rather than rolled.
Worth remembering what the colour on a composite door actually is. It runs through the GRP rather than sitting on it, which is why the door never needed painting in the first place. You are covering a surface engineered not to be covered, and the finish you apply will need maintaining on a cycle in a way the original did not.
Standard household gloss and oil-based paint fail on both materials, because neither surface is porous and neither gives conventional paint anything to grip.
What works is an exterior paint formulated for plastics and non-porous surfaces. Acrylic, solvent or resin-based specialist coatings are the usual categories, and several major brands make multi-surface exterior products suited to the job. Some are self-priming; others need a separate adhesion primer.
Two rules regardless of product. Follow the paint manufacturer's system rather than mixing brands between primer and topcoat, because adhesion failures usually happen at that join. And test on a hidden area first, particularly on foil, where adhesion varies with the foil's age and condition.
That last step catches people out. Paint that feels dry to the touch is not cured, and a door closed too early sticks to its own seals and pulls the finish off when you open it.
Preparation is where paint jobs are won. Most failures traced back to a surface that was not clean enough, not keyed enough, or not dry when the primer went on.
Five parts of a door should stay unpainted, and this list matters more than anything about colour.
Mask all five before you open a tin. A door that seals worse and locks worse than before is a bad outcome from a job that went well cosmetically.
Painting is one of four routes, and the right one depends on the condition of the door rather than your budget.
Vinyl wrapping deserves more attention than it gets. A wrap applied by a competent fitter gives a finish closer to a factory colour than a brushed paint job, and it does not carry the heat absorption question in the same way a dark paint layer does, because the films used are made for exterior profile.
If the door needs replacing anyway, ordering it in the colour you want removes the whole question. Our colour options cover factory finishes across uPVC, timber and alu-clad.
