Which paint can I use on uPVC?
Which paint can I use on uPVC?
A uPVC-specific paint or an adhesion promoter with an acrylic topcoat — and avoid dark colours, which can distort the frame.
Two things make uPVC awkward. The surface is a low-energy plastic with plasticiser migrating slowly to it, so ordinary paint has nothing to bond to and lifts at the first knock — which is why every workable system starts with a solvent wipe and either an etching solvent or an adhesion promoter. The second is heat: a dark colour on a white frame can raise the surface temperature by tens of degrees in summer sun, and uPVC has a high coefficient of thermal expansion and softens well below the temperature a dark surface can reach, so frames can bow and seals can fail. Manufacturers commonly state that painting voids the frame guarantee, and that is worth checking before starting rather than after.
The options, ranked
| Option | Good at | Bad at |
|---|---|---|
| uPVC-specific paint system | Solvent-wipe preparation with no sanding required, and formulated to flex with the frame. | Brand-specific systems, limited colours, and a real cost for the amount covered. |
| Adhesion promoter plus acrylic | Cheaper, and lets you use any colour. | More preparation, and the promoter has a strict recoat window. |
| Professional spray refurbishment | Even finish over frames and beading with no brush marks, done in place. | Costly, and requires extensive masking of glass and walls. |
| Replacement or foiled trim | Permanent, guaranteed and colourfast. | By far the most expensive option. |
Technique that changes the outcome
- Clean thoroughly with detergent, then wipe with the solvent the paint system specifies
- Mask the glass and seals properly; overspray on glass is far harder to remove than it looks
- Apply thin coats within the stated recoat window
- Choose light colours, particularly on south-facing frames
- Check the window guarantee before painting
What goes wrong
- Ordinary gloss or emulsion straight onto uPVC
- Dark colours on frames in full sun
- Painting over the rubber gaskets, which then stick and tear when the window is opened
Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here.
Other paint questions
| For | Use |
|---|---|
| Previously painted wood | Clean it, key it and spot-prime bare areas — and find out first whether the existing paint is oil or water based. |
| Bare wood | Knotting solution on the knots, a wood primer, then your topcoat — and prime end grain twice. |
| Plastic | Any paint, provided an adhesion promoter goes on first — and on polypropylene or polyethylene, the promoter is not optional. |
| Kitchens | A scrubbable acrylic eggshell or satin on the walls — and for cabinets, degrease, prime and use a proper cabinet enamel. |
| Bathrooms | A moisture-resistant acrylic in a satin or eggshell sheen with a mould inhibitor — but ventilation, not paint, is the actual fix. |
| Metal | Remove the rust, apply a rust-inhibiting primer the same day, then an alkyd or a direct-to-metal acrylic. |
| Ceilings | A flat matt emulsion — and if there is a water stain or nicotine, seal it with a shellac-based stain block first. |
| Tiles | Tile paint over an epoxy or adhesion primer on a thoroughly degreased and abraded glaze — and expect a limited life in a shower. |
| Fences | A penetrating stain or fence treatment rather than a film-forming paint — and let new pressure-treated timber weather first. |
| Floors | Two-pack epoxy on concrete after a moisture test and a proper grind; floor-grade varnish or floor paint on timber. |
| Radiators | A radiator enamel — water-based acrylic ones no longer yellow, which ordinary gloss on a hot surface always will. |
| Exterior masonry | A breathable mineral or masonry paint — and on an old solid wall, breathability matters more than any durability claim. |
| Galvanised metal | A mordant wash, a self-etch primer or a purpose-made acrylic primer for galvanising — ordinary oil-based primer peels off in sheets. |
Common questions
- Which paint can I use on uPVC?
- A uPVC-specific paint or an adhesion promoter with an acrylic topcoat — and avoid dark colours, which can distort the frame.
- What should I avoid?
- Ordinary gloss or emulsion straight onto uPVC Dark colours on frames in full sun Painting over the rubber gaskets, which then stick and tear when the window is opened
Related pages
- Which paint goes over previously painted wood? Clean it, key it and spot-prime bare areas — and find out first whether the existing paint is oil or water based.
- Which paint should I use on bare wood? Knotting solution on the knots, a wood primer, then your topcoat — and prime end grain twice.
- Which paint sticks to plastic? Any paint, provided an adhesion promoter goes on first — and on polypropylene or polyethylene, the promoter is not optional.
- Which paint should I use in a kitchen? A scrubbable acrylic eggshell or satin on the walls — and for cabinets, degrease, prime and use a proper cabinet enamel.
- Which paint should I use in a bathroom? A moisture-resistant acrylic in a satin or eggshell sheen with a mould inhibitor — but ventilation, not paint, is the actual fix.
- Which paint should I use on metal? Remove the rust, apply a rust-inhibiting primer the same day, then an alkyd or a direct-to-metal acrylic.
- Which paint should I use on a ceiling? A flat matt emulsion — and if there is a water stain or nicotine, seal it with a shellac-based stain block first.
- Which paint can I use on tiles? Tile paint over an epoxy or adhesion primer on a thoroughly degreased and abraded glaze — and expect a limited life in a shower.
- Which paint should I use on a fence? A penetrating stain or fence treatment rather than a film-forming paint — and let new pressure-treated timber weather first.
- Which paint should I use on a floor? Two-pack epoxy on concrete after a moisture test and a proper grind; floor-grade varnish or floor paint on timber.
Sources
- Typical range compiled from manufacturer specifications — At One Place