Cleaning window frames: how to clean uPVC and foiled frames properly
Grey film, adhesive residue from protective film, plaster or paint splashes: this is how to clean uPVC windows and frames foiled with RENOLIT or Continental thoroughly without damaging the surface – and how to tell when cleaning no longer helps.
In short
- For regular cleaning, lukewarm water, a little washing-up liquid and a soft microfibre cloth are all you need.
- Clean at least twice a year, in spring and autumn.
- Never use: scouring agents, magic erasers, acetone, cellulose thinner, white spirit or metal blades.
- If the plastic itself has yellowed, cleaning will not make it white again. What helps is a new surface, for example the white window frame foil in traffic white.
Cleaning uPVC windows in 4 steps
Ideally on a cloudy day: in direct sunlight the water dries too quickly and leaves streaks.
Remove loose dirt
Brush or vacuum dust, sand and insects out of the rebates and drainage slots. Wiping dry rubs the grit across the surface.
Soak and wipe
Soak the frame with lukewarm water and a little washing-up liquid, then wipe with a soft cloth or a sponge without a scouring side.
Rinse and dry
Wipe again with clean water so that no detergent residue attracts dirt, then dry with a microfibre cloth.
Seals and fittings
Wipe seals with water only. Do not flood the fittings with soapy water.
Toilet paper trick: dampen toilet paper slightly with a spray bottle, lay it on the frame – it sticks by itself – and spray it with soapy water. The paper keeps the moisture on the surface, so the dirt soaks much longer. Keep spraying, then remove the paper and wipe clean.
Getting window frames white again
First find out whether it is dirt or yellowing. Grey film, soot or pollen sit on the surface. A yellowish discolouration of old frames is in the plastic, usually caused by years of UV exposure.
It is dirt
Soak longer and repeat several times instead of rubbing harder. For stubborn grey film, use a plastic cleaner without solvents and without abrasives.
It is yellowing
Scouring cream or magic erasers remove the surface. The frame looks lighter for a short time, but becomes rough and gets dirty faster afterwards. It only stays white with a new surface made of self-adhesive foil in traffic white – our guide wrapping window frames shows how.
White window frame foil in traffic white
Self-adhesive exterior foil by Continental (formerly Hornschuch) for white uPVC windows. It is applied directly to the cleaned frame – the window stays in place. Available in widths of 100, 180, 200, 500 and 1000 mm.
- Tip: order a foil sample for €0.99 first and compare the shade of white on your frame
- Free sample shipping
Removing adhesive residue from window frames
Adhesive residue usually comes from the protective film on new windows. If it is peeled off too late, or in strong sun or frost, the adhesive stays on the frame.
- Remove the protective film as soon as possible after installation.
- Warm cold, hard residue with a hair dryer on the lowest setting.
- Soak light residue with warm soapy water and wipe off with a soft cloth.
- Remove stubborn residue with the RENOLIT window frame cleaner – test on an inconspicuous area first.
Do not use
Knives, cutters or glass scrapers with metal blades, and solvents such as acetone or cellulose thinner. They leave permanent scratches or dull patches – on foiled frames these cannot be polished out.
Heavily soiled frames
Patience beats pressure: soak well – ideally with the toilet paper trick from step 2 – work with plenty of water and rinse loosened particles off thoroughly, otherwise they act like sandpaper. Clean woodgrain foils with a soft brush in the direction of the grain.
Paint, plaster and building dirt
Tile adhesive, paint and plaster splashes, rubber marks and crayon often come off with hot tap water and washing-up liquid. For dried-on residue, use the cleaner from the foil manufacturer.
What is safe on window frames?
| Product | White uPVC | Foiled frame | Note |
|---|---|---|---|
| Water + washing-up liquid | suitable | suitable | standard for regular cleaning |
| RENOLIT window frame cleaner | suitable | suitable | non-solvent, for adhesive residue, rubber marks, crayon, building dirt |
| Vinegar solution | well diluted | well diluted | keep away from seals, rinse with clean water |
| Magic eraser (melamine sponge) | test first | do not use | acts like fine sandpaper, makes the surface dull |
| Scouring cream, baking soda, toothpaste | do not use | do not use | abrade the surface |
| Acetone, cellulose thinner, white spirit | do not use | do not use | attack plastic and foil |
| WD-40 | not recommended | do not use | leaves an oily film that collects new dirt |
Cleaners for uPVC and foil
Window frame cleaner for foiled surfaces
Developed by the foil manufacturer for RENOLIT EXOFOL: degreasing, antistatic, non-solvent. For adhesive residue, rubber marks, crayon and building dirt.
uPVC window frame cleaner, non-solvent
For regular cleaning of white and foiled uPVC windows.
Video: removing building dirt from window frames
FAQ: cleaning window frames
How often should you clean window frames?
At least twice a year, in spring and autumn. More often near busy roads or kitchens.
How do I get yellowed uPVC windows white again?
Real yellowing is in the material and cannot be cleaned off. With self-adhesive window frame foil in traffic white, the frame gets a new surface without replacing the window. Compare the shade with a €0.99 foil sample first.
How do I get heavily soiled window frames clean?
With patience instead of pressure: dampen toilet paper, lay it on the frame and keep spraying it with soapy water. This lets the dirt soak for a long time, so it can be wiped off without scrubbing. Remove stubborn residue with a non-solvent cleaner.
Can I use WD-40 on uPVC windows?
Not for cleaning. It leaves an oily film on which new dust quickly collects. It should not be used on foiled frames at all.
Can I use a magic eraser?
Not on foiled frames – it abrades the surface. On white uPVC only after testing on an inconspicuous area, as the surface may look dull afterwards.
How do I clean foiled window frames properly?
Like white uPVC, only more gently: water, washing-up liquid, a soft cloth and a soft brush for woodgrain foils. For stubborn dirt, use a non-solvent cleaner from the foil manufacturer.
A new surface instead of scrubbing
If the frame stays yellow after cleaning or the old foil is damaged, self-adhesive foil by RENOLIT or Continental gives it a new surface – in over 250 decors, without replacing the windows.