Peel it off as soon as the installation is finished. If it's been left in the sun and has gone brittle, warm it gently with a hairdryer, lift an edge with a plastic scraper and peel slowly at a low angle. Clear leftover glue with a uPVC-safe cleaner, never a metal blade or strong solvent.
Why does the film get stuck?
Sunlight and heat break it down. The protective film on new uPVC frames is meant to come off soon after fitting. Left on for weeks or months, the sun makes the plastic brittle and bonds the glue more firmly to the frame. Instead of peeling off in one strip, it tears into small pieces and leaves sticky patches behind.
South-facing windows suffer most, and the edges of the film, which get the most sun, are usually the worst.
How long can the film stay on?
As short a time as possible. Many window makers recommend removing the film soon after installation. Check your installer's paperwork if you have it. The longer it stays on through a sunny spell, the harder it'll be to take off.
How do you get brittle film off?
Warm it, lift it, peel it slowly. Use a hairdryer on a low or medium setting to warm a small section, which softens both the film and the glue. Lift an edge with a plastic scraper or an old plastic card, then peel back at a low angle, slowly, keeping it warm as you go.
- Work in small sections.
- Keep the hairdryer moving so the frame doesn't get too hot.
- Peel low and slow, not straight up.
- Use plastic tools, never metal.
How do you get the leftover glue off?
With a cleaner made for uPVC and a soft cloth. Leftover glue picks up dirt fast, so it shows as grey patches. Most uPVC cleaners will soften it enough to wipe off with patience. Washing-up liquid and warm water help with small amounts.
Some people reach for strong solvents. Be careful: some can soften or dull the surface of uPVC and leave a patch that never quite matches the rest of the frame. Test anything new on a hidden area first.
What should you avoid?
- Metal blades and scrapers: they gouge uPVC.
- Scouring pads: they leave a dull, scratched patch.
- Heat guns: they can warp or mark frames. A hairdryer is enough.
- Strong solvents: they can damage the frame's finish and the seals.
What about film on the glass?
Some new windows and doors also come with stickers or film on the glass. These come off more easily: soak them, then lift with a fingernail or plastic card. Any leftover glue usually comes off with a little washing-up liquid. On ordinary glass, a wet new blade pushed forward can lift sticky marks; on toughened glass, stick to soaking and soft pads.
Should you clean the windows at the same time?
Yes. Once the film is off, the frames, glass and sills will have builders' dust and grit around them. Rinse first with plenty of water so you don't drag grit across the new glass. Our guide on getting cement and mortar off windows covers the rest of the first clean.
When should you get help?
When there are lots of frames, when they're upstairs, or when the film has baked on badly. Removing it is slow work. Our after-builders window clean takes off film, glue and grit and leaves the frames and glass clean, across Essex.