How to clean uPVC window frames and keep them white

The safest way to clean uPVC window frames is with warm water, a little washing-up liquid and a soft microfibre cloth. Wipe the frames down, work into the corners and seals with an old toothbrush, then dry with a clean cloth. Avoid abrasive scourers, scouring cream and bleach, which scratch the surface and can leave uPVC looking yellow or grey over time.

Why uPVC frames go grey or yellow

uPVC discolours for two reasons: a build-up of dirt, pollution and algae on the surface, and longer-term yellowing from UV exposure and harsh cleaning. Surface grime cleans off easily if you stay on top of it. The grey, ingrained look that builds up over years is much harder to reverse, which is why regular cleaning matters more than any miracle product.

What you should not use on uPVC

• Abrasive pads and scouring cream: they scratch the finish, and scratches trap dirt and dull the surface permanently.
• Bleach and strong solvents: they can discolour and dry out the plastic and damage rubber seals.
• Washing-up sponges with a scratchy side: use the soft side only, or a microfibre cloth.

The simple step-by-step method

Start with the gentlest approach and only step up if needed.

• Brush or vacuum loose dirt from the frame and the channel the window sits in.
• Wash the frame with warm soapy water and a soft cloth, top to bottom.
• Use an old toothbrush for corners, beading and textured areas.
• Rinse with clean water and dry with a microfibre cloth to avoid streaks.

For light marks, a dedicated uPVC cleaner or cream specifically labelled as non-abrasive can help. Always test on a hidden corner first.

Do not forget the seals, hinges and drainage holes

The rubber seals keep your windows weatherproof, wipe them gently and avoid solvents that dry them out. A dab of light oil keeps hinges and locks moving. At the bottom of the frame are small drainage slots that let rainwater escape; clear these with a cotton bud or toothbrush so they do not block and cause damp on the sill.

How often should you clean uPVC frames?

Two to four times a year keeps frames white and prevents ingrained grime. Homes near busy roads, trees or the coast may need it more often. Cleaning the frames at the same time as the glass gives the best overall result, our guide to how often to clean windows has a full schedule.

Letting the professionals handle it

Cleaning ground-floor frames is straightforward, but upper-floor windows, frames and seals are awkward and risky to reach. Professional window cleaning covers the glass, frames and sills together using reach-and-wash systems, so the whole window looks its best without ladders. If your frames have gone grey despite regular cleaning, a professional can advise whether they can be restored or simply need more frequent care.