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How to Clean and Maintain my PVCu windows
How to Clean and Maintain my PVCu windows
Category: Maintenance & Troubleshooting
Reading Time: 8 Minutes
📌 The Maintenance Summary
- Protect Your Warranty: Neglecting moving parts (hinges/locks) can void your manufacturer warranty.
- No Abrasives: Cream cleaners (like Cif) cause microscopic scratches that make windows yellow and dirty faster.
- Hidden Drainage: Most leaks are caused by blocked drainage slots, not broken seals. Vacuum them out!
- Hampshire Water: Hard water spots need vinegar, not soap, to remove.
Modern PVCu windows are engineering marvels. They keep the heat in, the noise out, and secure your home against intruders. But, like a car, they have moving mechanical parts and seals that degrade if ignored.
This isn’t just about making them look pretty. Proper maintenance prevents expensive repairs. A stiff handle today is a broken gearbox tomorrow. Here is the KJM expert guide to deep cleaning and maintaining your windows.
Table of Contents
1. The Chemistry of Cleaning (Frames)
PVCu frames have a glossy “skin” that is designed to repel dirt. The biggest mistake homeowners make is using the wrong chemicals.
⚠️ The “Cif” Danger
Never use abrasive cream cleaners (like Cif/Jif) or scouring pads.
These products contain micro-granules. While they remove dirt quickly, they also sand off the glossy top layer of the plastic. This leaves a rough, porous surface that holds onto dirt. Once you scrub a window with Cif, it will get dirty twice as fast forever after.
Use This Instead: Warm soapy water (washing up liquid) is usually enough. For stubborn grime, use a specialist Solvent-Free PVCu Cleaner from a trade counter.
2. Glass Perfection (Hard Water & Vinegar)
Living in Hampshire means dealing with hard water. If you wash your windows with tap water on a sunny day, you are often left with stubborn white spots (limescale) that glass cleaner won’t touch.
3. The “Hidden” Drainage System
90% of “leaking window” calls we receive are actually just blocked drainage.
Open your window and look at the bottom of the frame (the rebate). You will see slots or holes. These are Drainage Channels. They are designed to let any water that gets past the first seal run out of the frame externally.
The Fix: These channels collect dead flies, spiders, and dust. If they block, the water builds up and spills inside your house. Vacuum these out twice a year to prevent leaks.
4. Rubber Care & Mould Wars
The black rubber seals (gaskets) around your window stop the wind. Over time, they can gather black mould, especially in bathrooms.
The Bleach Trick: If warm soapy water doesn’t shift the mould on the silicone, soak a cotton wool pad in bleach and leave it pressed against the mouldy seal for 2 hours. The mould will often vanish.
Conditioning: Do NOT use oil or WD40 on rubber gaskets as it causes them to perish. Use a Silicone Spray to keep them supple.
5. Lubrication: The DIY Service
If a handle is stiff, forcing it will eventually snap the internal gearbox. A quick oiling takes 5 minutes and saves you a £150 repair bill.
6. Foiled vs. White Frames
Woodgrain (foiled) windows are structurally different from smooth white plastic. They have a textured laminate skin.
🛠️ Pro Tip: The “WD40 Trick” (Foiled Only)
Over time, foiled windows (like Rosewood or Anthracite Grey) can look dull due to oxidation.
The Fix: Clean the frame with soapy water and dry it. Then, spray a small amount of WD40 onto a cloth and wipe down the frame. It acts like a polish, restoring the deep colour and adding a protective layer against the rain. (Note: Do not do this on white frames, as it can attract dust).
7. Troubleshooting Common Issues
Old PVCu (from the 80s/90s) wasn’t UV stabilized and yellows naturally. This is chemical degradation and cannot be cleaned off. Modern PVC is UV stabilized. If your modern frames are yellow, it might be nicotine or atmospheric dirt—try a specialist “UPVC Restorer” cream.
The spindle inside the handle or the gearbox has failed. Do not force it. This requires a replacement part. KJM offers a full repair service for this issue.
If the mist is inside the sealed unit (you can’t wipe it off), the seal has failed. No amount of cleaning will fix this. The glass unit needs replacing (though you can usually keep the frames).
📚 Related Maintenance Guides
Mark Pearce is a highly experienced specialist in the double glazing industry, having built his knowledge from the ground up through hands-on experience in installation, manufacturing, sales, and business management. Beyond his role at KJM, Mark is a keen blogger, writer, and traveller, often sharing insights on the latest innovations in the home improvement industry.
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