uPVC window maintenance gets put off because the frames never need painting. What wears out are the steel parts hidden in the edge of the frame: the friction hinges, the locking gear and the keeps it latches into. Left dry for a few winters, they grind, the handle needs both hands and the window stops closing tight. Fifteen minutes per window, twice a year, prevents all of that.
Last checked: November 2026
The short version: wash the frame with warm soapy water, brush the grit out of the hinge tracks and clear the drainage slots. Then put one drop of Ballistol Universal Oil on each hinge pivot and locking cam, open and close the window five or six times and wipe off the excess. Keep oil off the rubber seals and do it every spring and autumn.
| Quick facts | |
|---|---|
| Time needed | About 15 minutes per window, 5 of them for oiling |
| You'll need | Warm water with a little washing-up liquid, a soft cloth, an old toothbrush, a pipe cleaner, kitchen roll and Ballistol Universal Oil (the 350ml VarioFlex has a bendy straw, the 50ml bottle suits drop-by-drop work) |
| How much oil | One drop per pivot, cam and keep, roughly 1 to 2ml for a whole window |
| How often | Every spring and autumn, every 3 months within a mile or so of the sea |
| Avoid | Oil on the rubber seals or glass, abrasive cream cleaners, scouring pads, thick grease in the hinge track |
In this guide
- What does uPVC window maintenance involve?
- Which parts of a uPVC window need oil?
- How to lubricate uPVC window hinges and locks
- Why is my uPVC window handle stiff?
- How do you clear uPVC window drainage holes?
- What should you keep off uPVC frames and seals?
- When should you service uPVC windows?
- Signs your windows need doing again
- Questions people ask
What does uPVC window maintenance involve?
uPVC window maintenance comes down to four jobs: washing the frames, clearing the drainage slots, checking the rubber seals and lubricating the hinges and locking mechanism.
Most uPVC casement windows in UK homes open on friction stays, the flat steel arms you see with the window open. Turning the handle slides a bar along the sash edge that pushes small mushroom-shaped cams into steel keeps on the frame.
Which parts of a uPVC window need oil?
On a uPVC window, oil goes on the moving metal only: the pivot rivets and sliding shoe of each friction hinge, the locking cams along the sash edge, the keeps on the frame and the keyhole of a locking handle. The plastic frame, the glass and the rubber seals need cleaning, not oil.
Ballistol, which F.W. Klever GmbH has made in Germany since 1904, creeps into very fine gaps, leaves a thin film against corrosion and does not go sticky, which matters in a hinge track that collects dust all summer.
| Which product for which job | Product | Why |
|---|---|---|
| Friction hinges, locking cams, keeps, handle locks | Ballistol Universal Oil | Creeps into pivots and fine gaps, lubricates and protects the steel against damp |
| Sliding patio door rollers and tracks | Ballistol PTFE Spray | Leaves a dry film that does not pick up dust and grit from the track |
| Rubber seals, frames and glass | Warm soapy water and a soft cloth | These need cleaning only; keep oil off the seals |
How to lubricate uPVC window hinges and locks
To lubricate uPVC window hinges, open the window fully, clean the grit out of the hinge track first, then put a drop of oil on each pivot and on the locking cams. Work the window and handle a few times so the oil spreads, and wipe off what's left.
- Open the window fully and make sure it can't swing shut on your fingers.
- Brush the grit out of the hinge tracks with an old toothbrush or a vacuum nozzle.
- Wipe the hinge arms, sash edge and keeps with a damp soapy cloth and let them dry.
- Put one drop of Ballistol Universal Oil on each pivot rivet of the hinge and one along the track where the sliding shoe runs. With the VarioFlex, a quick burst of under a second through the straw is enough.
- Put a drop on each locking cam along the sash edge and on each keep on the frame. A typical window has three to six.
- Open and close the window five or six times and turn the handle through its full travel.
- Wipe off the excess with kitchen roll and check nothing has run onto the seals.
A friction hinge needs some friction to hold the window open. If it drifts in the wind after oiling, wipe the track dry. Some friction stays have an adjusting screw on the sliding shoe; turn it a quarter turn at a time.
Why is my uPVC window handle stiff?
A stiff uPVC window handle is usually caused by dry, dirty locking cams and keeps, or by the sash sitting slightly out of line, so the cams drag on the keeps as the handle turns. Cleaning and oiling the cams and keeps fixes the first cause in a few minutes.
Turn the handle with the window open. If it moves easily open but fights you shut, the cams are catching on the keeps: oil them as above. If it stays tight, the sash has probably dropped or a keep has moved, which is a job for a window repairer. Forcing the handle can break the gearbox inside the sash.
How do you clear uPVC window drainage holes?
uPVC window drainage holes are the small slots in the bottom of the outer frame, usually under a hinged cap on the outside. Clear them with a pipe cleaner or a thin brush, then pour a small cup of water along the bottom rail and check it runs out within a minute.
Blocked slots let rainwater sit in the frame and freeze against the bottom keeps in a cold snap. Don't force a screwdriver in, as some slots have a baffle behind them.
What should you keep off uPVC frames and seals?
Keep abrasive cleaners, scouring pads, bleach and solvents off uPVC frames, and keep oil off the rubber seals. Abrasives dull white uPVC and wear through coloured foil, and many window seals are rubber that oil can soften.
Ballistol Universal Oil suits oil-resistant plastics and rubber, but window gaskets vary, so just wash them and wipe off any oil that lands on them. On coloured or foiled frames, try any cleaner on a hidden spot first. There is more on materials in is Ballistol safe on plastic, rubber and paint, and the safety data sheets are on our technical data page.
When should you service uPVC windows?
Service uPVC windows twice a year, in spring and again in October or November before the first frosts. Within a mile or so of the coast, do the hinges every 3 months, because salt air marks even stainless hinges.
The autumn visit matters most. Damp, condensation and frost all work on the hinges and keeps, and a window that only just closes in September can refuse to latch in January. Do the doors and padlocks the same day; our guide on how to unfreeze a frozen lock covers those, and squeaky hinges, stiff locks and sliding doors covers the rest of the house.
Fire escape windows deserve a check every time. Building Regulations guidance for homes in England, Approved Document B (fire safety), expects an escape window to give a clear opening of at least 0.33 square metres, at least 450mm high and 450mm wide. Make sure escape hinges still swing fully open.
Signs your windows need doing again
A well-maintained uPVC window closes with light pressure from one hand, the handle turns smoothly through its full travel and nothing squeaks or grinds. There should be no draught along the opening edge.
Repeat the job when a hinge squeaks, the handle needs more effort, a cam scrapes into its keep or rust spots appear. Water standing on the bottom rail after rain means the drainage slots need clearing.
Questions people ask
What is the best lubricant for uPVC window hinges? The best lubricant for uPVC window hinges is a light oil that creeps into the pivots and does not go sticky, such as Ballistol Universal Oil. Thick grease holds grit in the track.
Why is my double glazed window hard to close? A double glazed window is usually hard to close because the locking cams are dry and catching on the keeps, or the sash has dropped on its hinges. Clean and oil the cams and keeps first; if it still drags, get the hinges adjusted.
Should you oil uPVC window seals? No, uPVC window seals should be cleaned with warm soapy water, not oiled. Many window seals are rubber that oil can soften, so wipe off any oil that lands on them.
How do you adjust uPVC window hinges? Some uPVC friction hinges have an adjusting screw on the sliding shoe that sets how firmly the window holds its position. Turn it a quarter turn at a time, and leave a dropped sash to a window repairer.
How often should uPVC windows be serviced? uPVC windows should be cleaned and have their hinges and locks oiled twice a year, in spring and autumn, or every 3 months near the coast.
At one or two millilitres a window, a small bottle of Ballistol Universal Oil goes a long way. It's in our Universal Oil range and the home and household collection. Questions about a particular window? Call +44 (0) 7817 267314 or email sales@ballistol.co.uk.
More guides: How to Unfreeze a Frozen Lock · How to Lubricate a Garage Door · How to Stop Rust on Metal
Written by Ballistol UK. How we write and check our guides.
This guide is general advice. If you're unsure whether a product suits your item, contact Ballistol UK or a qualified professional first, and don't use it until your concerns have been answered.
