PVC window maintenance: the annual calendar to make them last 50 years

PVC is the “easiest” of window materials: no painting, no timber treatments, no oxidation the way aluminium can have. But “easy” doesn’t mean “zero maintenance”. The windows that genuinely last 40-50 years are the ones someone has spent 30 minutes a year on. The ones that after 15 years start closing badly, dripping, sealing poorly, are almost always the ones nobody ever touched. This is the calendar we give customers after installation, simplified to be realistic.

What you need as a basic “kit”

Full-year maintenance requires very little, total cost €30-40:

• Neutral detergent (liquid Marseille soap or diluted washing-up liquid). No solvents, no ammonia, no acetone, no methylated spirits.
• Microfibre cloths (two or three)
• Hardware oil specific to the fittings — the one supplied by the hardware manufacturer (Maco, Roto, Siegenia) or an equivalent technical oil such as Ballistol or WD-40 White Lithium. Not cooking oil, not standard WD-40 (it degreases, dries out, and after a few months is worse than doing nothing).
• Neutral white petroleum jelly or silicone stick for the gaskets.
• Soft-bristle brush for deep dirt in the grooves.
• Vacuum cleaner with a narrow nozzle for drains and drainage channels.

That’s it. No miracle products, no “PVC revivers” from teleshopping: PVC doesn’t need reviving, it needs cleaning.

Cleaning the profiles: three times a year

PVC gets dirty in a predictable way: pollution, pollen, road dust, and damp from rain that leaves streaks. Dark surfaces (anthracite, brown) show it more, white ones less but they get just as dirty.

Frequency: three passes a year are enough for 95% of cases. In heavily polluted urban areas (near motorways, heavy traffic) even four. In the mountains or countryside, two can be sufficient.

How to do it:

1. Warm water with a little neutral detergent, soft microfibre cloth.
2. Clean from the top downwards, on both the outer and inner frames.
3. Pay particular attention to the corners and gasket grooves — that’s where dust and debris build up.
4. Rinse with a clean damp cloth and dry immediately.

On white profiles that yellow: modern lead-free PVC does not structurally yellow. If you see yellowing on your frame, it’s usually organic dirt (pollution, cigarette smoke) or sun acting on pollution deposits. It comes off with a thorough neutral-detergent clean; if it really won’t shift, there’s a specific product (Cosmofen 5 or equivalent) but it must be used with care and only on the frame, never on the gaskets.

Hardware: lubrication and adjustment once a year

The hardware is the part that does mechanical work and is therefore the part that wears. Maco, Roto and Siegenia are the three most-used manufacturers in serious windows and all recommend annual lubrication.

Frequency: once a year, in spring or autumn, when the weather is dry.

How to do it:

1. Open the sash in the tilt position.
2. Identify the locking points along the frame (the small latches/bolts that engage the strike plates). There are usually 4-6 per sash on the long sides and 1-2 on the short sides.
3. Vacuum dust and debris from all the locking points and from the frame’s side grooves.
4. Apply 1-2 drops of hardware oil to each bolt and each strike plate. One drop, not a spray. Too much oil attracts dust and does more harm than good.
5. Put a drop on the hinges too (top and bottom pivots).
6. Open and close the sash 5-10 times to spread the oil.
7. Wipe away any excess with a dry cloth.

Adjustment: every 3-5 years the hinges may need re-adjusting. Signs to watch for:

• The sash rubbing against the frame
• The sash closing stiffly
• The sash not closing fully at handle height
• New draughts that weren’t there before

Adjustment is done with an Allen key on the hinges (usually 4 mm). If you’re not confident doing this yourself, it’s one of the rare cases where it’s worth calling the installer: €60-80 for a call-out to adjust all the windows in a flat. An experienced installer does it in half an hour.

Gaskets: the real determinant of the window’s lifespan

EPDM (synthetic rubber) gaskets are what provide the seal. There are usually two per sash: an outer contact gasket and a central one. They last if looked after, and dry out and crack if ignored.

Frequency: twice a year, spring and autumn.

How to do it:

1. Clean: a damp cloth with water and a little neutral detergent, wiping the full length of the gaskets to remove dust and debris.
2. Dry with a clean cloth.
3. Apply a thin film of white petroleum jelly or silicone stick to the gasket, spreading it with your finger.
4. Do not use oil (it makes the rubber lose its elasticity over time), nor mineral greases.

Gaskets last 15-25 years if properly looked after, 8-12 years if never touched. (To understand how the PVC profiles they sit in are built, read the complete guide to PVC windows.) Once they’re past their life, they’ll look cracked, deformed, “tired”. At that point they’re replaced — a job the installer does in 1-2 hours per flat, average total cost €150-300.

Drains and drainage: the thing nobody sees

Beneath the bottom contact strip of every PVC window sash there are small drainage holes. Their job is to let out condensation or rainwater that gets into the frame. If they block up (dust, leaves, dead insects), water pools inside the profile and can, over the long term, cause sealing problems.

Frequency: once a year, ideally in autumn before the heavy rains.

How to do it:

1. Open the sash. Look at the bottom of the fixed frame.
2. Find the small holes (1-2 per linear metre, usually 5-8 mm in diameter), often covered by a small angled cap.
3. Vacuum dust and debris out of the holes with the narrow vacuum nozzle.
4. Check they’re clear by blowing through them or passing a soft wire through (no rigid metal, it would cut into the PVC).

In ten years of service work I’ve opened up windows for repairs where the drains had 2 cm of soil/dust/insects inside. It’s one of the most common causes of mysterious dripping.

Things you must never do

• Aggressive solvents: acetone, nitro thinner, methylated spirits, ammonia. They attack the PVC surface and leave it permanently dull.
• Abrasive scourers (the green side) or steel wool: they scratch the surface irreversibly.
• High-pressure washers on windows: water gets into the hardware mechanisms, washes away the lubricant, saturates the seals. It destroys in 2-3 washes what should last 20 years.
• Excess oil on the hardware: attracts dust and turns into an abrasive paste.
• Painting the PVC: never paint it. Adhesive films exist that can be applied after professional intervention, but they’re an emergency fix. A DIY spray paint job lasts 1-2 seasons before it starts flaking.
• Standard WD-40 on the hardware: degreases, dries out, makes the parts noisy and prone to wear. Use a specific technical oil.
• DIY silicone sealant to “close up a draught”: if there’s a draught, it needs adjustment, not silicone. Silicone blocks the sash’s movement and comes away within 1-2 years.

Warning signs — when to call for assistance

• Sash closes stiffly: probably hinge adjustment or worn hardware. Call-out cost €60-120.
• New draughts that weren’t there before: adjustment needed, or a gasket needs replacing. €80-200.
• Persistent condensation on the inside of the glass: usually excess ambient humidity (ventilate more), but if it’s on the outer frames it could be a sealing problem. Free quote.
• Dripping from below: likely blocked drains or deteriorated external sealant. €100-300 depending on the work.
• Fogging inside the cavity (not on the glass surface itself): the unit has lost its seal and the glazing needs replacing. €80-150 per pane. Not urgent, but should be done within 1-2 years.

Ten-year service

Every 10-12 years it’s worth having a full professional check carried out:

• Replacing all the gaskets even if they still look fine (they’re cheap, and account for half the job)
• Full hardware regreasing with disassembly
• Checking and restoring external sealant
• Full adjustment

Average cost for a flat with 6-10 windows: €600-1,200 total. Done on time, it extends the window’s life by a further 10-15 years without major work.

Summary table

Task	Frequency	Time per flat	Cost if professional
Profile cleaning	3 times/year	1-2 hours	DIY
Hardware lubrication	Once a year	30 min	DIY
Gasket petroleum jelly	Twice a year	30 min	DIY
Drain cleaning	Once a year	15 min	DIY
Hinge adjustment	Every 3-5 years	---	€60-120
Gasket replacement	Every 15-20 years	---	€150-300
Ten-year service	Every 10-12 years	---	€600-1,200

The total ranges from 30 minutes a year DIY to a ten-yearly service every decade. Over a window’s 40-50 year lifespan, that’s a few hundred euros against the alternative: early replacement at 20-25 years due to poor maintenance, costing €8,000-15,000 in total for a standard flat.

The windows we manufacture are on average 20 years old when they get their first proper service. The ones that “survive” with no maintenance end up in landfill at 15. The maths is simple.

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Request assistance or a periodic maintenance check: we service windows and doors in PVC, aluminium or mixed materials (provided they are PVC, aluminium or mixed).