uPVC is chosen largely because it does not need looking after. No repainting, no polishing, no anti-rust treatment, no termite worry. That is true, and it is the main reason the material took over.
What it does not mean is that a window can be ignored entirely for twenty years. The frame looks after itself. The moving parts — tracks, gaskets, hinges, rollers, drainage — benefit from about twenty minutes of attention twice a year.
Do that and a uPVC window will outlast most of what surrounds it. Skip it and the failures that appear are almost always in those same few places.
The twice-yearly routine
Two sessions a year works well in Bengaluru's climate: one before the monsoon and one after it. What follows takes under half an hour for a typical flat.
Clean the tracks
This is the single most valuable thing on the list, and it applies to every sliding window and door.
Dust, grit and organic debris accumulate in the bottom track. Left there, it does three things: makes the sash progressively harder to move, grinds the rollers as they run over it, and blocks the drainage slots so water sits in the track instead of exiting.
Vacuum the track first with a narrow nozzle, then wipe with a damp cloth. A soft brush helps with the corners, where debris compacts hardest. Do not use oil in the track — it collects dust and makes the problem worse.
Check and clear the drainage slots
Every uPVC frame has small drainage openings routed through the bottom of the outer frame. Their job is to carry away rain driven past the outer seal.
They are easy to miss and easy to block. A blocked drainage slot is one of the most common causes of a perfectly good window leaking during heavy monsoon rain.
Locate them on the external face of the bottom frame, and clear each with a thin implement — a cocktail stick works, a screwdriver does not. Then pour a little water into the track and check it runs out.
This is the check to do before the monsoon, not after.
Inspect the gaskets
The rubber seals around the sash are what create the airtight, watertight closure. Good quality EPDM gasket stays flexible for many years; it does eventually harden, shrink slightly at the corners, or get displaced from its groove.
Run a finger along the gasket and look for gaps, flattened sections, or places where it has pulled out of the channel. A displaced gasket can usually be pressed back in. A hardened or shrunken one needs replacing, which is a straightforward job for a service technician and much cheaper than the consequences of leaving it.
A useful test: close the window on a strip of paper and pull. If it slides out easily at one point and grips at another, gasket compression is uneven.
Lubricate the hardware
Hinges, locking mechanisms, handles and rollers all benefit from occasional lubrication. Use a light machine oil or a silicone spray — not a general-purpose penetrating spray, which attracts dust.
Apply sparingly to moving parts only, and wipe away any excess. Oil on a gasket degrades it.
If a handle has become stiff, that is usually the lock mechanism rather than the handle itself, and it is worth addressing before it seizes.
Check the fixings and seals around the frame
Look at the joint where the frame meets the wall, inside and out. The external sealant bead should be continuous and intact. Sealant does degrade under sustained UV exposure, and a gap there lets water into the reveal.
Small cracks can be resealed. Extensive failure means the bead needs cutting out and redoing — not urgent, but not something to leave for years.
Clean the frames and glass
Warm water with a little mild detergent, and a soft cloth. That is genuinely all uPVC needs.
What to avoid: abrasive cream cleaners, scouring pads, solvent-based cleaners and bleach. All of these can dull or micro-scratch the surface, and once the finish is dulled it holds dirt more readily — so an aggressive clean makes future cleaning harder.
For stubborn marks, a dedicated uPVC cleaner is the right product. Do not reach for a household solvent.
Before the monsoon
Bengaluru's monsoon is the period that tests a window hardest, and the checks that matter are specific:
- Drainage slots clear — the highest priority item, as above.
- Gaskets seated and flexible, particularly along the bottom of the sash.
- External sealant intact around the full perimeter of the frame.
- Tracks clean, so water can reach the drainage rather than sitting behind debris.
- Sashes closing evenly — an uneven gap means one part of the perimeter is not sealing.
Before summer
Heat works on a window differently. uPVC expands and contracts with temperature, and sustained heat is what eventually stiffens gaskets.
- Check gasket flexibility. Hardening shows up after hot seasons more than wet ones.
- Lubricate hardware. Thermal movement means moving parts work slightly harder.
- Check operation of every sash. A sash that has begun to bind will bind worse as temperatures rise.
- Look at dark-finish frames particularly. Laminated profiles in darker colours run hotter, and any movement shows up there first.
What not to do
A short list, because each of these causes damage that is difficult to reverse:
- Do not pressure-wash uPVC frames. High-pressure water forces past gaskets and into drainage channels from the wrong direction.
- Do not use abrasives or solvents. The surface finish is doing real work; once it is dulled, it stays dull.
- Do not oil the tracks. Clean and dry is correct. Oil turns dust into grinding paste.
- Do not paint the frames. It converts a maintenance-free window into one needing periodic recoating, and usually ends warranty cover.
- Do not force a sticking sash. Something has changed — packing, hinge adjustment, debris. Forcing it damages hardware and can distort the sash.
When to call a technician
Most of the above is homeowner work. These are not:
- Condensation between the panes of a double-glazed unit. The unit seal has failed and the glass needs replacing. It cannot be dried out.
- A sash that has dropped or no longer closes square. Usually a hinge or roller adjustment, and there is genuine adjustment built in — but it needs doing correctly.
- A lock that will not engage smoothly. Multi-point mechanisms can be adjusted; forcing them breaks them.
- Persistent water ingress after the drainage has been cleared and the sealant checked.
- Visible bowing of a frame or sash. Points to a reinforcement or installation issue rather than a maintenance one.
A window that has been fitted correctly and given twenty minutes twice a year should need very little beyond this. When something does go wrong, catching it early is almost always the difference between an adjustment and a replacement.
Frequently asked questions
How often should uPVC windows be cleaned and maintained?
Twice a year is sufficient in most Indian climates — once before the monsoon and once before summer. Each session takes under half an hour for a typical flat and covers track cleaning, drainage slots, gasket inspection, hardware lubrication and a general clean.
What should not be used to clean uPVC window frames?
Avoid abrasive cream cleaners, scouring pads, solvent-based cleaners and bleach. All of these can dull or micro-scratch the surface finish, and a dulled surface holds dirt more readily, which makes future cleaning harder. Warm water with a mild detergent and a soft cloth is what uPVC needs.
Why is my new uPVC window leaking in the monsoon?
The most common cause is blocked drainage slots in the bottom of the outer frame. These carry away rain driven past the outer seal, and they block easily with dust and debris. Clear them with a thin implement before the monsoon and pour a little water into the track to confirm it runs out.
Can condensation between double-glazed panes be fixed?
No. Condensation inside a sealed double-glazed unit means the perimeter seal of the unit has failed, and it cannot be dried out. The glazed unit needs replacing, though the frame and hardware are usually unaffected.
Should uPVC window tracks be oiled?
No. Tracks should be kept clean and dry. Oil in a sliding track collects dust and grit, forming an abrasive paste that wears the rollers faster than debris alone would. Lubricate hinges, locks and rollers sparingly with light machine oil or silicone spray, but keep the track itself dry.
Want a quote for your own openings?
Our team covers Bengaluru and surrounding areas.
