Why a damaged frame matters more than it looks
Window frames are not just something to hold the glass. They are the seal between the building and the weather. Damage opens gaps, and gaps do three things: let conditioned air out so the air conditioning runs longer, let dust and noise in, and let monsoon water track into the wall — where it becomes damp plaster and, eventually, mould.
Addressing it early is the difference between a repair and a replacement.
What actually goes wrong here
Mumbai’s combination of heavy rain, salt air and strong sun is unusually hard on frames, and each material fails differently.
Timber swells in monsoon damp, then shrinks when it dries, which opens joints. Once water sits in an open joint, rot follows.
Mild steel rusts from the fixings and cut edges outward. Coastal humidity accelerates it, and paint over rust traps moisture rather than stopping it.
Aluminium does not rust but corrodes at the surface, and its thermal movement can work fixings loose over years.
uPVC is the most stable, but can discolour under UV and its hardware and gaskets still wear. Welded corners can also open if the frame was poorly reinforced for its span.
Across all four, the most common faults we are called to are broken seals, loose joints, faulty locks and blocked drainage slots.
Why DIY fixes rarely hold
Sealing a gap with adhesive or painting over a crack treats what you can see. It does not address why the gap appeared. Worse, sealant applied over the sill often blocks the drainage slots, so water that would have drained away now sits inside the frame.
Professional repair starts by finding the cause — a water path, a failed joint, movement in the opening — and fixing that. Otherwise the same fault returns in a season.
What a proper repair involves
- Timber: cut out the rotted section, splice in sound material, reinforce the joint, then treat and finish
- Metal: strip to bare material, apply anti-rust treatment, rebuild pitted sections where needed, recoat
- uPVC: replace failed gaskets and hardware, re-weld or reinforce where the corner has opened, clear drainage
- All frames: re-square and realign so sashes close onto their seals properly, and check the reveal seal
Alignment is the part most often skipped. A frame that is not square will not seal no matter how good the gasket is, and the window will feel stiff for the rest of its life.
What we check while we are there
A frame rarely fails on its own. We inspect hardware, glazing beads, seals and drainage at the same visit, because that is usually where the next problem is already starting — and catching it then costs almost nothing.
This is the same approach as our wider window service and repair work, which covers sealing, shutter repair, wooden window restoration and uPVC servicing.
When replacement is the honest answer
Sometimes it is. If the frame has moved substantially, if rot or corrosion is widespread rather than localised, or if you have repaired the same window twice already, replacement is cheaper over any reasonable horizon. We will say so.
Send us a photo of the frame and the sill, tell us what it is doing — sticking, leaking, draughty, rattling — and we will tell you which case it is.