Water droplets on window glass are one of the most common household worries. The good news is that most condensation is harmless and fixable. The important thing is working out which type you have, because the cause (and the cure) is different for each.
Condensation on the inside of the glass
This happens when warm, moist indoor air meets a cooler surface. Cooking, showering, drying washing indoors and even breathing all add moisture to the air, and the glass is usually the coldest surface in the room.
It is most common on cold mornings and in bathrooms, kitchens and bedrooms. It does not mean your windows are faulty, but if it is left it can lead to mould around the frames and on walls.
- Use extractor fans or open a window when cooking and bathing.
- Keep trickle vents open so fresh air can circulate.
- Dry washing outdoors or in a ventilated room where you can.
- Keep a steady background heat rather than short bursts of high heat.
- Wipe away moisture in the morning and consider a dehumidifier in problem rooms.
Condensation on the outside of the glass
Surprisingly, this is a sign your windows are doing their job. Highly insulating glass keeps heat inside, so the outer pane stays cold enough for dew to form on clear, still nights, just as it does on a car windscreen.
It clears by itself once the sun comes up or the air warms. There is nothing to fix.
Condensation or mist between the panes
If you can see fog or droplets trapped between the panes that you cannot wipe away, the sealed unit has failed. The seal around the edge has let moist air in, and the unit will not recover.
The glass unit (not the whole window) can normally be replaced, which is far cheaper than replacing the full frame. Our repairs and servicing team can measure up and swap the unit.