In this article, Double Glazing Prices looks at what causes condensation and what to do if it appears on or inside your double-glazed windows.


How does condensation happen?

Condensation happens when water vapour turns to liquid.

When you see condensation on your window, it’s because the water vapour (which is hot) has been cooled and become liquid by the surface of your window pane (which is cold).

Steamed Window

Condensation on the outside of your double-glazed windows

Condensation on the outside of your windows indicates that your windows are doing exactly the job they’re meant to be doing, so there’s nothing to worry about.

The more warmth that your double glazing keeps inside your home means that your windows are going to have a hotter surface area. When the cold and moist air from outside hits the window, that’s when it turns into condensation.


Condensation on the inside of your double-glazed windows

If you see condensation on the inside of your double-glazed windows, this doesn’t mean that there’s something wrong with your window.

It does mean that there may be too much moisture in your home, though, and it’s a good idea to try to get as rid of as much of it as you can.

Condensation can shorten the lifespan of some types of window as the collected water may encourage the growth of mould. This mould may not only damage your windows – having both condensation in your home and the presence of mould can be bad for your health.

What can you do to reduce the amount of moisture in your home? Open your windows every day to let the warm air out and use extractor fans to remove damp air. If you can, dry your laundry outside.

Remember too that, in winter when it’s much colder, the chances of seeing condensation on the inside of your windows are much higher.


Condensation between the panes of your double-glazed windows

We’ve seen the condensation on the outside or the inside of your double-glazed windows is nothing to feel concerned about.

If you see condensation between the panes of your double-glazed window, there is a problem.

This means that there is an issue with the sealing of the window. Most likely, some part of the edge seal has failed and it’s allowing moisture in. You’re almost certain to need the sealant between the glass and the frame replaced. If it’s very bad, you may need to replace the whole window.

If you don’t do anything about the affected pane, the condensation can slide down the glass and onto your walls. Left untreated, black mould may start to develop or even worse, wet rot or dry rot.

Be sure to check the seals around your windows occasionally to make sure there have been no failures. Many homeowners do this by running their finger across the sealant, looking for any gaps or breakages.

As we mentioned earlier, as a matter of good ownership practice, try to keep the amount of moisture in your home to a minimum. If you don’t and a gap or a breakage begins to develop, the fog appearance inside your pane will become more pronounced and the chances of mould developing increase.