Why do I have mist in my double glazing? How to fix blown windows


Do you have mist in your double glazed windows?

This is actually known as condensation and this issue with double glazed windows is quite common, especially in old windows or new windows that have been installed incorrectly.

The good news is that you can do something about blown double glazing.

Mist in Double Glazing Causes

Mist in double glazed windows can be incredibly frustrating, not only does it impact your vision through the windows, but it can look incredibly unsightly and is a sure sign that there’s something wrong.

The mist is in fact the build up of condensation between the two panes of glass that make up the double glazing.

In reality, the gap between the two panes of glass should be water tight and only contain an insulating gas (typically argon).

Mist or condensation in the middle of the two panes means that the seal is broken and water has made it’s way into the space. Essentially, the double-glazing seal in the windows is broken and is allowing moisture in.

Why is mist in the double glazing problematic?

The moisture getting it’s way into the space between the two glass panes is an issue for a few major reasons:

  • It looks unsightly.
  • It impacts your view through the window.
  • It impacts the insulation properties of the window itself, a key function of their efficiency.
  • It impacts their ability to insulate outdoor noises.

Impact of misted double glazing

As highlighted in the list above, moisture between the window panes is not just unsightly, it also has practical implications.

Misted double glazing is caused by an issue with the seals in your windows. This means that if moisture can get in, so can cold air, along with warm air escaping.

This damages the energy efficiency of your home and can even affect your health and wellbeing. It can cause a problem with condensation and mould as well. It can also mean a big money pit, as you will need to invest in more energy efficient windows and maybe even insulate the outside to stop the cold from getting in.

Check out our complete guide on the price of new windows, if you want a rough idea of how much you can expect to pay (including installation). You can also read about the various window styles available, as well as double glazingtriple glazing and decorative windows.

Where is the condensation?

If you see mist or condensation on your windows, the first thing to do is to determine where it is.

Is it on the outside of the window? Or is the moisture actually trapped inside of the double glazing panes? I.e. the space between them.

If the condensation is on the outside of the window, this is usually nothing to worry about and is simply due to outdoor weather conditions and temperatures.

However, if the moisture is actually trapped between the two panes of glass, this is a sure sign that the window seal is broken and in need of repair.

How to repair misted double glazing yourself

The good news is that in some cases, you may be able to repair the mist in your double glazed windows without the need to seek professional services.

There are misting repair kits, which you can easily pick up from local hardware stores and online, however, if the misting is severe, then these are unlikely to fix the issue.

The other problem with these misting repair kits is that the DIY instructions are not for the light hearted and can involve having to drill holes directly into the glass.

You can attempt to replace the window seal yourself, which is relatively the straightforward. The problem is that this measure won’t remove the moisture already trapped between the two panes of glass.

Therefore, the only real solution is to have the glass panes replaced. This does not mean the window casing and frames have to be replaced, so will not be as expensive as a completely new window installation.

Warranties for blown double glazed windows

Before getting a brand new quote for having your windowpanes replaced, it’s a wise idea to check your windows existing warranty and the terms and conditions.

Some window warranties do cover the repair of window misting for a certain period of time e.g. 2, 5 or 10 years. If you don’t see any information in the warranty that covers the topic, then it’s always worth giving your window installation company a call directly and explaining the situation in full.

Even if your warranty has expired or it does not include the repair of a broken window seal, they may still be willing to carry out the repair at a fraction of the cost that another company may have quoted.

How to avoid window misting problems in future

If your windows are very old, it’s likely that the misting is a sign of wear and tear and that it’s time to replace your windows.

However, if your misted windows are relatively new, it’s likely that they were installed poorly. Therefore, the best way to avoid your double glazing misting up in future is to avoid a poor installation.

Do not just allow anybody to install new windows, instead do your due diligence and check their previous history.

Thanks to the digital world, it’s easier than ever to check a window installer or window companies reputation. For example, you can check their previous customers reviews on platforms like Trust pilot.

Ultimately, just like anything, windows get old and worn and one day will need to be replaced. Therefore, if your windows look visibly old, the seal has likely reached the end of it’s run and a new window installation is inevitable.

The good news is that today there are lots of affordable window deals and even those that enable you to spread the costs of new windows using finance.

Get a Free Quote for your New Windows Today

The number one advice when shopping for new windows for your home is to secure at least three quotes from local installers.

Your priority shouldn’t necessarily always be price, since the reputation of the company, aftercare and the warranty are also all important factors.

Going for the cheapest may mean paying less upfront, but in the long term you may pay more in terms of time, stress and repairs.

Here at Window Central, we have a network of reliable and trustworthy window installers throughout the UK. Request your free quote now and you should receive a range of quotes from our network in the next 24 hours (at the latest).

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