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Should Double Glazing Ever Get Condensation?

Whether they were there when you moved in, or you’ve had new double glazing units installed yourself, it’s important to know what’s normal and what isn’t when it comes to condensation. You may assume that if your windows aren’t clear all the time, then there’s something wrong with them. This can sometimes be the case, but only when talking about condensation between the two panes.

To ensure you don’t continue with failed double glazing units (DGUs) or worry unnecessarily about a ‘problem’ which is completely harmless, check out our guide below. You may not need replacement double glazing units after all!


My Double Glazed Windows Have Condensation on the Outside

In the colder months, you may notice that your DGUs have some dew or condensation on the outside of the window pane. This can be frustrating, especially if you want to see out, which, after all, is the point. This is a rather new problem when it comes to double or triple glazed window units, as it’s to do with how efficient they are.

The government, in recent years, has set out guidelines on how efficient newly installed windows have to be. This is all for the greater good; the more efficient your windows, the warmer your home will be. This will lower your bills and help the environment as it uses less energy. While this is all brilliant, it does mean that much less heat is lost through your windows and therefore they’re cooler on the outside.

It’s this cooler temperature that creates the condensation. As the surface of the glass is cold, the air around it reacts with this temperature and condenses, creating moisture on the outside. As the air warms up, the condensation will naturally clear. This is an annoying problem, but one which is there for the right reasons. If you have condensation on the outside of your double or triple glazed windows, then it’s likely to be because they’re doing the job they’re meant to do.

This doesn’t mean that, if you don’t have condensation on the outside, your windows are not working properly. There are many different factors at play – so the fact your home faces a certain direction or is shaded by a big tree can make a difference. Rest assured that this type of condensation is nothing to worry about. If it’s particularly bad, there are some sprays on the market that you can use to ‘waterproof’ your windows. Your local hardware store should have more information.


My Double Glazed Windows Have Condensation on the Inside

Having condensation on the inside of your windows can be a really annoying problem. Not only can it pool on the window sills inside your home, but it can also mean mould is more likely to grow on your walls and in other areas. Once mould and damp have taken hold in your home, it’s very hard to get rid of and can, in extreme cases, cause health problems.

So is it the fault of the windows? Some homes tend to get condensation on the inside when new DGUs are fitted, and this is assumed to be the fault of the window. However, this is another problem which may have been exacerbated by the fact that the window is simply very efficient.

GlazingLots of water vapour is produced inside your home every day and there’s not a lot you can do to prevent that. Breathing, drying clothes, cooking, showering – these activities all release water molecules into the air. When this warm, damp air hits a cold surface (such as a window), it turns into liquid water, which forms the condensation. The only way you can stop this from happening is ventilation.

This issue is a bit of a catch-22 situation. In order to ventilate your home, you need to allow air to move in and out. This defeats the object of efficient DGUs which are there to keep the heat in, but it’s the sheer efficiency of the windows which may be causing the moisture build-up in the first place. Older or poorly-fitted windows will let air in and out all the time, which means they may not suffer with condensation so badly. However, they will also make your home colder and more expensive to heat.

The best solution is to open your windows when you cook and when you take a bath or shower, dry your window sills if you see moisture on them and open your windows to ventilate your home for a little while each day. Try to contain steam to one room only and leave a window open until this has cleared – this should stop moisture from travelling to other areas of your home. There’s unlikely to be anything wrong with your windows if this is happening, so don’t order those replacement DGUs just yet!


My Double Glazed Windows Have Condensation Between the Panes


If the condensation on your windows is not on the inside or the outside, but between the two (or three) panes where you can’t get to it, then you may have a problem. The fact that moisture is building up inside the window means that the seals have stopped doing their job properly.

Double Glazed UnitsThe seals keep fluctuating temperatures from affecting the window by creating a completely airtight environment between the panes. When the seals degrade or are damaged through age or wear & tear, the constant environment between the glass is compromised. This means that fluctuations in temperature (as night turns into day, for example) can cause moisture to collect in the space.

The only way to have this rectified is to have your double glazing units replaced. In most cases your window frames (if good quality) can stay where they are – it’s just the glass that will need replacing. Many double (or triple) glazing fitters will put a long guarantee on DGUs (Evander have a 5 year guarantee on double glazed units), so check to see if they’re still under warranty before ordering replacements.


When condensation builds up between your window panes, it means that your home is no longer as efficient as it was, and you may notice your bills rising, particularly in the winter. The sooner you can order replacement double glazing units the better. If you’re worried about your windows and want to speak to us, then feel free to give us a call on 0345 145 0130 or email Enquiries@vps247.co.uk.