Misted Double Glazing: Clear It, Fix it, The Cost & Benefits

If you’ve ever noticed your view of the outside world is obstructed by water drops and streaks, you may have a condensation problem within your property or you may have a failed glass panel within the window.  When the glass panel fails in a double glazed window it can allow moisture between the two panes inside the cavity. When either happens, you might find that you lose your view of the outside world and your windows might look unattractive. 

If this has happened to you, don’t panic. It doesn’t necessarily mean that you’ll have to replace your windows. And if your windows are still under warranty, you might be entitled to a free glass replacement as this could be a sign that the window seals have failed prematurely. 

If you’re dealing with misted double glazed glass units or condensated windows, this article should hopefully provide some answers for your situation. We will explore why this happens, what steps you can take to prevent it, and your options for repairing misted windows. There is a simple way to fix this that doesn’t cost the earth. Read on to learn more about the all-too-common problem of misted double glazing or condensation inside your property.

What is Condensation?

What is Condensation?

Condensation is a process by which water vapour in the air turns into liquid water. It occurs when the temperature of an object falls below the dew point of the surrounding air, and it can happen on any surface that can cool below that temperature.

Condensation is most common on surfaces that are cool to the touch, such as windows or refrigerators. When these materials are exposed to warm, humid air, they absorb some of the moisture content and release it again when they cool down.

When this moisture gets trapped between window panes, it cannot easily be removed. The seals designed to keep moisture out will also trap a lot of it in place.

The location of the condensation will determine if it is a cause for concern.

Condensation on the inside pane of the room: This could mean that you have a problem with air circulation in your home. It’s also common in rooms that are colder than other parts of your home. When moisture builds up on the inside of your windows, this means that there is moisture trapped in your home. 

This will be attracted to the coldest surfaces, and this often includes windows. If you have condensation inside your home, try opening a window to allow moisture out. You should also avoid drying clothes in your home, as this can lead to moisture build-up.

Condensation on the outside: Condensation on the outside of your windows means that your windows are working efficiently. This is common in the early morning as moisture from the air settles on colder surfaces. This should evaporate once the sun rises. No action is needed when you have condensation on the outside of your windows. This is more common on colder windows such as conservatory windows or porch windows. Further guidance on external condensation can be found – https://www.ggf.org.uk/wp-content/uploads/2018/01/50.1-Condensation-Some-causes-some-advice.pdf If this bothers you, you could use a special window film to help prevent your windows from getting so cold. This should help to reduce the presence of condensation in the mornings.

Condensation between your window panes: If the condensation cannot be wiped away on the inside or outside, this means that it has settled between the panes. When this happens, it means that the seal around the double (or triple) glazed glass unit has broken down & failed and needs to be replaced.

Can I clear misted double glazing myself?

Can I clear misted double glazing myself?

You might be able to find instructions online that show you how to repair misted double glazing using DIY methods, however, we wouldn’t recommend this option. This can be particularly dangerous if you are trying to treat windows above ground level. You will need to be able to access the outside windows safely, and this is difficult without the right equipment.

We also don’t recommend the DIY route as it could cause permanent damage to your windows. If you make a mistake while clearing misted double glazing you might need to repair the entire glass unit or window frame, which would be much more expensive.

Removing the seals or gaskets on your windows yourself means that the glass panes may be free to move around. This is a considerable hazard and we don’t recommend this route. Unless you are an experienced glazer, this task is best left to the professionals. 

If anything goes wrong your warranty on the windows would no longer be valid. Resealing a misted glass unit or replacing the gaskets to a window frame does not come with a warranty, however a guarantee will be given by a professional glazing company when replacing a failed glass unit.

Why does this happen?

Why does this happen?

Internal condensation within the room or property will form droplets of moisture against the cold surface of the glass on the window panes within the room.  There are various causes – including lack of ventilation, high moisture environments such as in bathrooms and kitchens, and drying washing inside your home.  Further information on the causes can be found at https://www.ggf.org.uk/publications/consumer-leaflets/condensation/ 

To understand why misted failed double glazing happens, we have to think about the structure of the window. There are two panes of glass with a void in the middle. The void helps to trap a layer of air which helps to prevent heat loss in winter and very high temperatures in summer.

When manufacturers make new windows, they include a small amount of desiccant in between the seals. This is designed to absorb any moisture that makes its way between the panes. Over time, this will lose its effectiveness, which means that any moisture in between the panes will start to become visible.

Almost all windows are prone to condensation. New windows are just as likely to have problems with misting as older window units. Whether the frames are made from aluminium, timber or uPVC, there is the risk of the seals breaking down over time and allowing moisture to build up between the panes.

A rubber gasket seal is designed to keep out external moisture, but this can wear down over time. Rubber is prone to break down after exposure to heat, cold and moisture. Once moisture is inside the void, it gets heated and cooled throughout the day. It can break down the sealed glass unit causing a misted or streaked appearance within the glass unit.

Sometimes window misting is the result of a manufacturing fault, but more often it is simply a case of the seals and protective measures breaking down over time. While it might be an unsightly problem and a sign that your windows aren’t working efficiently, it isn’t an urgent repair.

How can I prevent it?

How can I prevent it?

Window condensation is a common problem, especially in the colder months. In the UK, condensation is far more common due to the high humidity and colder temperature in winter. At the first signs of condensation in your windows, you need to work out what type of condensation it is.  You can seek advice from a reputable glazing company or speak to your window supplier. This will help to limit the damage and choose the right course of action so ensure that you do not have to live with misty windows. 

Internal condensation within the room can be prevented by opening your windows for a short period of time every day, or opening your window trickle vents if you have them, or making sure the room is adequately ventilated. 

Misty windows not only limit your view of the outside but can possibly indicate that something is amiss with your double glazing. This will mean that your home is not as efficiently insulated as it could be. While it might not be possible to eliminate the risk of misty double glazing, early intervention may help to prevent it from becoming an eyesore. 

The prevention of a failed glass unit in a timber window frame is different to the prevention of it in UPVC and aluminium frames.  Timber windows need to be regularly maintained, including staining and painting, in order to prevent water ingress. All double glazed windows should have desiccant inside to help control moisture, so you might not notice right away when your window seals have failed.  Further prevention information can be found at – https://www.ggf.org.uk/wp-content/uploads/2018/01/50.1-Condensation-Some-causes-some-advice.pdf

How to fix double glazing condensation

How to fix double glazing condensation

Internal condensation in a room is a common problem with some types of double glazing. Condensation can be prevented by using a venting system, which will help to remove moist air from the room. A venting system includes a vent in the frame of the window and a cowl on the roof or wall.

In this article, we will be discussing how to fix double glazing condensation with a few simple steps. We recommend hiring a professional to fix double glazing condensation as there is a reduced risk of damaging your windows or property. When windows are located in hard-to-reach areas, you run the risk of personal injury and damage to your property.

To repair the issue, one method uses a desiccant to absorb the moisture. A small hole is drilled to access the glass pane unit. A special drying agent is then injected or pumped into the hole to help dry out the window. An anti-fogging agent can also be added to help avoid the problem in the future. However this can be risky and often does not come with any guarantee.

If the window gasket seals have perished or shrunk these can sometimes be replaced. This will help prevent water and moisture getting to the sealed glass unit. This is an good choice for bringing a new lease of life to windows rather than paying to replace the entire window. The right gasket sizes are essential to completing this repair. If the seals are not added correctly, then there is the risk that the issue will return.  This will not resolve the issue of a failed misted double glazed glass unit.

When should I consider replacing a window?

When should I consider replacing a window?

If your windows are quite new, you may be covered under the manufacturer’s warranty. In this instance, you might want to replace the entire glass sealed unit. If there is moisture present within the window panes, this means that the glass unit within the window has failed. 

In this instance, you will be far better off contacting the manufacturer and finding out about having the panes replaced. In some cases, they might even replace the entire glass sealed unit under guarantee.  You should then check if your warranty continues from the date you purchased the windows, or starts anew from the date the glass was replaced. 

Some windows may be more prone to issues with misting, so it would be more efficient to simply replace the unit rather than continue to pay for repairs. Some manufacturers will guarantee their windows for up to 15 years, so it is certainly worth checking if you are covered. 

If your windows are quite old and not as efficient as they could be, it might be worth considering an upgrade. If you’re thinking about selling your property in the future, new windows with a good energy efficiency rating could help to increase the asking price for the property. New windows can also improve the appearance of your property. 

How much does it cost to fix double glazing condensation?

How much does it cost to fix double glazing condensation?

The cost of a double glazing condensation fix depends on several factors. For example, the type of condensation, the type of window frame, and the size and location of the window. Make sure you shop around for a few quotes before choosing a company to fix your misted double glazing, as prices can vary between suppliers.

We have compiled a list of some factors that can affect pricing:

Type: There are three types of condensation – internal, external and between the panes. Internal condensation occurs when there is a problem with moisture and ventilation within the room or property. External condensation means that your windows are working efficiently. No action is needed when you have condensation on the outside of your windows. Between the panes, a failed double glazed glass unit that will need replacing.

Window frame: The type of window frame can also affect pricing as different materials require different fixes to solve condensation issues. 

Location: The location also plays into how much it costs to fix double glazing. Condensation in a difficult to reach skylight could be more expensive to fix than condensation in a ground floor window. Windows over conservatories are also more difficult to reach.

Size: The size of the window will also determine how much it costs to repair and replace the broken seals. A very large window will take much longer to clear and will therefore be more expensive.

The benefits of replacing window seals

The benefits of replacing window seals

Window gasket seals may seem like a small, insignificant thing. But they can make a huge difference in your home’s energy efficiency. Replacing old seals with new ones can save you money on your utility bills and help the environment by reducing greenhouse gas emissions.

Window gaskets are usually made of foam or rubber and sit between the window frame and the window sash. They provide an airtight seal between the glass and the frame to keep heat inside during winter and cool air inside during summer.

There are some benefits to replacing window gaskets, these include:

Window seals

1)  Reduce heat transfer through windows. This can help to keep your home warmer in winter and cooler in summer.

New window seals

2) New window gaskets will give you higher energy efficiency ratings on your home’s insulation, which means lower utility bills for you.

Getting rid of window

3) Can also help to boost the value of your property. Trying to sell your home with perished gaskets is likely to damage the asking price. Buyers might think the property is more run down if you have perished gaskets around your window frames.

You’ll improve the view

The benefits of replacing failed double glazed glass units

1) Getting rid of misted condensation panes will help boost the value of your property.  Trying to sell your home with misted failed units is likely to damage the asking price.

2) Energy efficiency. This means a lower carbon footprint for your property. With energy bills on the rise, everyone is looking for simple steps they can take to improve the efficiency of their homes.

Window condensation

3) You’ll improve the view from your home if you address problems with window condensation. You might not realise how much this affects your mood, but having a clear view of the outside can be a real mood booster, particularly on brighter days.

4) Window condensation makes your property look tired and run down. If you want to avoid your home looking like an eyesore to you and your neighbours, it’s a good idea to act quickly. Clearing out condensation is not an expensive job, but it can make a significant difference to your home’s appearance.


While misted windows might be an eyesore, they are not the end of the world. Once you know what to look out for, you will know when it is time to act. Double glazing misting is a common problem, but it isn’t one that you have to live with.

The first step to dealing with this problem is to learn how to identify it. If the condensation isn’t formed on the inside or outside of the window, then you know that you have a moisture problem between the panes.

When this happens, you have two options:

  1. Repair the issue by removing the moisture and fixing the seals. Not the recommended option as this can be risky and the longevity of the repair is doubtful.
  2. Replace the entire glass windowpane.

The first option can be a cost-effective choice if your windows are no longer under warranty. 

If you still have a warranty, it could be worthwhile to replace the panes free of charge, as this is a sign that the windows have failed prematurely.

The complete replacement of the glass pane is the recommended route and would come with a new warranty.  Employee the services of a reputable glazing company and you will also receive a brand new guarantee.

Double glazing

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