How to Diagnose and Fix Misted Double Glazing

How to Diagnose and Fix Misted Double Glazing

If you’re struggling to see through your windows because of a misty or hazy appearance, you could have an issue with condensation between the panes. Double glazing works by using two panes of glass held in place by the frame. 

There is a vacuum between the two panes of glass which helps to trap warm air. This gap is sometimes filled with inert gas like Argon to make them even more efficient. Argon is less conductive than air, so it helps to prevent heat loss.

To keep the inner section of the double glazing sealed, rubber gaskets are used to create an air-tight seal. When this seal is damaged or broken, air and moisture can get into the space between the panes.

This moisture turns to water vapour in the warmer space between the panes and then settles on the glass in the form of condensation. It can look misty or more like droplets of water throughout the day as a result of the air temperature.

If you have moisture between your double glazing, this will impact the efficacy of your windows and also make it difficult to see out. In this guide, we’ll explore how to diagnose this issue and what steps you will need to take to remedy it.

What causes misted double glazing?

What causes misted double glazing?

Misted double glazing is nearly always caused by faults in the sealants around your windows. It can also be caused by damage to your window frames which can allow water into the gap between the panes.

Damage to sealants can happen as a result of poor installation, damage due to bad weather, damage from UV exposure, damage from animals or birds, or simply due to wear and tear over time. The cause of the damage is not really relevant, unless you are concerned about this happening again.

Is it expensive to fix misted double glazing?

No, fixing misted double glazing is not expensive. The average cost for replacing a blown or misted double glazed window is around £250. The cost of the repair will depend on the size of the window. It’s possible to repair the misted double glazing, or you can choose to replace the unit to help avoid the issue from returning again.

If the misted double glazing is a long-term issue, there may be more extensive damage to the frame. Long term exposure to moisture can cause the frame to rust or rot, depending on the type of material it is made from. If this happens, the best option would be to replace the entire frame. This is common in homes that have been abandoned or neglected for a long time.

What is the best way to fix misted double glazing?

What is the best way to fix misted double glazing?

There are two ways to fix misted double glazing. You can either remove the moisture and restore the seal, or you can replace the window unit. Here is how to complete each type of restoration:

Repairing the misting

If you choose to repair the misting, you will need a professional to help remove the moisture from the frame and then install new sealants. To do this, they will have to drill a small hole in the frame and use this to insert a desiccant into the hole. 

This is designed to absorb large volumes of moisture and it will attract all of the moisture between the two panes. Next, the hole is sealed and the rubber gaskets around the window will be replaced. This will help to restore the seal and prevent the moisture from returning.

Once the seal between the window panes has been broken, there will no longer be a vacuum and any gas such as Argon will also escape. This will make your windows less efficient over time and isn’t always the most popular option.

Replacing the pane

Replacing the pane

For a more efficient fix, you will need to replace the pane while keeping the existing frame. You will also need a professional to complete this type of restoration.

First, they will choose the right sized replacement pane for the frame. They will then remove all sealants and remove the blown pane from the frame. They will then replace this with the new pane and install new sealants to hold it in place and prevent water from getting into the frame again. 

This is a highly effective method for getting rid of the misted look in a window and helping to prevent it from returning. The window should be like new, but it will keep the existing frame.

Can misted double glazing return?

Can misted double glazing return?

Yes, misting can return once it has been repaired. If you choose to replace the pane it is likely that you will have more time before the misting returns again. If it returns sooner, this could indicate an issue with your frames that needs to be addressed. 

This could include problems like dry rot in wooden frames, or it could indicate the foundations of your home are shifting due to subsidence. There could also be an issue with animals or birds damaging the external seals on your windows. 

What happens if I don’t fix misting?

What happens if I don’t fix misting?

If you don’t fix misted windows, the problem won’t go away on its own and it could get worse. The biggest risk for misted windows is the potential for causing damage to the frames. Moisture build up in the frames can lead to rot or breakdown of the materials. This could lead to your windows buckling if the frames can no longer support them.

There is also the issue that your windows will be less efficient if you have a condensation problem. They won’t be as efficient at keeping your home warm, so you might find that your energy bills increase and it costs more to heat your home.

And finally, it’s also not very pleasant to live in a home with misted windows. It will obscure your view of the outside and will also look unpleasant for those outside your home. If you are trying to sell your property, it can make your home look poorly maintained and may impact the value of the property. It will also make the inside of your home darker as light won’t be able to pass through your windows as easily.

It’s not a good idea to ignore misting in your windows and we would recommend fixing or replacing damaged panes before the damage can spread. If you notice it in one window in your home, there is a good chance it could soon be spotted in other windows in your home as the seals will tend to wear down at a similar rate.

How do I know when it’s time to replace my double glazing?

How do I know when it’s time to replace my double glazing?

Most double glazing will last for around 20 years. While some people notice issues with their windows after just 10 years, others can enjoy them for 50 years without complaint. It all depends on the quality of the windows, the standard of installation, maintenance and exposure to extreme changes in temperature.

Misting in your windows is one of the signs that it might be time to replace your double glazing. The presence of condensation typically means that there is an issue with the seals in your windows and the centre of the double glazing is no longer air tight. When this happens, your double glazing will become less efficient.

Once your double glazing stops working efficiently, you might notice draughts around your windows and it might become more difficult to keep your home warm and comfortable. Energy bills may also increase as a result of these issues. It might seem like a small problem, but it can quickly become more widespread.

Closing thoughts on how to fix misted double glazing

Closing thoughts

It’s a good idea to learn more about the signs of misted and blown windows as it will allow you to act quickly at the first sign of a problem. You’ll have a choice between repairing the window or replacing the window panes. 

While repair might be the cheaper option, it is also a temporary fix that is likely to fail again in the future. To prevent this, it would be far better to choose to replace the window pane entirely and start fresh with a fully-functional and properly sealed pane.

If your windows are reaching the end of their life, you might consider an upgrade to modern double glazing or even to triple glazing. This will help to make your home more energy efficient and will make it cheaper to warm your home in the future. New windows can also be more secure and act as a strong deterrent to thieves.

If your windows are older than 20 years old, it might be time to think about replacing them with modern windows. There are lots of double glazing options to choose from and this could be just the thing you need to freshen up the exterior of your home. If you’re thinking about selling soon, this could add value to your property and also increase the curb appear for potential buyers. 

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