How to Fix Blown Double Glazing

Double glazing provides our homes with exceptional thermal efficiency all year round. Whether it is about keeping your home warm in the winter or cool in the summer, double glazing allows you to use less energy throughout the year. With energy prices currently soaring and only looking to get higher still, it is incredibly important to make sure that your home is as energy-efficient as possible. By investing in double glazing, you’ll be on your way to providing your home with protection against heat leaking and overspending on your energy prices.

Unfortunately, double glazing is not infallible, and once it has broken, you’re going to struggle to maintain that level of thermal efficiency in your home. Therefore it is incredibly important to spot when your double glazing is faulty or blown so that you can address it quickly.

How does Double Glazing become ‘blown?’

Double glazing becomes blown when there is a leak somewhere in the window that has caused the insulating gas, argon typically, to escape and regular air to filter in. This generally occurs through the seal, which is the piece of black rubber that runs around the edge of the glass. As this is the weakest part of the window, this tends to be where breaks can happen.

You’ll know that your double glazing has blown when it starts to mist or fog up, and you cannot wipe it off. You’re getting condensation on the inside of the glass, which is why you can’t wipe it off from the outside. The only way that water vapour from the outside world gets into a double glazing unit is through a leak since the whole thing is intentionally vacuum sealed with the thermally insulating gas between the glass.

How to fix blown double glazing?

Once the unit has blown, you will need to get it fixed or replaced as soon as possible so that you don’t have to suffer from poor thermal insulation in your home for long. Furthermore, the condensation can lead to other issues, such as the build-up of black mould, which can pose health risks and can damage the window even further if not dealt with.

When it comes to how to deal with your blown double glazing, you’ve got a few options in front of you:

  • Have the seal replaced by a professional
  • Replace the seal yourself
  • Have the whole unit replaced

Which is the best option?

While the last option might seem somewhat dramatic, it’s probably the best option to go with. Once double glazing blows, you’ve lost all of the thermally insulating gas that sits between the two panes of glass. So even if you do choose to replace the seal, you’re still going to have lost a key layer of insulation from the inside of your double glazed window.

Replacing the seal yourself is by far the cheapest option of the three and certainly, the one that can be done quickest. Replacing the seal is a relatively easy task for DIY, and there are many guides on the internet on how to do it. You will need a few bits of equipment and a certain amount of know-how to ensure that you don’t break the glass or any other part of the unit during the replacement. This method comes with the lowest recommendation of the three from us. However, it is worth pursuing if you feel it is the best option for you.

Having the seal replaced by a professional is the middle recommendation among the three. If you choose to go this route, you can be assured that the job is getting done right, and you’re still saving money on having the whole thing replaced. A professional will also vacuum out the air between the two panes of glass so that you have a vacuum between them instead of moisture-filled air. It’s not as good as the thermally insulating gas, but if you want to ensure that you won’t have another condensation build-up anytime soon, this is the way.

Having the unit replaced is the best option of the three. When double glazing blows, it had likely reached the end of its natural life cycle anyway and should be replaced completely to reach thermal efficiency levels from before the seal was broken. If you’d like to compare prices for double glazing installers, you can do it right here on our website!

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