How to seal a leaking window

We all spend a lot of money on our homes. In winter one of the highest salary guzzlers is heating. For that reason, it makes sense to ensure that our homes don’t lose excessive energy due to air leaking from windows.

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Heat often escapes from where parts of the window join, where it reaches the outer rim and when it makes contact with the wall. Professionally fitted windows with double glazing in Gloucestershire are not likely to give these problems. However, older windows can be problematic. Leaks can be located by burning an incense stick near potential weak spots. Spurts of smoke indicate a leak.


Heat is lost where there are gaps between the window, the frame and the wall. Caulking is a fairly simple solution. This will seal the gaps and prevent any more heat loss.

If this does not solve the problem, it’s best to get advice from experts. Companies like Firmfix offer double glazing in Gloucestershire and can give you professional advice on how to make your windows more efficient.

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Expanding mousse

If you want to find a more permanent solution, expanding mousse can be applied to waterproof and air seal your windows. The inner or outer window edge trimmings need to be removed to do this. Although you are just doing a repair job, it might be worth reading to familiarise yourself with the building regulations when it comes to replacing windows.

Firstly, dislodge the trimmings on either the inner or outer window. Not both. Now, spray the expanding mousse into the gap. Don’t worry if it is overflowing. Be sure not to touch the wet mousse. Only, after quite a few hours, will the mousse be dry and can be trimmed of the excess. Finally, you can put the trim back in the opposite order from which it was removed.

Worn out weatherstripping

For this, the moving part of the window will most likely need to be removed for you to establish where the weatherstripping is. Hardware stores have double sided weatherstripping tape available. Take a sample with you when you go shopping for it to show the salesperson or a photograph of the old weatherstripping. Sometimes the product will require an adhesive spray. They are generally very easy to apply.

Sealing leaky windows is a great way to save on heating bills.