How to prevent cold air coming in from window?

Question

I’ve got a aluminium single glaze sliding window, which brings in a cold draught but is also just cold in general around the window. I’ve looked at different solutions and want to add some weather stripping and possibly some way of insulation. I’d still like to be able to open my window a couple minutes a day so i don’t think i can diy it because i like the light coming in too.

I’m just a bit confused on where the weather stripping goes. I’ve taken the window off and including a lot of photos from different angles, the first are the frame with the sliding window off, then the window that’s off and then how it looks when put back in

If anyone can help me out thanks heaps:)

MitchellMc · Answer

Hi @sophie1199,

Thanks for taking the time to remove the sash and provide so many photos. They make it much easier to see what you're working with.

With older aluminium sliding windows like yours, there are generally two sources of draughts:

* Air leaking around the sliding sash where it meets the frame.
* Cold being conducted through the aluminium frame itself. Unfortunately, no amount of weather stripping can completely stop this, as aluminium is a very effective conductor of heat.

The first thing I'd check is whether the original pile seals (also called brush seals or weather pile) as still of the original thickness as sealing drafts. These are the fuzzy strips that run around the edges of the sliding sash and seal against the frame. Over time they become worn, flattened or can even fall out, allowing cold air to pass through. From your photos, they look like they may be worn, although it's a little difficult to tell.

If they do need replacing, I'd start there before adding any additional weather stripping. Adhesive foam weather strip is generally not suitable in the sliding tracks, as it tends to create too much friction and can stop the window from sliding properly.

If you can still feel air coming in after replacing the pile seals, you could use a thin self-adhesive foam strip on any fixed sections where the sash closes against the frame, provided it doesn't interfere with the window's operation.

To improve insulation further while still allowing you to open the window each day, you could also consider:

* Installing heavy curtains with a pelmet to reduce heat loss.
* Applying a clear insulating window film during winter, which creates an insulating air gap while still letting light through.
* Fitting a secondary acrylic glazing panel using magnetic or removable fixings, which can be taken off if required.

Could you also let us know whether the draught seems to be coming from the top, bottom, latch side or the meeting rail where the two window panels overlap? That will help us narrow down the best place to improve the seal.

You might also find these previous discussions helpful, as they cover similar issues with draughty aluminium sliding windows:

* How to add weatherstrips to sliding windows? by @jorjmorris Where a member was replacing the original felt/brush seals after removing them for painting. 
* How to seal aluminium sliding door and window frame? by @imarshallwidjaj Which discusses tracking down draughts around aluminium frames and selecting suitable weather seals. 
* How to make aluminium sliding windows draught and noise proof? by @foxhound Which looks at reducing both air leakage and noise through sliding windows.

Please let me know if you have any questions.

Mitchell