Condensation on lintel

21 Nov 2021
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United Kingdom
Hi, I'm not sure if this is in the right place but, i stripped my kitchen/dinning room back to brick when we moved in and the linel condensates to the point were its dripping down the window.

There was foam behind the lintel/under the cavity tray(if that's what it's called) but it's all fell to bits, iv tried to push polystyrene up but failed miserably , I was wondering if I could spray expanding foam up there before plasterboarding over? and if so, would this stop the condensation?

I'm getting a new window and really don't want brown condensation stains running down it like this old window has .

Thanks for your help and time
Last edited:
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How bad is the condensation? Might be advised to post a photo.

You might need to insulate the window reveals too.
Sorry I thought I'd inserted pics and ye I'm pretty sure it condensation because it's still wet even on a dry day, when it's cold out.


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Assuming it is condensation, then spraying some foam or inserting some insulation into the gap won't make much difference, the lintel will still be cold and where the warm air meets the lintel just above the window wont change.
how do I stop it from condensating? I cant i cant put a new window in or plaster board over that if its going to keep condensating
Fit some insulation into the void properly and move the window back, then they'll actually be some insulation between the lintel and the inside.

Or you could fill the gap with some suitable insulation and fit say 30mm insulated plasterboard to the underside of the opening - give that a whirl. Assuming it is condensation. Try ventilating the room more.


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