How to fill in an old chimney - and fix a damp problem

I have an old chimney stack up from the kitchen and through to the bathroom. The kitchen stack part has already been removed (before we moved in), the bathroom stack is still there, not ventilated and was - i think - responsible for a big damp patch coming out on the adjoining bedroom wall. I broke the stack open to try and fix the damp problem. It was bone dry but bricks covered in Soot which apparently sucks the moisturein and through the wall.

So I need to fill it in and seal it off. It is part of the external wall and the back wall of the chimney is now only one brick width thick. We have solid non-cavity walls - 2 bricks thick.

I am thinking to use poly beads, then board it off. My dad says brick it up..

So 2 questions.

1. which method is best/necessary to fill it in?
2. do i need to scrape off the layer of Soot before filling it in? or will filling it in stop the damp air being sucked through?

Pictures -



Read more: //www.diynot.com/diy/threads/removing-and-filling-in-a-small-chimney.461169/#ixzz4BZQSTlyn

Why not remove the chimney breast in the bathroom, & square the corner off but first post a photo of the outside stack.
The soot is removed by wire brushing and painting on two coats of SBR and then 3:1 sand & lime rendering.
search on this forum for any of the above subjects.

Thanks for the advice, very useful.. . Further info -

There is no outside stack - it is all interior. I have attached a quick drawing as photos often dont give enough detail.


So I will wire brush the soot, paint with SBR. After that I will be left with half an empty clean chimney stack. The only remaining problem is what to do with this, as it is only one brick thick to the outside.

I need to corner off this, so the wall runs flush. Is it ok to just board it up and then fill it with Poly beads (and cap it). Or whether it needs to be bricked up..?

The second coat of SBR is rendered while still tacky. The render will blind any soot residue from bleeding through.
You can then brick up the gaps where the chimney breast was. I assumed that you would understand this.
There's absolutely no point in leaving the chimney breast in.
Dont make work and possible future difficulties for yourself by filling with beads etc.
You are confusing the chimney breast and the stack. The stack projects above the roofline and has pots on top. A photo please.
Have you been above the bathroom ceiling and examined the chimney breast up there? A photo please.

Ok, thats clear now
There is no stack on the roof, it was removed years ago I imagine, and there is no chimney breast above the bathroom ceiling. It ends where the roof is.
I will brick it in after having cleaned and sealed it with SBR. Hopefully I will be posting updated photos here soon.