Blocked up fireplaces in old house converted to flats

[Gary111]

Hi, I have a house built around 1900 split into 3 small flats on three levels getting some damp on the chimney breast, to the left .

the fireplaces are blocked up, but there is a small airbrick on the outside of the chimney, it has been capped.

The survey stated that air bricks would be needed where the fireplaces had been blocked, however I feel this may cause noise to travel between the flats and cause annoyance.

I was wondering whether it would be worth putting an airbrick in maybe just the lower one ?
Or lower and top ones ?

I also wondered if painting the outer wall of the chimney with thompsons water seal would help prevent water ingress through the outer wall ?

Thanks

 

[vinn]

Each fireplace has its own flue - each flue is independent & runs from its fireplace up to its chimney pot or terminal on top of the chimney stack.
Sound transmission up the flues is unlikely or minimal.
Each fireplace in the house should be opened up and swept, and, as its in flats, each flue should also be smoke tested.
Venting each blocked off fireplace is the best practice.
If the flues are not swept and vented then there's a strong possibility of sooty chemicals penetrating onto decorated surfaces in the rooms. The chemicals attract damp.

Photos of your issues would help esp. photos of the damp signs?

 

[Gary111]

Thanks for that, I have just painted over the damp, it's worst in the bottom flat to left of fireplace, causes paint to bubble off, top flat has similar patch on ceiling near left of fireplace also.

If I put a vent in the fireplace would it just be a plastic one maybe the size of two bricks, ie doesn't need to provide support strength ?