Creating holes into sealed chimney - alternative to airbrick

[lneville]

We have a problem with mould on an external wall of an upstairs bedroom. There is no airbrick in the wall and the windows do not have that feature where there is a small air gap even when shut.

So, we considered installing an airbrick in the wall, but then had an idea for a simpler/cheaper option. But would it work?

There is a chimney shaft on an inside wall. The fireplace is completely sealed up. Presumably the shaft is still open at the top - at the chimney itself. The idea is to drill holes through to the chimney shaft, either through the skirting board, or at ceiling level.

Would that be as good as an airbrick to the outside, or are there any problems with this approach?

 

[masona]

First of all, check the chimney lead flashing on the roof is okay before you do anything

 

[foxhole]

The chimney should be vented, you can use low level thru the skirting if you wish but the bedroom could do with a wall vent as well if you have mould.