Damp Proofing

Damp chimney - venting from outside

Anonymous user 9 March 2024 - 3.26 PM

Not sure if this is really a damp proofing question or general building but I'll give it a go here! I have a Victorian terrace with a dis-used chimney breast at the back. The bottom of the chimney is in the kitchen (with kitchen cabinets installed against it) and the upper floor is the bathroom which is tiled over with a shower cubicle infront of it. There are definitely signs of damp, particularly in the kitchen where there is a musty smell behind the kitchen cupboards and signs of damp on the plaster on both sides (what was the outer wall is now within a single-storey lean to extension). In the bathroom, there are some minor signs of rust around the corners of the chimney, and condensation is often visible. My first port of call would be to get a vent installed at the base of the chimney in the kitchen. Its a bit awkward to check because of the kitchen cabinets but I can't currently see one. I wonder whether this would help with the bathroom, as presumably that was a separate flue back when the chimney was in use and a vent at the base wouldn't help with the ventilation in the other flue. But, I need some work doing to the lean-to roof and a roofer has suggested they could install two vents from the outside into the flue. I assume this would then provide ventilation to the upper part of the flue in the bathroom, though nothing down to the lower part in the kitchen. I'm wondering if this is a feasible option? How would they know where the flue runs, and what would happen if the flue is lined and they need to break through this liner to install the vent? Very few houses nearby seem to have vents on the outside. Secondly, how might I tell whether either of these options had been successful? The plaster in the kitchen is already damaged and it is hard to tell whether its getting worse.