Cause of damp around chimney breast in loft conversion

[HouseNumpty]

Hi, is there a common cause of this sort of damp around a chimney breast? It's on the external side wall of a loft conversion in a Victorian semi. Mostly it is at the horizontal/vertical joins but there are some small patches on the face of the chimney breast as well. Thanks!

 

[foxhole]

Chimney not capped and ventilated, chimney in poor condition , lead work etc .

 

[Harry Bloomfield]

1. Flaunching around the top of the chimney
2. Lead in poor condition and leaking
3. Chimney pointing
4. Ventilation of the chimney

All will need to be checked out, by a reputable roofer.

 

[HouseNumpty]

Thanks. I subsequently noticed a green stripe (moss/lichen?) running down the back of the roof to the side of the chimney, which may be related.

Would fixing something like this be a major expense, or is it not possible to tell until thoroughly inspected?

 

[foxhole]

Thanks. I subsequently noticed a green stripe (moss/lichen?) running down the back of the roof to the side of the chimney, which may be related.

Would fixing something like this be a major expense, or is it not possible to tell until thoroughly inspected?

Guess work, may be a simple as a loose tile , but needs looking at.