Chimney & Fireplace

Damp on top of chimney wall

Anonymous user 23/02/2024 - 3.00 PM

I hope someone may be able to shed some light on this. Our house is a 1930s detached house. There are 4 chimney breasts (2 up, 2 down) and only one of them has a working fire (in the downstairs back reception room). It is a gas fire and hasn't been used since we moved here last April. On the chimney breast of the gas fire, a damp patch has appeared over the last few months at the top right. The damp patch is currently about 30cm high and seems to be spreading very slowly downwards and leftwards. I have no idea if using the fire would help to dry it out but we would rather not as we have very young children and the house is quite warm with the central heating anyway. Would anyone know what we need to look for to get to the cause of the damp or what tradesmen we can call on to investigate? I would really like to paint the room soon so would like to sort this out as soon as possible. Many thanks in advance of your response(s).