Damp on chimney breast?

[noob2diy]

Hello all

My first post here so here goes!

Just bought and moved into a 1900 mid terraced property, lots of work to do on it, however im puzzled by what I think is damp on one of the downstairs chminey breast walls (same chimney breast is ok upstairs). the wall is painted a dark colour, however at about face height (dry above and below this), for about a 1.5m square is a darker stain/damp (cold to touch but not wet like other damp patches are in the property) The staining looks to mimic the pattern of the bricks (it is plastered and paper lined).

I'm unsure if chimney is useable, it has a log burner in it, and the inside of the breast is open (i.e no surrounds etc) and looks to of been recently pointed.

N.b All other areas of damp in house are due to faulty guttering/ condensation as usual!)

Any thoughts appreciated.

 

[Richard C]

Damp patches are usually a result of poor ventilation allowing condensation to form or rain ingress from above, does the pot have a rain cap fitted? Many flues in older properties do not go straight up but have quiet an obtuse dog leg on the ground floor, around the height you say; if it hasn’t been used for some time & there is no rain cap or the chimney pointing is poor that could be the problem. If the flue isn’t lined & in poor condition internally it could be condensation/staining from inside the flue seeping through the brickwork mortar joints.

It does sound like your going to need some work doing, I would get the fire installation & flue checked by HETAS registered sweep or fitter before you try using it.