Damp/cold patch in living room

[Davidandkeiley]

Hi all, over the past few weeks we've noticed what appears to be large damp looking patch appearing in the middle of the wall in our living room. After having a look today the area highlighted is very cold to touch compared to the surrounding area and also the paint as you can see can easily be scratched off. I've been having a look and noticed that in the loft there is a old flue that connects to a vented roof tile then disappears into the cavity and im guessing that this then used to run in-between cavity then come back out in the living room downstairs. This is roughly inline with the damp patch . Am I right in thinking this could possibly be the cause of our issue if the previous owners removed old gas fire but not blocked of the flue correctly?
Hope that makes sense
Dave

 

[Davidandkeiley]

Just thought of one other thing she did have a couple of stupid Christmas card hangers in this location over the past couple of weeks that hold your Xmas cards but don't think that would of caused this ?