Hi, I have a mid terrace built in 1900. I have damp patches and I'd like help in trying to work out if I have condensation and water ingress from the chimney (or maybe rising damp??) or just condensation.
Here's a diagram of the affected areas with some close ups below View media item 80872
The chimney breast in the living room feels damp to touch, but only in a small area on the corner (area B & C in the diagram). It was wallpapered with lining paper about 2 years ago and it feels like the paste never dried. Consequently the paper has peeled off. There was no mould, just dampness and the paint on top of the lining paper bubbled and developed white crystals (hygroscopic salts?). View media item 80866 View media item 80867 View media item 80868
The salty crystal stuff is now developing in patches like this in the alcove
View media item 80869 View media item 80876
The salty crystal stuff is confined to the alcove just above the skirting on areas . But the wallpaper is still firmly attached and the wall doesn't feel damp like it does on the chimney. The alcove is formed by an internal wall and the salty stuff is developing there on the living room side of the wall (Area D) . On the dining room side (Area E) a damp stain has appeared. No salty crystal stuff is in this patch. To my untrained eye, the dining room patch looks like condensation. View media item 80870 View media item 80871
The neighbours say they don't have damp on their walls.
Would condensation cause the development of the salty crystal stuff and cause the paint to bubble?
The rooms affected have timber floors and there is a cellar underneath both rooms. The cellar is 7 feet deep so I wouldnt expect damp to be able to rise from the cellar into the first floor, especially since the walls affected are internal walls. There are no water pipes or other sources for water to be leaking from. The walls are all internal so no guttering/pointing to be repaired.
All i can think is that water is in the chimney, or that the hygroscopic salts are attracting condensation. The chimney has one of those rain cap things over it so air can get in but not rain, and the fire place is open so air should be circluating (albeit not as well as in the good old days when the fireplace would be used daily). Could the problem be solved by knocking the plaster off the affected walls and replastering, and dealing with any internal condensation (the relative humidity is usually around 50-60%).
When i run a dehumidifier the wall feels dry to touch, but when i turn the dehumidifier off the wall soon gets wet again.
If water was getting in the chimney would i be seeing similar patterns in the room above the living room. Currently that room is fine with no signs of damp what so ever.
Any help in trying to identify the cause of the dampness would be greatly appreciated.
Cheers
Here's a diagram of the affected areas with some close ups below View media item 80872
The chimney breast in the living room feels damp to touch, but only in a small area on the corner (area B & C in the diagram). It was wallpapered with lining paper about 2 years ago and it feels like the paste never dried. Consequently the paper has peeled off. There was no mould, just dampness and the paint on top of the lining paper bubbled and developed white crystals (hygroscopic salts?). View media item 80866 View media item 80867 View media item 80868
The salty crystal stuff is now developing in patches like this in the alcove
View media item 80869 View media item 80876
The salty crystal stuff is confined to the alcove just above the skirting on areas . But the wallpaper is still firmly attached and the wall doesn't feel damp like it does on the chimney. The alcove is formed by an internal wall and the salty stuff is developing there on the living room side of the wall (Area D) . On the dining room side (Area E) a damp stain has appeared. No salty crystal stuff is in this patch. To my untrained eye, the dining room patch looks like condensation. View media item 80870 View media item 80871
The neighbours say they don't have damp on their walls.
Would condensation cause the development of the salty crystal stuff and cause the paint to bubble?
The rooms affected have timber floors and there is a cellar underneath both rooms. The cellar is 7 feet deep so I wouldnt expect damp to be able to rise from the cellar into the first floor, especially since the walls affected are internal walls. There are no water pipes or other sources for water to be leaking from. The walls are all internal so no guttering/pointing to be repaired.
All i can think is that water is in the chimney, or that the hygroscopic salts are attracting condensation. The chimney has one of those rain cap things over it so air can get in but not rain, and the fire place is open so air should be circluating (albeit not as well as in the good old days when the fireplace would be used daily). Could the problem be solved by knocking the plaster off the affected walls and replastering, and dealing with any internal condensation (the relative humidity is usually around 50-60%).
When i run a dehumidifier the wall feels dry to touch, but when i turn the dehumidifier off the wall soon gets wet again.
If water was getting in the chimney would i be seeing similar patterns in the room above the living room. Currently that room is fine with no signs of damp what so ever.
Any help in trying to identify the cause of the dampness would be greatly appreciated.
Cheers
