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Damp Proofing Question
Why do patches of water keep appearing on my walls?
I moved into a house built in 1900 last year and since we have moved in there have been patches of water appearing on a wall in my dining room. The water does not leave a stain and as soon as it dries out it nothing is visible hence why I didn't see it when viewing the house!
The wall is an external wall with no vents. There is an alcove in the wall that I think used to be a window. I have been advised that it is possibly condensation not damp, however it's appearance appears to be connected to rainfall. The patches always appear in exactly the same place.
I really want to get rid of it so I can put furniture against the wall but until I know for sure what is causing the problem I can't!
would think it is a pointing problem,with houses of this age their is usually no cavity and are built using lime mortar,this allows the building to breathe,if it has been pointed or a window has been filled in using a cement based product this can cause internal dampness issues ,as their is no cavity between the brickwork any rain water hitting the external wall can transfer into the internal wall.
Answered 12th Apr 2013
If it was penetrating damp it would leave a stain and would not appear and disappear
this does sound like condensation when it rains there is more moisture in the air which can add to internal moisture problems you need a damp surveyor to come round and check the plaster behind the skim surface to make sure its not penetrating damp if its dry behind the skim then its condensation.
Answered 15th Apr 2013
I agree with plaster works comments. You may have some salt contamination too which will absorb the moisture from the atmosphere. This type of problem produces the symptoms you describe.
A survey and test are the way to go.
Answered 21st Apr 2013