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White bubbles/powder on internal bedroom wall
Need some advise please - I have just had a full new roof as have damp probs. I live in a terraced house and our bedroom wall adjoined with next door has white bubble and white power on it, slightly above the middle of the wall. Next door has been empty for around 18months and it is near where their chimney is. Is this because house has been empty and no heating on, have been bleaching it, will it dry out if they put heating on for an hour each day? Will I need to re-plaster? Also is this dangerous if breathed in as my son is severe asthmatic hence having new roof.
If you have had some damp problems then the white powder will probably be hygroscopic salts you will need to hack off these areas and rerender with sand and cement with salt inhibitors ,the salts do not generally become air-born so should not cause a problem,google hygroscopic salts and you will find more info
Answered 11th Mar 2013