Hi All,
We recently moved into a barn conversion (converted 2008) and noticed that there was some damp on one internal wall coming through in patches. It soon became clear this was where the dab and dot was. I removed a small section of plasterboard to reveal an old wall behind (the barns were built in 1860) so this is 150+ years old, lime mortar old bricks etc. This wall would have been exposed to elements to a fashion and all the usual cow excrement, water etc. in a cow shed so is more than likely saturated.
I've read that you shouldn't dab+dot any walls of this nature because the salts in the mortar/brick migrate through the dab+dot and are hygroscopic causing moisture to be attracted to it - hence the dark patches!! These walls like to breath!?
I understand one solution is to render the brickwork with a breathable render/plaster? I was also wondering if an alternative solution would be to fix plasterboard to the wall with metal fixings? This would prevent salt migration.
Pics below. The damp is as high as 2m so pretty sure it's not a rising damp problem and that the house has a damp course. I have been monitoring humidity in this area of the house and when it's 60% the damp patches are numerous and when it's 40% they nearly disappear! So does seem related to the hygroscopic salt theory. Dehumidifier doesn't prevent it....
Any help/guidance is appreciated.
Many thanks![/img]
We recently moved into a barn conversion (converted 2008) and noticed that there was some damp on one internal wall coming through in patches. It soon became clear this was where the dab and dot was. I removed a small section of plasterboard to reveal an old wall behind (the barns were built in 1860) so this is 150+ years old, lime mortar old bricks etc. This wall would have been exposed to elements to a fashion and all the usual cow excrement, water etc. in a cow shed so is more than likely saturated.
I've read that you shouldn't dab+dot any walls of this nature because the salts in the mortar/brick migrate through the dab+dot and are hygroscopic causing moisture to be attracted to it - hence the dark patches!! These walls like to breath!?
I understand one solution is to render the brickwork with a breathable render/plaster? I was also wondering if an alternative solution would be to fix plasterboard to the wall with metal fixings? This would prevent salt migration.
Pics below. The damp is as high as 2m so pretty sure it's not a rising damp problem and that the house has a damp course. I have been monitoring humidity in this area of the house and when it's 60% the damp patches are numerous and when it's 40% they nearly disappear! So does seem related to the hygroscopic salt theory. Dehumidifier doesn't prevent it....
Any help/guidance is appreciated.
Many thanks![/img]
