Efflorescence

[vicjay0147]

The efflorescence on two of our internal walls (the only original brickwork in a 19th century cottage) has been so bad that we have had one wall replaced completely and the other one has had a new membrane inserted. The first wall is no longer a worry, but the second still causes me some concern as some of the bricks are still very 'salty' - although I have chopped out the worst culprits. I have left the wall for several weeks without plaster, and have been using a dehumidifier to speed up the drying process, and it appears to be dry now, although the salts are obviously still there and visible on the surface of the bricks.
Is there anything else I can do to minimise the possibility of salt penetrating the new plaster when it is applied? I would have thought that drying the bricks would have been enough, but I am not 100% convinced. What about sealing with PVA for example, or using a salt inhibitor?

[leebwk]

Hi

brush off the salt with a stiff brush not wire then on your backing coat i would use sulphate resisting cement

[vespa]

Hi

brush off the salt with a stiff brush not wire then on your backing coat i would use sulphate resisting cement

SRPCs are usually used for underground work.

[vespa]

The efflorescence on two of our internal walls (the only original brickwork in a 19th century cottage) has been so bad that we have had one wall replaced completely and the other one has had a new membrane inserted. The first wall is no longer a worry, but the second still causes me some concern as some of the bricks are still very 'salty' - although I have chopped out the worst culprits. I have left the wall for several weeks without plaster, and have been using a dehumidifier to speed up the drying process, and it appears to be dry now, although the salts are obviously still there and visible on the surface of the bricks.
Is there anything else I can do to minimise the possibility of salt penetrating the new plaster when it is applied? I would have thought that drying the bricks would have been enough, but I am not 100% convinced. What about sealing with PVA for example, or using a salt inhibitor?

The best way to sort this problem out would be to dry line it.

[vicjay0147]

Thanks for such a quick response. Will dry lining with plaster board stuck directly onto the surface of the bricks be OK, or could the salt still mark the plaster/decoration. My previous experience with dry lining, when there have been concerns about continuing damp encouraging the salt, has involved leaving a gap.

[vespa]

Thanks for such a quick response. Will dry lining with plaster board stuck directly onto the surface of the bricks be OK, or could the salt still mark the plaster/decoration. My previous experience with dry lining, when there have been concerns about continuing damp encouraging the salt, has involved leaving a gap.

Refer to your previous experience