Damp Proofing

Failed damp proofing of chimney breast with salts coming through

Anonymous user 15/03/2024 - 2.46 PM

Hi all, I moved into a house which turned out to have significant damp around the bottom of a blocked off chimney breast in an internal wall. A contractor came round and capped off the chimney breast, stripped back the plaster, bricked up the fireplace (it had only been covered with plasterboard), gave it one layer of tanking slurry and skimmed it the next day. This hasn't worked and weeks later the salts were coming through again. As it stands, what I think needs to be done is make sure the capping off was properly ventilated, strip back the contaminated plaster and tanking, add an air brick or vent to the chimney breast, do a coat of salt inhibitor, then two coats of tanking with drying time, then finally reskim! Is this the best course of action? Is there any part of this which isn't necessary, or anything you think needs to be done to address the problem?