Where plaster has to be renewed because of contamination with hygroscopic salts, it is vital that a special salt retardant additive is used to hold back any residual salts while still allowing the passage of water vapour.
Standard plasters such as Carlite should not be used as many have hygroscopic content and failure to follow this instruction is the most common cause of continuing wall dampness after a remedial dpc has been installed.
The recommended method is illustrated below:
Where necessary, we can either undertake the re-plastering as part of the remedial damp proofing contract or supply our special DryWall Salt Retardant additive for the client’s plasterer to use in a sand and cement render.
Where there are steps in floor level, we recommend applying a waterproof slurry coat to prevent moisture ingress through masonry below the level of the remedial damp proof course.