Painting over efflorescences

[ijakk]

Hi all, I have a utility room to paint, the outside wall of this room is actually underground, they have had continual problem with this room and last year had the outside wall which is underground, dry lined with insulated plaster board. Not long after we painted it efflorescences and dark patches appeared on the surface and the paint began to flake of in patches. The builders returned and has hopefully sorted out the moisture problem, there is still efflorescences in places, what is the best way to deal with these areas, brush off, wash down and then perhaps alkaline resistant primer????

Cheers

Rich

 

[opps]

The zinsser cellar paint might be a better option

http://www.zinsser.com/pdf/WaterTiteBooklet.pdf

It claims that it deals with efflorescence as well as damp and can even be applied to damp surfaces