Damp Proofing

Efflourescence in Brickwork - can we damp - seal and then plasterboard directly?

Anonymous user 15/03/2024 - 2.31 PM

We have an outbuilding with painted brickwork. We want to turn it into a fully functional room and plaster over the brickwork (using insulated plasterboard) to make it a bit warmer and cosier, and usable as an extra guest bedroom. HOwever, the paint on the bricks is flaking off badly, and there is kind of fluffy stuff coming through, the same colour as the paint. Am I right in thinking this is efflourescence/salt comign through the brick? If so, would it be ok to sand this all off, then paint it with, e.g. ROnseal Damp Seal, (although we were advised to use bitumen paint by a friend?), and then plasterboard directly onto this (dab & dot)? We are going to use well insulated plasterboard. Or should we be treating the bricks with something else? There's no obvious cause of damp (except in one corner but that's been removed and sorted), I guess it's just due to teh room being left empty with teh heating off and it's got quite cold in there. I think?! Any advice would be amazing, thank you! Sarah