Damp Proofing

How to paint onto chimney breast with salts coming through

Anonymous user 23/02/2024 - 3.36 PM

So, I've had a wall plastered in a bedroom in my house which used to be where an airing cupboard, water tanks etc used to be. Half of the wall is a chimney breast, which was capped and closed off many many years ago. After removing the airing cupboard, there were 2 or 3 areas of both the side of the chimney breast and the wall next to it where there were salts from the bricks coming through which had flaked and made the old paint sandy and bubbly. Once scraped away, the plaster underneath was bone dry, it was simply the salts escaping from the chimney breast. So, fail one - the plasterer replastered with normal gypsum plaster. I now understand it should have been a type of renovating plaster to allow the bricks to breathe. Second fail - I have purchased vinyl matt paint to use on the wall which I understand also doesn't allow the wall to breathe. I'm concerned that the salts will come through again. My question - is it too late to worry about the salts coming through considering gypsum plaster has been used already, so using vinyl matt paint won't make any difference? Or will using flat matt help the wall to breathe? This is all based on whether the salts in the brick MAY come back through again... Thanks!