Plastering & Rendering

How to fix flaking paint and white powder on newly painted plaster?

Anonymous user 23/02/2024 - 2.43 PM

Last year a blocked gutter resulted in damaged plaster on an outside wall in a mid terraced 60 year old property in an upstairs bedroom. The gutter was cleared.All plaster was removed from the entire wall and it was replastered by a tradesman. I let the wall dry for three weeks and repainted with emulsion ( 3 coats).In the last few weeks a bit of flaking has occurred, but also a white powder had appeared in patches. The wall is apparently dry, the powder brushes off easily. I cleared it all off, repainted, but within 3 weeks the growth has re-appreared. a previous question reply mentions "efflorescent salts. The wall is not damp.Is there something on the market that I can use to "seal" the already painted wall? what would happen if I wallpapered over it?