Hi,
My first time here.
I have a problem which recurs every year. Paint blisters on an interior wall. I've painted the exterior part of the wall with silicone brick sealer, scraped off all the blisters, painted the whole wall with Zinsser BIN, filled the damaged areas and repainted, but the blisters re-appear after a week or so.
It's just on the pillar in the photos and not on the pillar on the opposite side. This side does get a lot of rain and the same wall in the flats above have the same problem.
Someone told me it could be efflorescence, so I treated with wine vinegar solution, sealed and repainted but still not solved.
Any thoughts?
Geoff