Paint Blisters on Wall. (With Photos)

[Southhill]

Hi,

I've had this recurring problem for some time. Paint blisters appear on a corner pillar in our sitting room. I've tried painting the exterior side of the wall with silicone brick seal, then scraped off all the blisters, painted the entire wall with Zinsser BIN, filled any damage, then repainted the whole wall. The blisters re-appear after a few weeks.

Someone told me it could be efflorescence, so I tried the wine vinegar solution and repainted but still no luck.

This side of the flat does get a lot of rain and the flats above have a similar problem on the same wall.

I'm attaching some photos.

Any ideas gratefully received.

Geoff

 

[footprints]

Does look like efflorescence could be leakage into the cavity from above if flats above have the same problem, condensation from the window sill running down there or possibly condensation if furniture is normally in front of it although as a rule then you would have mould too.

 

[opps]

As above, I suspect that the problem might be the roof or the exterior wall of one of the flats above yours. Can you see any obvious cracks in the brick pointing.

 

[sparkwright]

There may well be rubble in the cavity contributing to this as well.