Problems With 8 Month old Plaster Creating Wall Rash

[jammers]

Hi Guys,
I have a sort of wall rash breaking out - thats about the best way to describe it.
I have linked pictures to my drive, link here;
https://photos.app.goo.gl/EPaPF4JTOJahsALB3

So, the area was re-plastered about 8 months ago and in the last 2 months all these patches have been appearing, it would appear at first they are water ingress related as they are around a door and by a window but they have also broken out on a middle wall. Bizarrely, it would appear it hasn't spread to the new plasterboarded walls, just the old ones???

Ideas, thoughts please?

Thanks
James

 

[EFLImpudence]

Not really an electrical problem.

I'll get you moved to the building forum.

 

[footprints]

Was the plaster dry before painting, did you use a breathable (contract) paint for new plaster? Looks like damp plaster drying out to me.

 

[jammers]

Thanks for replying.
The plaster was dry, if I remember, I left it for a week or more before and used a breathable paint for all coats.
It just seems bizarre in the places its breaking out in.?

 

[tony1851]

Salts migrating from the brickwork?

 

[jammers]

It looks like salts in a couple of the areas, it was previously tiled - would that have a bearing?

Also, if its salts whats the cure?

Thanks for all the replies ...

 

[^woody^]

If it's salts, then its damp pushing or drawing them out.

If it was damp before and all the plaster was not removed and the wall stabilised (ie just skimmed over), then its the previous salts coming through the skim coat.

 

[jammers]

whats the best way to deal with this would you say?

 

[^woody^]

First you need to confirm that there is no penetrating damp.

Then determine that its not a cold spot (thermal bridge) causing condensation to form on the cold part of the wall.

Then, if it is just due to old plaster, hack it off down the the bare wall plus 150mm past the occurrence, brush on a stabilising solution or salt neutraliser, then re plaster and re skim.