Bubbling plaster

[vizzo]

House dates from Victorian times and has had numerous leaks in various places resulting in the plaster (both original lime and modern gypsum) bubbling and flaking away.
I have hopefully resolved the water ingress problems but still need to deal with the plaster.
Having stripped the plaster off and left the bare brick walls for a few months I need to decide what to do next.
The walls although distinctly drier are not completely damp free if you put one of these cheap meters on them. One brick will produce no sound then the next one an ear piercing shriek possibly due to different porosity of the bricks I guess.

A few questions:
I believe the bubbling of the plaster is caused by salts in the wall. Do these salts magically disappear when the wall is dry or is it that they effectively become inactive unless the wall gets wet again?
How do I know when the wall is dry enough/will it ever get dry enough?
Is there anything I should do to the wall to treat it?

 

[ree]

What wall(s) at what height in the wall are you talking about?

Solid or cavity - rendered exterior - previous damp proofing etc?

Why not read up on similar previous posts and advice? Use search facility.

 

[vizzo]

Thank you for your reply.
Just to clarify - this is not a rising damp/damp proofing problem.
I have read numerous threads (most of which are about rising damp) and I'm not clear on the correct answers to my questions from those threads.
If it's relevant (as its not rising damp) the walls are on ground floor, first floor and second floor. There are both internal and external walls affected. The external walls all have original external concrete render. External walls are double brick solid walls and double skin sandstone with rubble infill. Internal walls are single brick and double brick with infill (the latter was external but is now internal)The walls originally had lime plaster which is covered with modern emulsion. In some places the walls have been partly replastered with modern pink plaster. in some places both lime plaster and the modern plaster have been crumbling away due to the ingress of damp.
The ingress of damp is now solved.

Replastering all the walls is impractical, so it's going to be a bit of a patchup. I have removed all crumbling plaster and the affected bits of the walls have been left to breathe/dry our for about 9 months now.


So back to my question which i'm hoping has a simple answer(!) - I'll phrase it slightly differently:

If there is still some damp in the wall, will it cause new plaster to deteriorate?
Is the potential problem caused by the salts being in the wall or in the plaster?

 

[ree]

Q1. Yes.

Q2. The wall.