Salt deposits on internal walls.

[GCE]

Hey all, hoping for some advice please.
I live in a first floor flat that used to be an outbuilding, stone walls as far as I'm aware, not sure of the type of plaster (I've never been told about the property itself) usually very cold inside. The property has been in my family for a long time, it is very old, but has been a home for at least 30 years, and a pub before that. I remember this happening to the walls when my grandparents lived here when I was a child. My grandfather did a lot of the work itself, a lot of which has needed to be redone professionally (he did too many quick fixes it seems). I have lived here for over three years and this is the first time it has appeared.
I've been away from my property for some time so it has built up. It seems to be salt deposits that have dripped down the wall from some pretty bad cracks. Not sure if I should just clean up and re-plaster, or if it needs a more thorough job.

Thank you in advance,

G

 

[KenGMac]

GCE, good evening.

Are the cracks in the posted images "concentrated around the window?

in image 2 the main horizontal crack may??? be following the upper line of an old timber lintel???

Question? what state is the external wall surface in? any cracks / openings / external cracking mimicking the internal crack ?

In the last image posted above, the vertical crack, does this [vertical] crack commence at the end of the horizontal crack?

There is a possibility that if all the cracking is concentrated around the window head, then the timber lintel in this area may be severely compromised and has been attacked by wood rot, the wood is now holding water and leaching the water into this inside of the property?

Ken.