Live plaster on internal wall

[dulciepreston]

I have an exposed solid external wall to my bedroom which is pebbledash rendered on the outside (1890’s house). The solid wall appears to suffer from moisture ingress as the plaster has become live in a few isolated areas over time. I have removed all the live plaster down to the brickwork which always appears dry and I am now deciding on what to do. It is not evident where this damp is coming from, although not being much it just causes minor damage to the decoration. As I do not believe it is possible to eradicate all moisture in a solid wall, the options to me appear to be:
1) sand and cement scratch coat followed by a finishing coat
2) drylining the wall with battened out plaster board.

Grateful for any advice from any expert prepared to contribute.

 

[stevethespreader]

if your brickwork appears dry then i would guess that the damp you think you have may be condensation from inside