the brickwork looks as if a window or something has been bricked up in that wall. Do you know what happened?
No I don’t unfortunately. But it definitely looks like someone fixed something here before. Btw, the pictures of the bedroom are on first floor.
you say that a "treatment" for "rising damp" has previously been tried, so obviously there is a long-term source of water making that wall wet. Please stand back and photograph it from ground to roof. "treatment" is usually tried to hide the water without correcting the source. Your chemical potions are the same. How close is this "rising damp" to ground level?
the rising damp treatment was done the week after I bought the house based on the building survey. They removed plaster inside up to 1.2m above floor level, did some injection in brick joint, tanked the wall and re-plastered. The living room marks as seen on the picture are starting at around 1.6m above floor level and I have nothing below. I believe these were hidden before I bought the house and we’re not detected during building survey. I suspect mortar and brick issues but I am yet to go in my neighbors garden to check that out.
Once the outside wall is “fixed” how should I go about fixing the plaster in the inside?