Help with damaged plaster walls
I wanted to solicit advice regarding the plaster wall in one of our closets. It is directly below the chimney, and about a year ago I started noticing efflorescence (i.e. a powdery substance) on the walls. I left it for a while and noticed it wasn't getting worse. Today I decided to start scraping it off. Of course loads of paint and other things started coming off.
My house is a brick 1920s home. I'm curious about this particular wall, because I've noticed underneath the plaster is a concrete substance. This is an exterior wall, and the other exterior walls we have explored (for various reasons) are plaster directly on brick. This one seems different. Can anyone clarify what the make-up of the wall would be - brick, cement, and then plaster?
You can see in the upper right hand corner how the scraping led the plaster to start to crumble off. My question is, should I keep on going with that and take off any loose plaster? It is likely A LOT would come off.
I've also notice a slight amount of black powdery mold where the wall meets the ceiling. Should I entirely remove the gobs of who knows what (paint, spackle, etc. etc.) that are between the wall and the ceiling. I'm worried that whole area might have mold.
I guess my question is - how much effort should I put into it, in light of the fact that it is in a closet? It is quickly becoming a huge project, but I also hate to do things half way. Because of moisture (which of course I will fix) the plaster is just shot. Do you think I could fix it myself or should I just hire someone?
I have other cracked plaster elsewhere in the house that needs to be fixed (and not by me, since it is so visible). I guess I could just throw it on the pile, but the fact that it is in a closet makes me think perhaps I could fix it myself.
Any thoughts on the construction of a plaster wall in the 1920s and what you would do in this situation is much appreciated.