We have a parged wall in our living room that is rough, uneven and smells moldy, thanks to the former owner of the house who tried to cover it up with a flimsy wood panel. We suspect they used the concrete (parge) to cover up the original brick wall in our 110 year old house instead of repointing the bricks. The adjoining brick wall in the basement (the floor below the living room) has crumbling brick.
I would like to cover the wall with a natural plaster but not sure if this would be wise given the current state of the concrete wall (the moldy part concerns me most). Should we leave it alone (not cover the wall with natural plaster) or would it be okay to proceed?