I'm rehabbing a house my great uncle built in two phases. The first side was a post-war cottage he built himself after coming home from Europe and that section is made of actual legitimate cinder block. The second section is a mid century modern addition built with modern style concrete block about 10 years later. The concrete block is in great shape, but the cinder block is spalling where bigger lumps of cinders are near the surface. We're insulating the house with InSoFast panels so for most walls this is not an issue - it's not deep enough to cause structural problems, just cosmetic. My question comes down to the wall that used to be an exterior wall but is now an interior wall on the addition. That interior wall is spalling like all the others, but this end of the house has exposed concrete block painted for a certain look. My aunt will be moving in, is an architect, and rather likes the brutal appearance and wants it saved, so we're avoiding just coating the house in drywall where it can be avoided. There's not alot of information that I can find on true cinder blocks, so I can't tell if this is somethign that can be spot patched, would require parging, or if parging will just spall again in a few years because of the underlying cinder block being weak on the surface. I'm not averse to drywalling this wall in the end, I just want to explore my options so if I go that route, I can explain the choice to my aunt. Thanks for any insight the TOH hive mind is able to provide!