I'm converting our former boiler room in the basement into a home office. After 60 years of use, the ceiling and walls were not exactly clean, and to remove the soot, I've scrubbed with soap and rinsed off with water, the advantage of having a faucet + drain in the room. I haven't used a pressure washer, just a regular garden hose with low pressure.
The walls and ceiling are mostly covered with paint of unknown type (not bare concrete), and it's sticking annoyingly well, so my prospects of removing it are quite non-existent.
The interior walls have lots of holes from plugs, and to achieve an even surface, I will skim coat as thinly as I can get away with.
How long should I wait to start spackling after the walls have been rinsed? It is not noticeably damp in the room.
