The initial action for the repair of your ceiling is to remove the old whitewash and plaster. This is one of the most complex and laborious processes. Previously, the old plaster was examined and tapped, checking for strength, in the places where it was chopped off, it was replaced by a new. Or used another option, washed the old surface with soapy water, and then a solution of ammonia, also used a solution of soda, and at the end they completely washed off with clean water.
How to remove fat spots from the surface of the ceiling
