Working on this job at the moment,what a bodge,they didn’t even put knoting solution on wood.The ceiling was powdery when I checked with a wet finger,so I new there was going to be a problem.When I started removing loose paint a fair bit came off,i cleaned the ceiling with krudcutter,then scraped all loose paint off,and DustBuster to remove dust.Then I applied alkali sealer,but it lifted in two small areas so will scrape back and spot prime.I would like to hear people recomened sealers,even tips on dealing with this situation,my lesson was it may have been better to see the ceiling in good light,but never less any help appraited.I advised customer to do walls with the sealer as well,when the job is finished I am going to use the pictures on a advertising board before and after,what saddens me the guy only had it done a year ago.For topcoat we are using zinnerser permawhite,any other recomendations.
Why are you sealing it though? It looks like bare plaster so presumably it wasn’t primed/misted before the top coat went on hence the lack of adhesion and I would think you could scrape the lot of and start over.
agreed, just scrape back and mist coat. No need to overcomplicate - keep it simple!
The ceiling was very powdery when I tested ,the alkauli sealer ,will help stick everything down.