What is the best way to repair 20 cms diameter water damage to a plasterboard ceiling?
If it is just the stain you are worried about you can use a good stain blocker primer and then repaint. I personally like Zinsser.
I HAVE USED WHITE SHOE POLISH AND IT DID VERY WELL.
tear it out and put in new...that's all you can do otherwise the damage is still there, even if you can't see the water spot(s)
