Hi, I was looking for some advice in regards to repainting a ceiling that has been stained due to a radiator leak (attached image). Ideally I would like to just paint the affected area as the rest of the ceiling is in really good condition but not sure what the best thing to do is. I have read that I should use an oil based undercoat and then paint on top, but being a new build property by Taylor Wimpey I was told that they used builders paint and not sure where I can buy this from and the builders have been no help at all.
Any advice would be really appreciated.
