Watermark on ceiling

[Diamonds16]

Hello,

I moved into my house about 11 months ago, there was a yellowish patch on the ceiling around the chimney breast in the bedroom which clearly had a leak at somepoint, looks like this was repaired (as it was not wet) so I painted over it (white paint) about 9 months ago but the stain has come back again, any suggestions how I get rid of it for good??

 

[TheDec]

When you say white paint I take it you mean emulsion, providing the cause of the water mark has been cured, to stop it's return first use either an alkali resisting primer or an oil based undercoat before you emulsion.

Dec

 

[opps]

or if you want some thing that you can overcioat with emuslion in minutes then use a shellac based product such as Zinsser BIN

 

[Diamonds16]

sorry yes I mean emulsion, thanks for the advice I'll try that, be nice not to see the stain anymore any ideas why its come back? thought a couple of coats would do the trick

 

[TheDec]

It is the water content of the emulsion that will re-activate the staining and will in time show itself again.

Therefore it needs to be blocked by applying the correct product, then it's goodbye stain.

Dec.

 

[Diamonds16]

Thats really interesting, Thank you