DIY Doctor UK DIY Forums

We have a large damp patch on our pale painted plastered wall which was caused by a radiator leaking from the room above.This happened nearly two years ago so has dried out but left a stain from the radiator water.We have painted over it many times with emulsion,first seven coats of white and then the pale wall coloured paint but the stain still shows through. This is above the window so not a plasterboard wall.Would sanding it out be the only answer.

Many thanks for any help

All you are doing is rewetting the stain every time you paint and its leeching through. Go over it with a specialist stain block or oil based undercoat first then your ordinary paint.

Cheers