Do I need to replace my plaster ceiling plasterboard that got soaked from an upstairs bathroom leak? ?
If you are absolutely certain the leak has been fixed and there is no more water dripping... 1. Place a fan facing toward the ceiling for about a week or as long as it takes to make sure the ceiling is completely dry. 2. Paint the stained area with Killz. (Not sure of the spelling but it's a water stain retardant) Let it dry overnight, regardless of what the directions say telling you it's dry in less than two hours. 3. Paint the surface again with Killz 24 hours later. 4. Wait 24 hours to see if the stain is visible. If it is, paint another coat of Killz. 5. If the stain is undetectable, wait 48 hours and paint the ceiling with with the color of your choice. A second coat of paint may be required.