How can I cover and paint over a water-stained but otherwise undamaged ceiling?
After you have corrected the cause of the water staining, use a primer sealer designed for stain blocking, such as PrepRite ProBlock Primer/Sealers. They are available in both alkyd and latex-based versions. While both work to block this type of stain, the alkyd stain blocker will usually seal water stains better because it doesn’t contain water that could re-wet the stain. You may still see the stain through the stain blocker, but they are designed to “lock-in” the stain to prevent it from bleeding through into the topcoat.
