Leaky ceilings and basements can sometimes lead to water marks and stains on your painted walls and ceilings. These paint stains look bad and can stay around long after water problems are fixed. Learning to remove or cover water marks and stains will allow you to renew your walls and ceilings. It is always easier and less expensive to remove the marks when possible. If that doesn't work, you may need to resort to covering up the stain.
Create a cleaning mixture to remove the water stains and marks from the painted ceilings and walls. Fill a large bucket with 5 litres (1 gallon) of warm water. Mix 1 cup white distilled vinegar, 1 cup baking soda, and ½ cup ammonia into the warm water.
Clean the painted walls and ceiling with the mixture and a sponge or damp towel. This initial cleaning should help you determine whether the water stain is going to be removed. Once the wall is clean, wipe it down with a dry towel.
Cover tough water marks in the paint with shellac and a paintbrush. You cannot simply paint over the marks with latex paint because the stain will seep through the paint. Instead, cover the mark with shellac and let dry per manufacturer directions.
Touch up the latex paint with leftover or matched paint and a paintbrush. Let the paint dry per manufacturer directions.