Water marks on your ceiling are not only unattractive, they are also harbingers of bigger trouble looming on the horizon. Any number of things can cause water stains on your ceiling, from a leaky roof to leaky plumbing. Leaky plumbing can either be a leak in a water pipe, or it may be a leak in a shower stall, around a tub or sink or a toilet. Sometimes you have to simply caulk a crack or replace a fixture, and still other times you may have to find the pipe that is leaking. If you notice water marks on your ceiling, before you even think about fixing the water marks make sure that you know what caused them and correct that problem. Once the repair has been made, then you can turn your attention to the actual stain on your ceiling.
Assess the Situation
After you find the water mark on your ceiling, you are going to want to see how extensive the water damage is. You will also need to determine if the ceiling materials are damaged as well. If you see that the drywall has been softened by the presence of moisture, you may want to cut out the damaged piece of ceiling and patch it. If you have damage to insulation you will have to remove and replace that as well. If the drywall gets too soft and crumbly, generally you will have trouble getting paint to stick to it. So before you try to hide the water stain, determine if you have a surface that will stand up to paint.
To fix a light water stain, you can first try washing the area with bleach. Sometimes this will save you from having to repaint the area. Pour undiluted bleach into a container and use a rag to dab bleach onto the affected area. Within a few minutes, the bleach should fade the stain. You may have to reapply the bleach to the area several times. Once the area has dried completely you can touch up with paint or chalk if you have a white ceiling. Although you may find that you do not need to touch up the bleached area at all.
Most of the time when you have a water stain on your ceiling you will probably simply want to seal the area and then paint over it. Water stains can be stubborn, and they frequently bleed through your new paint job if you do not properly seal them. You will want to use a shellac based primer or stain sealer on the area before you repaint it. Look for a primer designed to seal water stains. Make sure that you have good ventilation before you start painting, and cover the entire area with the stain sealing primer. Then make sure that primer is completely dry before repainting the affected area. If you properly seal the area, you should not have any problems with bleed-through after painting.