Bathrooms may flood, especially since they have multiple plumbing fixtures in them that can be the source of water spilling out onto the floor. If you cannot prevent a flood in your bathroom, you need to understand the potential damage to your house, including the ceiling below the bathroom.
Stopping the Flooding
When you bathroom floor floods, the first thing you need to worry about is stopping the source of the flooding. If you concentrate on sopping up the water on the floor, the problem will just continue to grow. Close the overflowing plumbing fixture's water supply valves, if you know where they are located, or just close the main water valve for the house. With the water supply turned off, you need to then concentrate on getting as much of the water off the floor as quickly as possible before it finds a way into the subfloor.
Ceiling Damage and Repair
Drywall may become wet to a point and not need to be replaced. You may notice a water stain on the ceiling after the drywall has dried out, but you can paint over the stain to restore the look of the ceiling. If the drywall becomes wet to the point that it starts to fall down or crack, or if mold starts to grow in it, you need to remove the damaged drywall and patch the hole in the ceiling. If the hole is large enough and the patch does not stay in place, place a backing board on the other side of the ceiling so the patch has a surface to cling to.
Sub Floor Damage
Even if the ceiling is not badly damaged, water surely soaked a portion of the sub floor if the ceiling was wet. You may not see the damage in the sub floor, but it can still pose a serious problem. If the floor joists warp and weaken from the water or if mold grows from the water exposure, the floor may fail and fall into the room below. Repairing damage to the bathroom's sub floor involves tearing up the flooring and is an extensive process. If you decide to make the repairs yourself, wear a protective face mask and gloves since you may encounter mold growth.
Preventing Future Floods
The best way to deal with flooding is to take steps to stop future flooding in your bathroom. Some homeowners do not think about the overflow drain in their sinks or bathtub until the sink or bathtub is almost overflowing. These drains may clog up with debris over time and must be cleared out. You can pour bleach down the overflow drains periodically to break up any clogs inside of them. If you are dealing with a clogged toilet, you should shut off the water supply valve so you cannot flush the toilet more than once before you eliminate the clog.