Tracing a Water Leak Behind the Wall and in the Ceiling

Inspect the walls and ceiling for circular wet spots, peeling paint or bubbling drywall. Remember that not all leaks in the wall and ceiling are located where the wet spot is appearing. Water may travel down the line.

Find the dark spot of the water damage. Water likes to travel down, meaning lighter spots are likely the start of the water leak.

Leave the water in upstairs fixtures off for a few days. If the leak stops, there is likely an issue with one of the drain lines. Turn on one fixture at a time and see from which drain line the leak appears. A supply leak is a probable cause if the leak continues even with the faucets turned off. Shut off the water supply lines if the leak continues to see if this solves the problem.

Turn the shutoff valves in the house off one at a time to isolate where in the house the leak is coming from. Shut off the upstairs water lines and open the faucets. Allow several hours to pass to see if this stops the leak. Continue working your way down the house, toward the water main lines, to trace the leak location.