How to Troubleshoot and Repair a Leaking Ceiling

Ceiling leaks can signal the presence of a larger problem lurking in the attic, roof, or upper floors. If your ceiling is leaking, there are two likely culprits: an issue with your plumbing (like a damaged pipe) or an issue with your roof (like overflowing gutters). Identifying the ceiling leak, tracing it to its origin, and stopping it must all be done before repairing the ceiling.

Signs of a Leaking Ceiling

A ceiling leak can be as obvious as water dripping from the ceiling onto the floor, or it can manifest itself in ways that are more difficult to detect: musty smells, ceiling fixtures full of water, or infestations of insects. Most ceiling leaks are persistent, not one-off or isolated problems. The leak does pass through the ceiling, but it can also continue and drip down walls.

Bubbled Paint

Bubbled ceiling paint is often a sign of a ceiling leak. Interior latex paint is sturdy enough to hold in water, much like a balloon. So, the water passes through the ceiling drywall or plaster and is held back by the paint layer.

Dark or Rancid Water

The leaking water is often dark-colored and it will stain white or light ceilings or walls. It may smell mildewy or even rancid. Or, the water might be clear and odor-free.

Events Causing Leaks

A leaking ceiling can often appear after it rains or snows or with activities in the home, such as flushing a toilet or taking a shower. Ceiling patches may even indicate previous ceiling leaks.

Safety Considerations

Investigating and stopping ceiling leaks can place you in the way of any number of household dangers: lead-based paint in the ceiling; asbestos in the ceiling insulation or on pipe wrap; or black mold behind drywall or in insulation. Climbing ladders into attics or onto roofs may cause you to fall. Falls are a leading cause of household injuries or death.

How to Check for Internal Ceiling Leaks

1. Mark Pooled Water and Rule Out Potential Causes

   Start at the water’s end-point. If the water is pooling on the ground, mark the area with a bucket, painter's tape, or chalk. Eliminate condensation as the cause of the ceiling leak. If condensation is the source, add an exhaust fan or run a dehumidifier.

2. Make Note of Water Leak Area

   Follow the pool of water upward. The drip area on the ceiling is usually obvious and remains even after the drip has dried up. Water travels downward, seeking the path of least resistance, though sometimes with a circuitous route. If the drip area on the ceiling is widespread, mark its outline with a pencil. Test areas that are not visibly obvious with the moisture detector.

3. Look for Collection Points

   Light fixtures sometimes act as containers for ceiling leaks. The leak may not necessarily be directly above the fixture. Instead, the fixture is the lowest point on the ceiling, so it collects water. The tops of kitchen wall cabinets, too, act as collectors for water leaks.
   

4. Check Areas Above the Leak

   If the area above the leak is an attic, access the attic and locate the area of the leak. Roll up fiberglass insulation batts. For loose-fill cellulose insulation, scoop it up with a dustpan and set it aside.

   If the area above the leak is a roof, see if the underside of the roof is wet. Underside leaks of this type often start high and move downward. So, if the roof is leaking, the leak may be located at the beginning point of the leak's path.

   If the area above the ceiling leak is a habitable floor instead of an attic, try to locate the exact area above the ceiling leak by measuring inward to the leak from the walls. If a bathroom is directly above the leak—specifically the bathroom's toilet, shower, or bathtub—there is a good chance that the leak is coming from any of those. In some cases, water supply lines or drain lines behind walls or under floors may be leaking.

Examine Home for External Ceiling Leaks

1. Check Gutters

   Rest the extension ladder against the house to look at the gutters. Gutters full of leaves or debris can overflow back into the house’s attic. Gutters that do not maintain a slope of at least a 1/4-inch vertical drop per 10 horizontal feet can collect water and send it back into the attic.

2. Investigate Roof, Roof Ridge, and Flashing

   From the top of the ladder, look at the roof. Raised, damaged, or missing shingles may be leak points. Damaged shingles near the edge of the roof may indicate water leakage from ice dams. Walk on the roof and further examine the shingles, along with the roof ridge. Look at the metal step flashing alongside the chimney for signs of water entry points. Check all pipes and vents that extend from the roof.