Roof or AC
On a top-floor ceiling, rain-related drips point to the roof or a flashing. Dry-weather drips on hot days point to the attic air handler's drain.
Read more: roof leaks · AC leaks
Water coming out of a light fixture, a recessed can, a ceiling fan or a bathroom exhaust fan needs two things done in the right order: make it electrically safe, then find out where the water is really coming from.
If you smell burning, see sparks or the breaker keeps tripping, leave the power off and call an electrician or 911 for an emergency. Don't reset a breaker on a wet circuit.
For a fuller walkthrough of the first hour, see what to do when water drips from a light fixture.
What's above the fixture tells you where to look.
On a top-floor ceiling, rain-related drips point to the roof or a flashing. Dry-weather drips on hot days point to the attic air handler's drain.
Read more: roof leaks · AC leaks
Downstairs lights under an upstairs bathroom are the classic case in Diamond Bar's two-story tract homes.
Read more: bathroom leaks
A pipe running over the room can weep onto the top of the drywall for weeks before it drips through a can light.
Read more: pipe leaks
This is one of the most common "leaks", and it's not a leak at all. A shower fills the bathroom with warm, saturated air. The fan pushes it through a duct across the attic. In fall and winter the attic is much cooler than the bathroom, so moisture condenses inside the duct and runs back down to the fan.
The fix is in the attic: an insulated duct, run as short and as straight as possible, sloped so condensation drains outward, ending at a roof or wall cap with a working damper. Then any stained or soft drywall around the fan is repaired.
Moisture readings around the fixture and up toward the source.
Plumbing, AC drain, roof or duct repair coordinated with the right trade.
Wet drywall and insulation out around the box; cavity dried and checked.
Fixture, box and wiring inspected or replaced by an electrician.
New drywall, texture matched, ceiling repainted, fixture reinstalled.
Common questions when water comes out of a fixture.
A ceiling contractor handles the ceiling: finding the water source, drying the cavity and rebuilding the drywall around the fixture. Until a fixture that got wet has been checked, keep the breaker off; if it scorched, buzzed or tripped, have an electrician inspect or replace it before the power goes back on.
Because the fixture is a hole. Water that's been spreading across the top of the drywall finds the opening around the box or the recessed can and drains through it. The fixture is rarely the source. It's just the lowest, easiest way out.
Not until the fixture, box and wiring have been checked. Water can leave corrosion and residue inside a fixture or junction box that causes problems later. A wet fixture is usually replaced rather than reused, and an electrician should confirm the circuit is safe.
Usually it's condensation, not a leak. Warm, wet air from the shower travels up the fan duct into a cooler attic, condenses inside the duct, and runs back down to the fan grille. It's worst on cool mornings. The fix is an insulated duct with a short, sloped run to a proper exterior vent, plus a working backdraft damper.
Same physics as a light: water above the ceiling finds the fan's electrical box. On a top-floor room it can be the roof or the AC. Under a bathroom it's usually plumbing. Turn the fan and its breaker off and leave the fixture alone until the source is found.
Get connected with a local contractor who can find and stop the water source, dry the cavity and repair the ceiling. The fixture, box and wiring are checked or replaced by an electrician, scheduled while the ceiling is open so nothing has to be cut twice.