Stains. A bubble forming under paint. Water drip, drip, dripping. You’ve got a leaky ceiling – but what does it mean? Sometimes zeroing in on the source of a ceiling leak can be harder than making the repair itself. Identifying the source may require a bit of detective work (or the help of a seasoned pro), but here are a few of the most common reasons your ceiling may be leaking.

1. A leaky roof
It’s possible for water to get under roof flashing, between shingles or broken siding, through failing gaskets and other spaces like chimneys, vents or skylights. If your leak presents itself in stormy weather and then dries up when the weather clears, there’s a good chance your leak is on the roof. Pinpointing the exact entry point may require some serious sleuthing (and possibly some professional assistance), since water can be diverted through attic insulation, rafters, joists, pipes or ductwork.

2. Clogged gutters
Gutters collect leaves, dirt, twigs and other debris that can prevent downspouts from doing their job. Water may buildup in a clogged gutter and pool, resulting in any number of issues (including that leaky ceiling).

3. Condensation
Noticing drip marks or droplets on your ceiling? Cooking, showering, drying clothes (and even breathing) are all activities that raise the humidity level in your home. Inadequate or poor ventilation or insulation can trap moisture in a room, eventually leading to water damage.

4. A leaky pipe
Got an upstairs bathroom? Dripping water or wet spots in a room under a bathroom should raise serious red flags. From clogged drainpipes (look for damp spots that dry out and then return) to damaged water supply lines (these tend to steadily drip), plumbing leaks can quickly permeate surrounding surfaces.

5. Splash leaks
When water consistently pools outside an upstairs shower or bathtub enclosure, you can get damage from a splash leak. Over time, water that drips and splashes can permeate the subfloor, loosening caulking, tiles, underlayment and flooring, and causing rot (not to mention water stains on your ceiling).

6. Old caulking or grout
Caulk, typically used where bathroom fixtures meet the wall or where the wall or tile meets the tub, and grout, used between tiles, are both susceptible to age, poor installation, and general wear and tear. Once caulking or grout cracks, moisture can leak through to plaster, drywall or subfloor, penetrating and damaging surrounding surfaces.

7. A bad wax seal
If you have water seeping out and collecting around the base of your toilet, you may be dealing with a failed wax seal. Wax gaskets, when working correctly, create a watertight seal between the toilet and the toilet drain. When a wax gasket fails, leaking toilet water can seep through the floor, penetrating the subfloor and damaging the ceiling below.


8. Blocked drain in HVAC unit
Central air conditioning units can leak. Sometimes there’s a problem with a drain pan or a condensate line, other times it may be a clogged air filter. Blocked condensate drainpipes tend to be the most common cause of these leaks, with water backing up at the clog and overflowing the pan, leaking into surrounding areas.

Leaks are unpleasant business, but delaying maintenance can lead to dangerous conditions and costly repairs. Reinforce your home’s safeguards with homeowner’s insurance you can count on.

Safe and smart | Home safety


about Rebecca

Rebecca is a freelance copywriter and editor living in the SF Bay Area with her husband and two kids. She enjoys productively channeling her anxiety into safety-minded articles for home and garden, running with her robot trainer, and advocating on behalf of the Oxford comma.