Water that reaches drywall carries dust and minerals with it. When it dries, it leaves a brown or yellow ring, often darker at the edges. The stain shows you that water got in, but the source can be several feet away, because water travels along rafters, decking and pipes before it drips.
Common Sources in Albuquerque Homes
- Roof leaks. Failed flashing, cracked pipe boots, worn shingles or a clogged flat-roof drain.
- Swamp coolers. Overflowing pans, cracked stands and worn flashing around the cooler curb are a very common cause here. See our swamp cooler roof leak guide.
- Refrigerated AC. A clogged condensate line or an overflowing drain pan in the attic can drip through the ceiling in summer, even when it hasn't rained.
- Plumbing. Supply or drain lines in the attic or an upstairs bathroom.
- Condensation. Warm, moist air meeting a cold roof deck in winter, often from bath fans that vent into the attic instead of outside.
- Ice at the roof edge. In the foothills and East Mountains, snow that melts and refreezes can back water under shingles. See snow and ice dams.
How to Narrow Down the Cause
| What you notice | Likely source |
|---|---|
| Stain grows or appears after rain | Roof, flashing or flat-roof drainage |
| Stain appears only in wind-driven monsoon storms | Flashing at walls, chimneys or parapets |
| Stain appears in summer with no rain | Swamp cooler or AC condensate |
| Stain is below a bathroom or near a water heater | Plumbing |
| Stain appears in winter, often with frost in the attic | Condensation or poor ventilation |
| Stain near an exterior wall on a stucco home | Roof-to-wall flashing or cracked stucco |
What to Do Right Away
- Take photos of the stain with the date. Photos over a few days show whether it's growing.
- Check the attic if you can do it safely. Look for wet insulation, dark or stained decking, and drips. Trace wet wood uphill toward its highest point.
- Protect the area below with a bucket or tarp. If the ceiling sags or bulges, keep people away from it, because wet drywall can give way.
- Turn off the swamp cooler if the stain is near it and see if the problem stops.
- Don't just paint over it. Stain-blocking primer hides the mark but not the leak, and the next storm will bring it back.
Hidden damage: by the time a stain shows on the ceiling, insulation and decking above it have usually been wet for a while. Wet insulation loses much of its value and can hold moisture against the wood, so the source should be fixed and the attic dried out, not just the drywall patched.
When It's the Roof
If the evidence points to the roof, the fix is to find where water actually enters, which is often uphill from the stain. Our roof leak repair process starts with tracing that path and documenting it with photos. Most roof leaks come from flashing rather than the shingles themselves. On flat roofs, check our guide to flat roof drainage.
If the leak started after a storm, it may be storm damage your insurance covers. See what to do after storm damage before calling your insurer.