Why is my dry ceiling stain getting bigger?
Ceiling spots can slowly expand and darken over months even when the drywall feels completely dry and firm to the touch. This makes it nearly impossible to identify the source of the leak or figure out what action to take next without guessing.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 19.2× more often in r/HomeMaintenance than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Checking bathroom plumbing and attic or ceiling cavitiesDid this help you?
- 2Using a moisture meterDid this help you?
- 3Checking the attic, roof, and siding for any intrusionDid this help you?
- 4Checking whether the carpet under the bed frame is dry with handsDid this help you?
- 5Using a non contact moisture meter to confirm moisture levelsDid this help you?
- 6Calling the installation or service company to inspect and seal ductsDid this help you?
- 7Hunting for air leaks using toilet paper and sealing seams with foil tapeDid this help you?
- 8Treating affected areas with bleach or D7Did this help you?
- 9poking and prodding the ceiling to check if it feels spongyDid this help you?
- 10checking the attic for signs of moistureDid this help you?
- 11wiping the spot awayDid this help you?
- 12theorizing about inadequate ventilation near the kitchenDid this help you?
- 13Checking what is located above the ceilingDid this help you?
- 14Monitoring for recent rain or water activityDid this help you?
- 15checking with a moisture meterDid this help you?
- 16removing a can light to look inside the ceiling cavityDid this help you?
- 17installing hanging drop ceilings over cracked drywallDid this help you?
- 18Inspecting the attic floor and looking up at the roof or vents to find the exact spotDid this help you?
- 19Consulting online product lists or communities for maintenance adviceDid this help you?
- 20putting a towel underneath the dripDid this help you?
- 21checking the pan and condensation drains for clogsDid this help you?
- 22calling an HVAC company to inspect the unitDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I’m concerned this is a sign of water damage and I have no idea where to start in trying to figure this out.”source ↗
“What does it feel like if you touch it, pick up a cheap moisture meeter and test that area.”source ↗
“Had these in my house growing up and it was a leaky vent in the attic. Try to pinpoint that exact spot in the floor of the attic and look up”source ↗
“Thanks, figured it was but also figured the spot would be somewhat soft or cold/wet which it isn’t.”source ↗
“I have these spots on my ceiling”source ↗
“-i have a three year old roof. I already poked and prodded the ceiling. It doesn't feel spongy.”source ↗
“-I've previously checked my attic. No sign of moisture. There's no plumbing above this spot.”source ↗
“I noticed them in February. I've been here since 2020. One kid but way too young to do any damage”source ↗
“That's a leak”source ↗
“Hello these just showed up today on the second floor ceiling . Can someone pls advise who to call?”source ↗
“The unit is dripping from under the pan. I can’t see well and the unit is behind lots of pipes and ducts. I put a towel underneath using a long broomstick cuz it’s too far to reach . Is this urgent and need to replace whole unit or restoration? I’m freaking out !”source ↗
“We just had our ceiling painted and noticed this spot two days later.”source ↗
“We just moved into our home recently and are not sure if this was here before the painting was done.”source ↗
“Does this look like a small water spot/potential active leak or something different?”source ↗
“Something just happened to our ceiling in the past few days and I can’t figure out what’s causing this.”source ↗
“I just saw these leak stains a few days ago on the ceiling of my living room.”source ↗
“Can anyone please tell me what these are and what I should do?”source ↗
“We had a new air handler installed mid July. I’m just now getting around to putting stuff back into the utility closet and noticed this at the top of our ceiling.”source ↗
“Can someone please calm me down and tell me this isn’t as big of a problem as I think it is”source ↗
“We have a call into the company that installed it in July. Just wondering how bad of a situation this is. I have no knowledge about this at all other then mold means bad 🤦🏻♀️”source ↗
“Theyre both very faint and completely dry to the touch. Should i be worried about an active leak?”source ↗
Where this came up
People with this problem also raised
- 13Why is there a weird drop in my ceiling?
- 3What are these stains and damage on my attic roof sheathing?
- 6How to get an old coffee stain off the ceiling
- 4Why is this wall discolored if it is not wet?
- 5White cottony growth on basement wall mold or mineral deposits?
- 26How to clean mold on furniture after rain gets inside