Said It Here

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 people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Checking bathroom plumbing and attic or ceiling cavities
  2. 2
    Using a moisture meter
  3. 3
    Checking the attic, roof, and siding for any intrusion
  4. 4
    Checking whether the carpet under the bed frame is dry with hands
  5. 5
    Using a non contact moisture meter to confirm moisture levels
  6. 6
    Calling the installation or service company to inspect and seal ducts
  7. 7
    Hunting for air leaks using toilet paper and sealing seams with foil tape
  8. 8
    Treating affected areas with bleach or D7

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/HomeImprovement1 person · September 2026

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 ↗

AKid4971 · r/HomeImprovement · 2 upvotes
r/HomeMaintenance1 person · September 2026

Thanks, figured it was but also figured the spot would be somewhat soft or cold/wet which it isn’t.source ↗

Grandimal · r/HomeMaintenance · 1 upvotes

These spots on the drywall have gotten a tiny bit larger and darker over the last many months.source ↗

I’m all outta guesses…source ↗

Grandimal · r/HomeMaintenance
r/Plumbing1 person · September 2026

Theyre both very faint and completely dry to the touch. Should i be worried about an active leak?source ↗

Vietname · r/Plumbing · 1 upvotes
r/hvacadvice1 person · September 2026

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 issource ↗

Rare_Square_7985 · r/hvacadvice · 1 upvotes

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 ↗

Rare_Square_7985 · r/hvacadvice · 1 upvotes

Where this came up

People with this problem also raised