Said It Here

Unexplained holes or damage inside the house

Unexplained holes or damage can appear suddenly in hidden areas like closets or crawlspaces, leaving homeowners unsure whether to seal them up or investigate further. This uncertainty triggers immediate panic about structural integrity or hidden pests, preventing people from feeling safe or knowing the correct next step to take.

Overview
People affected17 accounts across 6 forums
Workarounds found29 items attempted
Community agreement4,730 total upvotes

What the numbers show

Counted from the threads quoted below. How we count

  • Most of it landed at once — the busiest month was September 2026, with 11 people.
  • This comes up 15.9× 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.

29 items+ Contribute

Found another way around this?

Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.

  1. 1
    filling the hole with water using a hose to check for voids
    Did this help you?
  2. 2
    sealing the hole, packing the dirt, and regrading away from the house
    Did this help you?
  3. 3
    Guessing the cause from online forum responses
    Did this help you?
  4. 4
    Checking for active dust near holes
    Did this help you?
  5. 5
    inspecting for dust or evidence of termites
    Did this help you?
  6. 6
    considering whether previous occupants hung frames or items on the walls
    Did this help you?
  7. 7
    taping the holes back up with foil duct tape
    Did this help you?
  8. 8
    calling a plumber or handyman to inspect
    Did this help you?
  9. 9
    posting pictures online to ask communities for advice
    Did this help you?
  10. 10
    waiting to see if the issue worsens over time
    Did this help you?
  11. 11
    Having an HVAC technician look at the ductwork to insulate or repair as needed
    Did this help you?
  12. 12
    Spraying the underside for mold remediation
    Did this help you?
  13. 13
    Negotiating seller concessions based on the inspection findings
    Did this help you?
  14. 14
    asking online forums to identify strange equipment marks
    Did this help you?
  15. 15
    reaching out to the landlord and sending photos of the damage
    Did this help you?
  16. 16
    calling exterminators or specialists to inspect the damage before continuing the project
    Did this help you?
  17. 17
    stopping the renovation project to investigate and address the issue
    Did this help you?
  18. 18
    Consulting online forums and communities for reassurance from other homeowners
    Did this help you?
  19. 19
    Spackling and painting over hairline cracks as a quick fix
    Did this help you?
  20. 20
    Adjusting appliance feet to compensate for uneven floors
    Did this help you?
  21. 21
    Shining a light into the hole or poking around with a screwdriver to check depth and hollowness
    Did this help you?
  22. 22
    Filling shallow holes with hydraulic cement or concrete patch
    Did this help you?
  23. 23
    Consulting an expert or home inspector to evaluate the issue
    Did this help you?
  24. 24
    trying to scrape it off
    Did this help you?
  25. 25
    calling the landlord to report a potential leak
    Did this help you?
  26. 26
    Replacing only the damaged section of the subfloor instead of doing a full tear-out
    Did this help you?
  27. 27
    Using specialized antimicrobial cleaners or white vinegar instead of bleach to treat porous surfaces
    Did this help you?
  28. 28
    Avoiding homeowners insurance claims for maintenance issues to prevent premium hikes
    Did this help you?
  29. 29
    Buying new power tools mid-project to speed up the unexpected extra work
    Did this help you?
Tried another approach not listed above?+ Share your workaround ↑

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/HomeMaintenance9 people · November 2025 – October 2026

“We'd kept this closet closed all winter, and opened it to find this.”source ↗

“What the heck am I looking at here?”source ↗

mecklejay · r/HomeMaintenance · 3,816 upvotes

“Noticed that this beam under where our toilet is, is white with some greenish flakey stuff on it? Is this mold? Also don’t even know where to get started taking care of it if it is mold….”source ↗

Th3priceisright · r/HomeMaintenance · 711 upvotes

“What are these holes for throughout my dryer vent duct?”source ↗

“Had an inspection and they are saying this is damage and I need to replace the whole vent line which has never been an issue in the past 8 years I’ve had my home and every year I get a cleaning and inspection done.”source ↗

pvo129 · r/HomeMaintenance · 10 upvotes

“Saw this in my cupboard, also on some other wood around the house. Canada btw”source ↗

YugiohUniverse · r/HomeMaintenance · 2 upvotes

“Does anyone know what this could be? A strange plastic/honeycomb/webbed looking protrusion on an interior wall, 1930s apartment complex in NYC. I'm assuming somehow related to water damage since I have water leaks through the upper window frames but I honestly have no idea.”source ↗

Solid_Confusion_9192 · r/HomeMaintenance · 2 upvotes

“I'm worried the couch has likely been there a long time, so it could be worse than what it's presenting.”source ↗

mellikoala · r/HomeMaintenance · 1 upvotes

“That's my worry...clearly they've had their couch there for a long time. I am concerned the fix would be more than just drying out the area of subflooring that is currently wet. Trying to decide what's worth negotiating on some seller concessions.”source ↗

mellikoala · r/HomeMaintenance · 1 upvotes

“The wall beside the stairs has a bit of a ridge to it, but it is not at floor level.”source ↗

“Is it something humidity related? And is it concerning?”source ↗

SubstantialTime8168 · r/HomeMaintenance · 1 upvotes

“I just bought the house 2 weeks ago and the inspector didn’t point it out and I just noticed it.”source ↗

AskAdditional5045 · r/HomeMaintenance · 1 upvotes

“Could be moisture behind the wall. I had something similar in a bathroom wall and we tracked to a roof leak.”source ↗

Franklin_Murphy · r/HomeMaintenance · 1 upvotes
r/homeowners4 people · September 2026 – November 2026

“Started with a simple toilet replacement. Then I found out they put new flooring was on old flooring. And the old flooring was stained from an old water leak. Then the underlayment was waterlogged and now the sub floor is molded... Now I have to consider a full bathroom remodel depending on how far some of the mold goes.”source ↗

“I have one goddamn day off a week and this is how I spend it.”source ↗

“I have all the new wood and a flipping moisture barrier to go with new flooring since the last guy didn't know jack about shit.”source ↗

snowball283 · r/homeowners · 333 upvotes

“Hole I found while digging through the rock beds. Some very loose/soft dirt there too.”source ↗

“Seal off the hole and forget it exists? Or keep panicking?”source ↗

Spiritual_Ask_8979 · r/homeowners · 46 upvotes

“My friend I just went through this exactly. Sorry it’s happened to you, but this is just how it goes sometimes as a homeowner.”source ↗

pnsmcgraw · r/homeowners · 3 upvotes

“I already know its just a section for the sub floor thankfully. Each part is easy but all together its a chore for sure. Its just more annoying realizing a circular saw would make this infinitely easier.”source ↗

snowball283 · r/homeowners · 2 upvotes

“We moved into an older home a couple of months ago and it quickly became apparent that the previous owner had painted over cracks in the walls and ceiling.”source ↗

“Also, we discovered that the kitchen floor is slightly sloped. The inspection report was clear and the slope wasn't mentioned, but then some doorframe cracks and this ceiling crack (pictured) became visible.”source ↗

“If we had noticed the sloped floor, we wouldn't have bought this house.”source ↗

“Is this ceiling crack in the realm of normal, or is this something we should get an engineer to investigate?”source ↗

“And do we have any recourse with our home inspector?”source ↗

allsorts_ · r/homeowners
r/HomeImprovement1 person · September 2026

“was just trying to run a new outlet, cut into the drywall, and found what looked like sawdust piled up along the bottom of the stud bay.”source ↗

“turned out there'd been a slow leak behind that wall for who knows how long. glad i found it mid- remodel instead of after closing everything back up”source ↗

Obvious_Doughnut_966 · r/HomeImprovement · 94 upvotes
r/hvacadvice1 person · September 2026

“I can't tell if it's mold or something caught fire, should I be worried?”source ↗

Regular-Bother-832 · r/hvacadvice · 2 upvotes

“Yes and the fact that there's a giant hole in the one picture”source ↗

Regular-Bother-832 · r/hvacadvice
r/Pestcontrol1 person · September 2026

“I’m noticing these small pinholes - most all of them are in a uniform horizontal line.”source ↗

“curious if these look like a particular pest? Or if they’re nail pop related?”source ↗

Successful-Fly5549 · r/Pestcontrol · 1 upvotes
r/Plumbing1 person · September 2026

“the patch fell off to reveal this. It looks like an indentation/crack, but I can’t tell if it’s worth reaching out over?”source ↗

“Candidly, this would be the second bathroom related issue that he’s had the send a plumber, so I’m a little weary”source ↗

ComprehensiveTour510 · r/Plumbing

Where this came up

People with this problem also raised