What is this random dripping exterior pipe on my house?
An unidentified exterior pipe dripping against the foundation wall can indicate a plumbing leak or groundwater discharge, leaving homeowners unable to determine if the issue requires urgent repair or will cause structural damage. This uncertainty often leads to moisture spreading to interior areas like the vanity, making it difficult to assess the actual source or severity of the problem.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 10.1× more often in r/Plumbing 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.
- 1Asking online forums for identification2 people mentionedDid this help you?
- 2Pressure washing the area and adding an extension hose to direct water further from the houseDid this help you?
- 3Checking p-traps and supply line connectionsDid this help you?
- 4cutting into drywall to inspect for moistureDid this help you?
- 5Removing the mystery pipe and installing a brass plug or hose bib insteadDid this help you?
- 6checking the roof to see if a pipe cap blew offDid this help you?
- 7Snaking out leavesDid this help you?
- 8Pouring water down the pipe to see if it drains or fillsDid this help you?
- 9Putting a vented cap or a removable cap on itDid this help you?
- 10Sniffing or shining a flashlight insideDid this help you?
- 11Trying to clean out debris with a snakeDid this help you?
- 12Flushing toilets to listen or smell for sewer gasesDid this help you?
- 13Shining a light down the pipe to check for a rod or depthDid this help you?
- 14Checking potential sources like hot water heaters or air conditioning unitsDid this help you?
- 15Shutting off the main water valve to drop water pressure throughout the houseDid this help you?
- 16Calling a plumber for an on-site inspectionDid this help you?
- 17poking around during dry weather to see if there is a cap further downDid this help you?
- 18checking if they are property boundary markers or septic ventsDid this help you?
- 19Trying to diagnose the leak source from photos onlineDid this help you?
- 20Considering whether to attempt a DIY fix or call a plumberDid this help you?
- 21Asking online communities for advice before modifying plumbingDid this help you?
- 22Leaving the pipe uncapped while unsure of its functionDid this help you?
- 23Leaving the object alone and planting a bush over itDid this help you?
- 24Asking online home maintenance forums for identificationDid this help you?
- 25digging out more dirt around the pipe to see where the cavity goesDid this help you?
- 26asking plumbing forums for identification based on context clues like gutters and city sewer statusDid this help you?
- 27Asking on plumbing forums for help identifying the pipesDid this help you?
- 28Leaving the pipes alone if there are no current issuesDid this help you?
- 29Posting photos and descriptions of the material to online forums for identificationDid this help you?
- 30Digging around the object to see where it leadsDid this help you?
- 31Covering it up with concrete and ignoring itDid 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.
“Just bought a house and thisbopen pipe is on the front lawn. What is it and should I clean the leaves out with a snake and cap it?”source ↗
“Bought a house and this open pipe is in the front yard. Leaves and debris are getting into it so I'm wondering if i should clean it out with a snake and cap it off.”source ↗
“I was digging a hole to plant a tree and suddenly the ground sunk into this hole which revealed an abandoned pipe that’s not capped. Can someone tell me what this is?”source ↗
“I’m really confused on what this is for as I’ve never seen anything like it.”source ↗
“Hey all, I live in a terraced house, just wondering why there are 3 pipes here.”source ↗
“Exploring my garage and next to water heater was this random pole sticking out of the dirt.”source ↗
“Wondering if I should just cover it in concrete or worth digging a little bit more.”source ↗
“What is this long rusty extension on our outdoor tap?”source ↗
“Can’t figure out what this long rusty extension is for though.”source ↗
“help me identify what this is sticking out of the ground next to my house in SW Florida?”source ↗
“I don’t have any idea what this pipe is and why it’s constantly dripping water, but I’ve had this puddle for a while now. Can anyone explain this to me?”source ↗
“My elderly parents rented the place out for a while. But the letting company "fixed" things and I'm starting to realise most of the "fixes" they made are bodjed”source ↗
“Thanks I'm.sure its my neighbours but not sure how to handle it”source ↗
“Saw this while doing some yard work. Not sure how long it’s been like this for.”source ↗
“Any idea what the pipe is for?”source ↗
“How bad is the damage? Any suggestions on getting this fixed?”source ↗
“Noticed some water on the bottom of the vanity and the right side moving upward was moist. Not sure where it could be coming from.”source ↗
“We’ve had a high water bill recently.”source ↗
“We will be calling a plumber tomorrow but just wanted to see if anyone here had ideas.”source ↗
“There is a pipe coming from our hot water heater that splits and goes to the outside of the house. I just noticed that when the shower is running the pipe that it leads to outside is leaking. This particular pipe appears to be useless? But I don't want to just cap it off and have water filled there all the time? Do I need this for some reason? Thanks.”source ↗
“I noticed a puddle in the corner of my basement. The source is this (it's in a very add and hard to reach spot, this is the best picture I could get).”source ↗
“I have 0 idea what I'm doing when it comes to this.”source ↗
Where this came up
People with this problem also raised
- 4How to tell if crusty residue on a basement pipe is a sewage leak
- 25How to identify unknown plumbing parts in a building
- 10How to find where an unmapped drainage pipe discharges
- 2Where is the black debris clogging my shower head coming from?
- 126How to fix a leaking water pipe in a tight space
- 12Is my outside unit leaking oil or condensation?