The other day I got a call from the tenant in the basement apartment of my rental townhouse. He’s been having a wet carpet, and he pulled up the carpet to find a 10 inch vertical pipe, the top of which is almost level with the concrete surface of the floor. The pipe is filled with sand, and the sand is wet, so it’s likely the water is coming from there.
Question is what exactly is this pipe, and what purpose does it serve and whether I can just cap it off somehow? (I’m wondering if there’s possibly some other pipe buried somewhere in the sand.)
I spoke to a guy who is a sort-of plumber (he specializes more in snaking toilets and sinks than laying pipework) and he said it was a “big job” to take care of this and threw in a bunch of plumbing jargon, and said he couldn’t be more definitive unless he came down and saw it. So I figured maybe someone else here knows.
I vaguely remember dealing with a somewhat similar hole in a cement floor in the basement of a former County Home where I had a summer job. The pipe/hole wasn’t very deep and had a valve at the bottom that controlled flow through other pipes beneath the cement floor. Our “hole” just had a piece of wood over it because the area was just used for storage. Maybe somebody filled yours with sand so that carpet could be laid over it without permanently blocking access to it.
Could it be a rough-in for a toilet? The diameter sounds about right. Maybe whoever built the place planned on putting a bathroom down there at some point in the future.
Ten inches in diameter?! That’s way too large to be a floor drain or a toilet. A stand-alone shower drain is only 2" and I’ve never seen anything larger than a 4" standpipe in a residence. The only thing I can come up with is that perhaps it was used as protective sleeve for some other, smaller pipe at one time. I’d dig out about six inches of the sand, mix up a small batch of concrete and seal it for good.
I think Scumpup may have it right. It could be a valve box for a shut off valve that was abandoned in place. If it is, then perhaps the valve is leaking. If that’s the case, that should be fixed (or better yet, removed and relocated if it is still needed) before it is covered in concrete. Otherwise you are just going to have bigger problems later with a leak under the floor.
If it is a leaking valve, the bad news is that you will probably need to break open the floor and dig. The good news is you will know exactly where to dig.
Without knowing where in the world this is and when it was built, we’re all guessing.
My vote is it’s a sump pit. Just a rather small one. Which might have been 100% typical contruction technique there and then.
IMO, the worst possible thing to do would be to seal it up before you understand what it is. Unless you intend to sell the house in the next year or so before that “repair” causes further damage.
If they did just dump sand in a sump pit and lay carpet over it, I wonder how many other excellent engineering features are hidden in this basement-converted-to-apartment.
I spoke to a handyman guy I know and he speculated sump pit until I mentioned that it was located about 8-9 feet away from the exterior wall of the house. He said that sump pits are almost always located next to the exterior wall, and he pronounced himself stumped.
I sent an email to several homeowners who live in that same development, thinking they might have the same feature in their own basements and know what it is. Only one guy responded so far, and he said he didn’t know but also guessed sump pit.
So do I. (I believe the conversion was done by the same guy who originally built the entire subdivision, but he did it subseqent to building the upstairs apartment.)
Do you have any blueprints for the house? Have you asked the building department if they have any records from when the house was built? It might be documented somewhere.
(I believe the conversion was done by the same guy who originally built the entire subdivision, but he did it subseqent to building the upstairs apartment.)