I recently purchased a newly built house. It has an unfinished basement. There is a white pvc pipe that comes from the floor. It is about 4 feet tall. Out of it comes a sewer smell. Some days worse than others.

  1. What is this pipe?
  2. How can I stop the smell from coming into my basement?

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  • What?! Can you post a photo? – paul Sep 8 '18 at 13:50
  • 1
    Pictures are worth 1000 words. What diameter? Is there any others another size nearby? Sounds like a rough-in for a bathroom that didn’t get capped off. Post a pic of it, and the area it’s in overall and we’ll be able to see much more. – Tyson Sep 8 '18 at 13:51
  • I wish I could put a pic. When I upload a pic it fails. It's 3.5 inch diameter – Terry Sep 8 '18 at 13:55
  • Upload to imgur.com then, and just post a link here. (You don’t need an imgur account, just click upload and do it without). – Tyson Sep 8 '18 at 13:56
  • On the pipe is written royal plumbing solutions BSP PVC 12364 sewer – Terry Sep 8 '18 at 13:56

My basement has a 4 inch perforated drain pipe in 16 inches of washed septic gravel under the concrete floor. It is reduced to a smaller diameter and taken up to the roof. It is to vent any radon or any other gas that might be under the floor. Could the OP's pipe be a vent?

  • 1
    +1 for thinking of radon. Yes, the smell might not be sewer smell but stale soil smell coming in the perf pipe and waffing into the house. Blocking the pipe could stop the radon venting process. I’d extend it through the roof. Often we’ll add an exhaust fan on the pipe after a few years if the radon level does not go down. – Lee Sam Sep 8 '18 at 17:38
  • I don't know if it's noteworthy, but the other day I noticed it smelled much worse than normal. Bad enough that I went upstairs. I put my nose into that pipe and I felt air coming out of it. That air coming out of it also smelled awful. The roughing for the bathroom is in a separate area from that pipe. – Terry Sep 8 '18 at 20:59
  • We're all speculating here. If it's a newly built house, ask the builder what the pipe is. – fixer1234 Sep 8 '18 at 21:46
  • Based on your comment, I think it's a vent that should be extended up then out of the house (roof or whereever, depending on how technical you want to get.) but get it vented outdoors for sure. – ssaltman Nov 22 '18 at 18:07

It may be a stubbed out pipe for a future toilet that is plumbed to either the sewage line or an underground sewage waste tank. I have one of these sticking out in my basement. Though I also have a stubbed out drain for a sink and bath tube close by.

I'd cut the pipe even, right below the crack and glue a cap on it.


Looks like a Radon vent. It was probably put in when the basement floor was poured and then should have been extended up through roof but never was (or maybe if you don't have a radon issue then just capped??). Below is the picture of my vent in my basement which was just poured this year. Since you just purchased the newly built house talk to the builder and see what they say.

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