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Community and Q&A

Sewer smell

User avatar
Joshua Lloyd | Posted in General Questions on

So in the summer only we have what can be a strong sewer smell in the unfinished part of the basement. What I don’t understand is the smell is only present in the summer time, not the winter. Following the smell I believe I have located the source which is under a shower in a bathroom that was renovated before we moved into the home. Everything is dry around the plumbing, but am wondering if it could possibly be coming from the flexible T fitting where the new PVC drain line and old copper drain line connect. Has anyone had experiences with these connections not working well.

And actually as I am typing this I am wondering where my vent stack is. With hotter temperatures outside, there may not be enough draw in this particular area to remove the gases.

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  1. User avatar
    Joshua Lloyd | | #1

    Here is a picture of the connection in question. This is after the P-Trap.

  2. User avatar
    James Morgan | | #2

    Is there a floor drain in the area in question? The trap may dry out in summer.

  3. Gordon Taylor | | #3
  4. User avatar GBA Editor
    Martin Holladay | | #4

    If the shower has a P-trap, make sure it is full of water. You'll have to pour some water down the drain every few months to make up for evaporation.

  5. User avatar
    Joshua Lloyd | | #5

    To the right is the shower floor drain that gets used every other day. There is a floor drain at my feet from where the picture is taken fron, but the a/c condensate line drains into it. So it never dries out.

  6. David Meiland | | #6

    Those rubber fittings seem to me to work fine. Any reason to suspect it?

    I had a situation like that in a customer's house. It eventually turned out that the original builder had left an open pipe in the wall. We used a salvaged bath fan and smoke bombs to inject smoke into the DWV system to figure it out.

  7. Tom May | | #7

    There should be a vent pipe after the ptrap that ties into the rest of the venting or out the roof. If there is no vent between the ptrap and the connection you show, water can be syphoned out of the trap thus allowing sewer gas to rise up out of the shower drain or even the poor connection shown. the trap on the floor drain could also be drying up if not used.

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