Help with trap configuration

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by thebordella, Nov 19, 2009.

  1. thebordella

    thebordella New Member

    Messages:
    22
    Location:
    Ithaca, NY
    Hi,

    I have nearly completed my (first) half-bathroom renovation: new floor, new paint, new toilet, and...new vanity? Almost.

    When I removed the old vanity/sink, I cut out the old trap. As advised by members on this forum, I then cut back to the drain pipe coming out of the wall and attached a standard P-trap.

    However, when I tried to rough in my vanity cabinet, I discovered that the P-trap hangs too low to clear the lower shelf of the vanity. The wall pipe itself clears the shelf but the downward hang of the P-trap is about 3 inches too low.

    Whoever installed the (very old) vanity/sink that I tore out seemed to have encountered the same issue. You can see their solution in the first attached picture -- notice that there is an elbow on the straight wall pipe which turns up, then straight, then right, and then into what looks like a typical P-trap.

    If I recreated this configuration it would clear my vanity. But it looks non-standard. Then again, I am very new at all this. Can anyone describe what they did here and whether I could re-create this configuration?

    Note that most of what you see in that picture is long gone, having been torn out.

    The second photo shows the P-trap I added (before redoing the room -- it looks much nicer now!). But it hangs too low for the vanity.

    Appreciate your thoughts!

    thanks,
    Aaron

    Attached Files:

  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,237
    Location:
    Cave Creek, Arizona
    drain

    Is that a backwater/check valve? If so what is it doing there? IF you do not raise the drain in the wall, and that can be difficult depending on how the pipe is arranged in the wall, ALL you can do is cut a slot for the trap to hang into.
  3. thebordella

    thebordella New Member

    Messages:
    22
    Location:
    Ithaca, NY
    Apologies for my ignorance -- I don't know what a backwater/check valve is.

    The only two valves I am familiar with in that first picture are the hot and cold cutoff valves.

    I could cut a slot in the new vanity for the low-hanging trap, but before I do, I thought I'd ask about the old configuration. More specifically, what's wrong with it? Why can't I do that? (Again, asking this totally naively).

    -Aaron

  4. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,395
    Location:
    Yakima WA
    In the second photo we can see some kind of an extra fitting/device in the drain line. It appears to have a cap on top which leads us to think it is some kind of a check valve. It should not be there.
  5. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    It's an s-trap, and could possibly siphon the trap dry.
  6. Inspektor Ludwig

    Inspektor Ludwig Journeyman/Inspector

    Messages:
    167
    Location:
    In the good ol' UPC
    That little white thingy on the trap arm is an "anti-siphon" port of somekind. I think it's just a built in Studor vent. But beware.....there's some new products that are trying to get approval in my jurisdiciton. I don't know the names but it's a swing check trap arm that "eliminates the sewer gas smell caused by faulty trap primers and dry traps". It eliminates the trap. I've seen two versions, one goes on the tailpiece of a floor drain and acts like a spring check, the other is designed to go on the trap arm of a sink or lav. Any other plumbers seen these?
    We said "NO WAY" thank goodness but every few months they try again. For the trap issue, as the guys said earlier, you'll either have to open the wall and raise or lower the waste inlet or you'll have to cut into the shelves to make room.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,237
    Location:
    Cave Creek, Arizona
    "thing"

    IT is NOT an "S" trap, and from its appearance it is NOT a Studor or similar vent. It LOOKS like a backwater/check valve, but if so, it is NOT a replacement, or substitution for a trap. It is an ADDITION to the trap, and a poor idea at best. It also has NO function, unless there is also one on the toilet to prevent backflow flooding.
  8. Wrong. Image #1 shows an S trap that was removed. The other thing that they are calling "it" is in Image #2.
  9. Please define "hangs too low". Your image #2 shows a P trap at the right place.

    From there you can Route Your Pipe any way you want, to reach the sink. So you could send a pipe straight up, to a tight elbow, and then over horizontally to another tight elbow under the sink drain tailpiece.

    Also, do you know that a P trap can double back on itself? It doesn't have to look like the letter P on its side. It can be a squiggle. You can turn the J part of it back towards the back wall. Try this, if you want to get the riser pipe to be located closer to the wall.

    Hope this helps.
  10. Inspektor Ludwig

    Inspektor Ludwig Journeyman/Inspector

    Messages:
    167
    Location:
    In the good ol' UPC
    AHA! I knew I had seen that trap thingy before,
    it's a Genova "NovaVent" Anti-Siphon Trap. Google it and you'll see what "innovative" ideas plumbers are up against.

    Attached Files:

    Last edited by a moderator: Nov 20, 2009
  11. Doherty Plumbing

    Doherty Plumbing Journeyman & Gas Fitter

    Messages:
    810
    Location:
    Penticton, BC
    I have seen the spring type checks you speak of for floor drains. They actually work quite well. Are they ideal for areas where a trap primer would work great? No. But they're good for situations that warrant their use.

    The other type I have no seen.
  12. Inspektor Ludwig

    Inspektor Ludwig Journeyman/Inspector

    Messages:
    167
    Location:
    In the good ol' UPC
    Terry,
    thanks for adding the pic. I'm a certified computer dummy. I really thought all the clicking and copying garbage I was trying to do actually worked! LMAO:D
  13. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    The ACE hardware store sells them, HD and Lowes probably do also. Are they code compliant? Unfortunately......................................................................................... yes
  14. Inspektor Ludwig

    Inspektor Ludwig Journeyman/Inspector

    Messages:
    167
    Location:
    In the good ol' UPC
    Not where I'm at. We'd consider that to be an aav and therefore it would need to be installed per code requirements for drainage fittings.
  15. Doherty Plumbing

    Doherty Plumbing Journeyman & Gas Fitter

    Messages:
    810
    Location:
    Penticton, BC
    You consider them an AAV? How? They're upstream of a trap so they're not vents.......
  16. Inspektor Ludwig

    Inspektor Ludwig Journeyman/Inspector

    Messages:
    167
    Location:
    In the good ol' UPC
    D,
    I just read your last post on here, I think we were talking about 2 different things. The anti siphon on the trap arm is the one I'm talking about. The ones that go on the tailpiece I think provide a good answer to floor drains that have a dry trap problem.:D
  17. Doherty Plumbing

    Doherty Plumbing Journeyman & Gas Fitter

    Messages:
    810
    Location:
    Penticton, BC
    oh ok. I can't remember even seeing an anti-siphon device in use on a floor drain before. We use the spring and bladder type.
  18. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,237
    Location:
    Cave Creek, Arizona
    novavent

    They do not show pictures of their products, but state that the "NovaVent" comes in sizes from 3" to 24" which would not be appropriate for a lavatory drain.
  19. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    I'm no plumber but I'd go with the previous guys solution. It appears to have worked and it's in the vanity so no one sees it.
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