P-trap connection

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by azsun1411, Aug 22, 2006.

  1. azsun1411

    azsun1411 New Member

    Aug 15, 2006
    Putting in new mud-floor tile shower. After extending sewer line to center of shower, the line will only be about 2 inches below top of slab (not below the slab). My concern is, that to put a new p-trap under new shower drain, I may not be able to connect the p-trap directly to the sewer line. With the shower drain flange resting on slab, the shower drain connection may extend down too low to allow the p-trap to connect directly to the sewer line.

    As long as the top of the shower drain is about 2 inches above the slab and the sewer line is about 2 inches below "top" of slab, can I place the p-trap
    lower and connect to sewer line with short pipe riser and elbow? It seems that only difference is that the p-trap may hold more water than if conncected directly to sewer line.

    Asked question because when I removed the tub, the p-trab was conncected directly to sewer line and all of my sink p-traps are connected directly.

    Also, is it ok to fill in around the sewer line with concrete, in order to fill area in the slab that needs to be cut away.

    Don't think I explained myself well in previous posting and not sure this is ok either. Appreciate your help!
  2. Mike Swearingen

    Mike Swearingen New Member

    Jan 12, 2005
    Independent Real Estate Broker
    On Albemarle Sound In Northeastern NC
    Water does not flow (drain) uphill. I'm not a pro plumber, but if I understand what you're wanting to do, it won't work properly.
    All drain lines should slope 1/4" per linear foot toward the main drain, and tie in wherever necessary, or you're going to have water backing up in the shower.
    Plan "B".
    Good Luck!
  3. Sponsor

    Sponsor Paid Advertisement

  4. hj

    hj Moderator & Master Plumber Staff Member

    Aug 31, 2004
    Cave Creek, Arizona

    IF you are doing the shower floor the normal way, it will be about 2-3 inches above the slab. The way the "P" trap is constructed it will have plenty of room in the riser to set your drain's flange even with the slab.
  5. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Aug 23, 2005
    I&C Engineer (mostly WWTP)
    Columbus, OH
    What kind of normal shower involves locating the drain 2 - 3 inches above the slab? :confused:

    I think what he is saying is he wants to raise the discharge of the p-trap to meet the existing pipe. Then it's all downhill from there. As a result, more water will be sitting in the P-trap than it typically would. All connections would be below the slab. No uphill running water.

  6. prashster

    prashster New Member

    Dec 7, 2005
    Can you draw a picture? As long as no portion of the drain is above the shower flange and there's an average fall of 1/4" per ft from the flange and the downstream side of the trap is below the flange, it should be ok.
Similar Threads: P-trap connection
Forum Title Date
Plumbing Forum, Professional & DIY Advice Leaky P-Trap Tailpiece connection to Drain May 24, 2015
Plumbing Forum, Professional & DIY Advice kitchen p-trap to wall connection Mar 6, 2008
Plumbing Forum, Professional & DIY Advice Concern for basement p-trap connection to main line Apr 5, 2007
Plumbing Forum, Professional & DIY Advice Leak at P-trap/drain connection with new kitchen sink Feb 27, 2007
Plumbing Forum, Professional & DIY Advice Must p-trap be directly under shower or can it be 9 feet away? Oct 28, 2017

Share This Page