Rough-in for concrete over PVC DWV

Discussion in 'General Plumbing Help' started by jmprPF, Feb 28, 2011.

  1. Feb 28, 2011 #1

    jmprPF

    jmprPF

    jmprPF

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    What is standard practice at the rough-in stage for PVC DWV piping that penetrates a slab floor? In particular, how are vents and drains terminated in (or above or below) the slab before the concrete work is done?

    Are all drains/vents brought through the slab and left projecting above the level of the concrete, a foot or so? (Presumably toilet drains are then cut off to finished floor level.) Or is there some standard practice that leaves the piping at or below concrete level at rough-in, and then the piping is extended through the slab after the concrete work and structural framing are completed?

    I'm an amateur with some experience with under-slab DWV plumbing but in the past have used what must be non-standard approaches to this question. (I believe I'm adequately informed/experienced with pipe sizing and pipe layouts including under-slab practices, and can satisfy local building codes.)
     
  2. Mar 1, 2011 #2

    phishfood

    phishfood

    phishfood

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    Water closets a few inches above the concrete, sink, lavatory, and laundry drains and vents ~24" above. The only time I terminate flush with concrete is in types of construction that utilize rollout forms for pouring upper floors.

    Under slab rough-in can seem deceptively simple, but it is really easy to screw up. And with layoffs rampant in building departments as local governments try to balance their budgets, don't count on the inspector to catch every issue. If you have a question, do not hesitate to ask us.
     
  3. Mar 1, 2011 #3

    PrecisionPlumbing

    PrecisionPlumbing

    PrecisionPlumbing

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    all piping needs to be sleeved in plasic where concrete will touch and stubbed 24" above the floor
     
  4. Mar 8, 2011 #4

    jmprPF

    jmprPF

    jmprPF

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    Thanks for the help with this topic!
     

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