Results 1 to 12 of 12
  1. #1
    Join Date
    Mar 2007
    Location
    Atlanta, Georgia
    Posts
    1,078

    Default Steeply sloped waste pipe

    I seem to remember that waste pipe is allowed to be installed vertically or near horizontal (1/4" per ft slope) only. I read something years ago that said steeply angled pipes cause water to flow too quickly and can leave solids behind forming clogs.

    The past two days the main waste line was angled 45-60 degrees.

    Can you have a sharply angled waste line?

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    Inspection Referral SOC
    "The Code is not a peak to reach but a foundation to build from."

  2. #2
    Join Date
    Mar 2007
    Location
    Chicago, IL
    Posts
    2,797

    Default Re: Steeply sloped waste pipe

    As I remember it, any slope between 45 degrees and vertical is acceptable.

    But I don't have a cite for that.


    Michael Thomas
    Paragon Property Services Inc., Chicago IL
    http://paragoninspects.com

  3. #3
    Mark T. Denton's Avatar
    Mark T. Denton Guest

    Default Re: Steeply sloped waste pipe

    On this short of a run the slope should not be a problem. Anything more than 45 degrees is considered verical. What might be a problem is the lack of support. Both the PVC & ABS need supports 4' o/c. I don't see any in the photo's, but they might just be out of view. I would also check the glue on the ABS joints. I seem to remember there have been issues with it. Good luck.


  4. #4
    Join Date
    Nov 2009
    Location
    St Paul, MN
    Posts
    1,628

    Default Re: Steeply sloped waste pipe

    Quote Originally Posted by Bruce Ramsey View Post
    I seem to remember that waste pipe is allowed to be installed vertically or near horizontal (1/4" per ft slope) only. I read something years ago that said steeply angled pipes cause water to flow too quickly and can leave solids behind forming clogs.

    The past two days the main waste line was angled 45-60 degrees.

    Can you have a sharply angled waste line?
    It depends if it's black water or gray water. If it's only for gray water it shouldn't be a problem.

    MinnesotaHomeInspectors.com
    Minnesota Home Inspectors LLC
    ASHI #242887 mnradontesting.com

  5. #5
    Join Date
    Mar 2007
    Location
    Fuquay Varina, NC
    Posts
    1,072

    Default Re: Steeply sloped waste pipe

    steeply angled pipes cause water to flow too quickly and can leave solids behind forming clogs.
    I remember that also. but if it's to steep the **** would just fall through the pipe not needing water. Maybe the rush of water could suck traps dry. Would like to here more on this though.

    Mike Schulz License 393
    Affordable Home Inspections
    www.houseinspections.com

  6. #6
    Join Date
    Feb 2008
    Location
    Chicago IL
    Posts
    1,984

    Default Re: Steeply sloped waste pipe

    I wouldn't be concerned about those short runs and see them as essentially vertical drops. 1/4" per foot on horizontal runs as others have mentioned. There should be a hanger on either side of those 45's though for support.

    www.aic-chicago.com
    773/844-4AIC
    "The Code is not a ceiling to reach but a floor to work up from"

  7. #7
    Ted Menelly's Avatar
    Ted Menelly Guest

    Default Re: Steeply sloped waste pipe

    Quote Originally Posted by Bruce Ramsey View Post
    I seem to remember that waste pipe is allowed to be installed vertically or near horizontal (1/4" per ft slope) only. I read something years ago that said steeply angled pipes cause water to flow too quickly and can leave solids behind forming clogs.

    The past two days the main waste line was angled 45-60 degrees.

    Can you have a sharply angled waste line?

    Yes you can


  8. #8
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,243

    Default Re: Steeply sloped waste pipe

    Quote Originally Posted by Markus Keller View Post
    There should be a hanger on either side of those 45's though for support.

    Actually, plastic pipe should be supported at spacings of no greater than 4 feet, except for CPVC in sizes 1" and smaller which need to be supported at spacings of no greater than 3 feet.

    Plastic piping does not, however, need to be supported at each fitting, although it basically works out that way because if there is no greater than 4 feet between supports there will be two supports near each fitting, or one right at a fitting and the next support within 4 feet of the first support (which would be less than 4 feet from the fitting).

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  9. #9
    Join Date
    Feb 2009
    Location
    Southern Vancouver Island
    Posts
    4,546

    Default Re: Steeply sloped waste pipe

    Quote Originally Posted by Jerry Peck View Post
    Actually, plastic pipe should be supported at spacings of no greater than 4 feet, except for CPVC in sizes 1" and smaller which need to be supported at spacings of no greater than 3 feet.
    I gues string's no good, huh?

    A few pics of typical plumber's art for you'all. How many gallons of crud have travelled through that angled copper pipe? None, if it's a vent.

    The last one, the drain for the PRVs is propped up with a piece of ABS resting on the flooring at the left elbow. Very creative new construction.

    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    Last edited by John Kogel; 01-31-2010 at 11:02 PM.

  10. #10
    Join Date
    Jul 2008
    Location
    Snowbird (this means I'm retired and migrate between locations), FL/MI
    Posts
    4,086

    Default Re: Steeply sloped waste pipe

    Minimum slope for trade size is just that, minimum. Ideal provides proper scour (friction), displacement of air, with a minimum of pipe errosion. The norm is to maintain a certain slope for the majority of the run of the drain, fixture branch, etc. and offset adjust at the downstream, as gravity does a good a job of moving solids too (as well as water velocity & friction). IIRC trade size =/< 3 @ 1/4"/ft is a velocity of about 3 ft/second for water.

    As long as the necessary and required cleanouts are provided, venting, and support it should not be a problem for drainage, errosion & useful life may be reduced.

    A back to basics primer on the subject, this link is to a similarly titled article in PMEngineer (clickable link below). Hope you find it helpful:

    Back to Basics: Sanitary Drainage Systems - Feature Articles - PM Engineer____


  11. #11

    Default Re: Steeply sloped waste pipe

    Quote Originally Posted by John Kogel View Post
    I gues string's no good, huh?

    A few pics of typical plumber's art for you'all. How many gallons of crud have travelled through that angled copper pipe? None, if it's a vent.

    The last one, the drain for the PRVs is propped up with a piece of ABS resting on the flooring at the left elbow. Very creative new construction.
    There is such a thing as copper DWV piping. Marked in yellow I think. If it is a vent, its wrong. It cannot be below the waste inlet from another fixture.
    Dana

    True Professionals, Inc. Property Consultant
    877-466-8504

  12. #12
    Join Date
    Jul 2008
    Location
    Snowbird (this means I'm retired and migrate between locations), FL/MI
    Posts
    4,086

    Default Re: Steeply sloped waste pipe

    Quote Originally Posted by Dana Bostick View Post
    There is such a thing as copper DWV piping. Marked in yellow I think. If it is a vent, its wrong. It cannot be below the waste inlet from another fixture.
    Dana
    DB,

    When I see yellow marked copper I think GAS (or other hazard possibly petroleum, oil, steam, etc.) not sanitary, gray, or storm water; that's what green markings are for (liquids, inherently low hazard).

    Last edited by H.G. Watson, Sr.; 02-01-2010 at 02:11 PM.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •