Announcement Announcement Module
Collapse
No announcement yet.
SDR pipe vs sch 40 pipe Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Re: SDR pipe vs sch 40 pipe

    I see 4" SDR 35 PVC commonly on both septic and sewer systems. Only outside the building, never inside. I don't do installs, just clear clogs, just know what I see and where I see it.

    It is definitely flimsier than sch40. I once fooled myself trying to locate a line; never saw a fitting so assumed it went straightish, but they had bent sdr35 in a long arc thru 135 degrees, lord knows why.

    I think cost is the main consideration. Also I have been told, though I am not sure I agree with the rationale, that SDR 35 is BETTER because it will flex a little if things settle and move with it rather than cracking. I have been told by an excavator I work with sometimes that one inspector was requiring him to concrete bends in sch 40, but not in sdr35. again lord knows why.
    This is my reminder to myself that no good will ever come from discussing politics or religion with anyone, ever.

    Comment


    • #17
      Re: SDR pipe vs sch 40 pipe

      Any pipe that you can distort the inside diameter of the pipe with just your bare hands.......will someday be job security thanks to the heavy earth matter above it, whether probably covered with grillage or not.

      I've removed this stuff 20+ years old that ovals, even though all 4 sides was covered with sand.

      If it doesn't bend it usually collapses with splintering down the sides, staying in tack at the fittings due to it's doubling up of material.


      Personally I think it should be banned as it's too susceptible to failure since you can change the physical properties of its intended design.

      SCH40 is what I feel is the best choice for underground but it comes with considerations as well. The pipe itself will endure longevity but stress points will cause the fittings to snap under strain over time due to constant temperature variances changing the molecular structure of plastic, making it brittle like glass.
      Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

      Comment


      • #18
        Re: SDR pipe vs sch 40 pipe

        SDR is used underground,due to its greater amount of deflection,then sch 40.

        With soil conditions known,the amount of pipe deformation can be computed and allowed for.With SDR,these values can be used regardless of size of pipe.

        With Sch 40,these values would be differant for every size,as the wall thickness is not in proportion to Diameter,giving differant load values for differant size pipe...

        Pipe,regardless what is made out of....steel,iron,plastic,copper,will do 1 of 2 things...it will either bend,or it will break.SDR 35 will bend more then sch 40...so the theory goes,less breaks with SDR.
        Last edited by UA22PLumberdude; 03-08-2008, 01:49 AM.

        Comment


        • #19
          Re: SDR pipe vs sch 40 pipe

          Originally posted by UA22PLumberdude View Post
          SDR is used underground,due to its greater amount of deflection,then sch 40.

          With soil conditions known,the amount of pipe deformation can be computed and allowed for.With SDR,these values can be used regardless of size of pipe.

          With Sch 40,these values would be differant for every size,as the wall thickness is not in proportion to Diameter,giving differant load values for differant size pipe...

          Pipe,regardless what is made out of....steel,iron,plastic,copper,will do 1 of 2 things...it will either bend,or it will break.SDR 35 will bend more then sch 40...so the theory goes,less breaks with SDR.
          I didn't know that. I assumed SDR was just cheaper and inferior, you are full of great plumbing knowledge.
          Water Heater Reviews & Water Heater Information

          Comment


          • #20
            Re: SDR pipe vs sch 40 pipe

            I do all my sewers in sch 40. I have dug up way too many SDR sewers that were all warped and sagging, backpitched and joints coming apart. Stuff just seems junky. Of course a big factor is proper installation, grading and tamping regardless of pipe.
            Water Heater Reviews & Water Heater Information

            Comment


            • #21
              Re: SDR pipe vs sch 40 pipe

              You guys down south have to remember that up North the ground freezes and heaves and moves up and down from season to season.
              sigpic

              Comment


              • #22
                Re: SDR pipe vs sch 40 pipe

                Originally posted by NHMaster3015 View Post
                You guys down south have to remember that up North the ground freezes and heaves and moves up and down from season to season.
                Especially this year. Our roads are like a roller coaster with the cost of a ride to town being 1 strut and 1 shock. When it warms up a bit more the cost will also include 1 tire for the pot hole you hit when trying to avoid another.
                INSIGHT PIPE is now Maine Drain Serving most of ME with no charge for travel! 207-431-6232 is nolonger a working # our NEW # is 207-355-1476
                Sewer main snaking (roto rooting). Sink clogs. Sewer backup. Pipe inspection/locating. No Dig trenchless repair. Root clog removal.We are NOT to replace your local Plumber, as we do not do plumbing. WE ARE YOUR DRAIN CLEANING EXPERTS!!! www.sewermaine.com waterville winslow bangor augusta skowhegan fairfield pittsfield oakland

                Comment


                • #23
                  Re: SDR pipe vs sch 40 pipe

                  Indeed, the frequency of freezing, thawing and flooding are awful this year in New England...my front end was just aligned 2 months ago and it feels like it's already going out again.
                  The idea of deflection and frost heaving adds up now...finally makes sense on why SDR is used on exterior drains.
                  I couldn't begin to imagine what ABS would be like on exterior undergrounds here.

                  Comment


                  • #24
                    Re: SDR pipe vs sch 40 pipe

                    SDR stands for Standard Dimension Ratio. It’s the ratio of the outside diameter of a pipe to the pipe wall thickness. In other words pipe that is rated SDR 35 has a diameter 35 times larger than its wall thickness; SDR 11 has an outside diameter 11 times larger than its wall thickness and so on.



                    SDR isn’t a type of pipe; it’s more of a method for rating the pipe stiffness and pressure. 3034 pipe (3034 is the ASTM standard by which PVC pipe is constructed. It’s the green pipe used in large construction projects) is available in various SDRs and therefore various strengths. 6” PVC pipe with an SDR of 17 has a thicker wall than 6” SCH 40 pipe.
                    On public works construction projects the pipe being referred to as SDR is usually 3034 with an SDR of 32.5 or 35. This is not thin walled pipe and it is less expensive than SCH 40. 3034 SDR35 exceeds all requirements for pipe stiffness, flexural strength and flexural modulus specified in most gravity sewer construction uses, but not for pressure applications. In Oregon, on public works projects, the most commonly used pressure rated pipe is C900 or C905 which is the AWWA standard for plastic pipe above 4”.

                    Comment


                    • #25
                      Re: SDR pipe vs sch 40 pipe

                      4 1/2 years later yet more info(kinda) Nobody ever looks at the date lol.
                      Seattle Drain Service

                      Comment

                      Working...
                      X