Sched 40 or 30?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by HemiMoparGuy1981, Jul 10, 2008.

  1. HemiMoparGuy1981

    HemiMoparGuy1981 New Member

    Jul 10, 2008
    I'm having a disagreement with a friend of what pipe is proper for drainage from sink, tub and toilet. He says he has a friend who is a licensed plumber that says you can use sched 30 pipe. And truthfully, I don't really see why not. However a few things make me question it. Why have all the houses I have built, when I was a foreman for a construction company, have sched 40, I know the builders I worked for are so penny pinching, that if they could've gotten away with saving money by using sched 30, they would have. Also, an even better reason why I think it has to be sched 40 is that when I did septic tanks and fields, when the sewage enters the tank, it has to be sched 40, also when it leaves the tank is sched40 and the lead pipe and header has to be sched40, but then all the runs for the actual seepage is perforated sched 30. So it doesn't make any sense that the drainage from each fixture can be sched 30, but has to switch to sched 40 to leave the house and enter the tank, then to leave the tank to the septic field, then after that switch back to sched 30. I am in Michigan, if the codes vary that much. Any help will be greatly appreciated.
  2. TMB9862

    TMB9862 New Member

    Nov 12, 2006
    DWV has to be Sched 40
  3. Sponsor

    Sponsor Paid Advertisement

  4. HemiMoparGuy1981

    HemiMoparGuy1981 New Member

    Jul 10, 2008
    I'm sorry, I'm sure I know, but for whatever reason I cannot remember, as I do not do much plumbing...what is DMV?
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    It's DWV, drain, waste, vent...
  6. Southern Man

    Southern Man DIY Hillbilly

    Jun 27, 2008
    North Carolina
    Department of Motor Vehicles. Being a Mopar guy, I figured you'd know that. ;)
  7. construct30

    construct30 New Member

    Jun 16, 2007
    NorthWest PA
    The p traps can be thinner here, but nothing else. Some of the cheap tub overflows are thinner too, but I don't like them, many codes say no on the thinner traps and overflows too. Inside the house sch 40.
    Last edited: Jul 11, 2008
Similar Threads: Sched
Forum Title Date
Plumbing Forum, Professional & DIY Advice House main service question -sched 80 PVC or type L copper Jul 3, 2017
Plumbing Forum, Professional & DIY Advice Scheduled Maintenance: June 30th, 2014 Jun 9, 2014
Plumbing Forum, Professional & DIY Advice Gray schedule 40 Apr 5, 2014
Plumbing Forum, Professional & DIY Advice ABS or Sched. 40 PVC? Jun 19, 2013
Plumbing Forum, Professional & DIY Advice Schedule 20 for Tub Drain? Apr 13, 2013

Share This Page