(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 6 of 6

Thread: Replace Cast Iron DWV System with Plastic?

  1. #1

    Default Replace Cast Iron DWV System with Plastic?

    I'm in the process of replacing an entire bathroom - had to rip out to the floor joists due to the shower pan leaking, etc. The home was built in 1975 so the DWV is a no-hub cast iron system. My main soil stack is in close proximity to the toilet, so it could be replaced, relatively easily, if needed. When I removed the no-hub fittings around the shower and toilet drains, I noticed the rubber gaskets surrounding the fittings are dry and starting to crack, when removing them. The other fittings going to the main soil stack appear to be in tack with no leaks, etc.

    My question: Should I replace the old cast iron system with plastic? Should I just replace the gaskets surrounding the existing fittings or would I be ok to leave well enough alone and not do anything? What is the average life of a cast iron DWV system? Any thoughts? Thanks for any input.

  2. #2
    DIY Senior Member finnegan's Avatar
    Join Date
    Aug 2005
    Location
    CT
    Posts
    250

    Default

    The average life of a cast iron is pretty much forever. There is no good reason to replace a no hub cast iron system that is not leaking. Assuming that the system was properly installed with the correct no hub couplings, I would leave it alone. If you want to replace the visable and accessable couplings go for it.

  3. #3
    Plumber Cass's Avatar
    Join Date
    Nov 2005
    Location
    Ohio
    Posts
    5,984

    Default

    Personaly, I would change over to plastic if/while the floor is open. As you can see the rubber in the couplings doesn't last. You could probably leave it alone and be fine but I would change it over, and plastic is forever. The stack I wouldn't change unless there was a problem.

  4. #4
    DIY Senior Member lithnights's Avatar
    Join Date
    Nov 2005
    Location
    PA
    Posts
    143

    Default

    But what about noise effects? We did rework in our home and had to have the main waste stack coming from the 2nd floor come right through a main wall in our 1st floor where we spent much of our time.

    Because of the noise (cast iron is quieter), I had them put in cast iron instead of the PVC. And I'm glad I did. I can hear the difference too. The section of the upstairs plumbing that is PVC (horizontal pieces..from shower to main stack) is much louder than the cast iron (vertical stack).

  5. #5
    DIY Senior Member finnegan's Avatar
    Join Date
    Aug 2005
    Location
    CT
    Posts
    250

    Default

    Thre are a huge number of no hub connections in use all over the country. it is a very reliable connection. Generally a cast iron no hub system is considered an upgrade from pvc.

    Last edited by Terry; 11-07-2013 at 03:47 PM.

  6. #6
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,624

    Default gaskets

    After a no-hub systems have been installed for a while the only rubber that is important is the small ring between the pipes, and that is usually so tight that when you remove the metal band and try to remove the rubber that ring tears off and you have to pry it out of the joint. But it is also almost impossible to get the new band to slide into that groove so it fits smoothly. In other words, do not disturb any No-Hub connection that is not leaking, or unless you intend to change the piping.

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
  •