Drain pipe rotted under house, can someone look over my repair plan?

[tireshark]

I have a section of cast iron drain pipe that rotted out right under the middle of the house... im going to cut at each end of the house and replace with PVC, probably about 25 feet.

Wanted to install a clean out plug back at the sink, and possibly one right before it goes into the 4" sewer drain. I can do that with wye pieces right? Will use fernco couplers to join pvc to the cast iron. Here is a rough diagram, just wanted someone to check it out in case i missed something, or if there is an easier way to do it.

The #1 wye is the one i will for sure install, the #2 wye is optional because i dont know if it's really necessary (although i imagine the more clean out spots the better?).

http://i.imgur.com/ugOiTLz.png

Thanks!

p.s. i just realized i will probably need to tie the washer drain into this... so i will probably just use another wye to make that connection somewhere in the middle.

 

[phishfood]

I would replace every part of the cast iron pipe that you can get at, not just the section that is broken right now. Use transition bands instead of rubber Ferncos to transition between cast and plastic.

 

[tireshark]

thanks phish. i used the proflex silver couplings to join them together and everything went smooth.

the only section i didnt replace was this section that went into a 4 inch cast iron wye... i figured it might be a mess for me to tackle that, but i dug out all of the pipe and inspected it to make sure it was still solid.

http://i.imgur.com/guZvrYJ.jpg

 

[frodo]

that line looks pretty well stopped up. did yo dig that stuff out of there?

my advice, go ahead and replace thye 4"

 

[tireshark]

yeah i cleaned it out and put a cleanout connection there:

http://i.imgur.com/53i4IBk.jpg

i was thinking i would need to disconnect the pipe out of the wye, and that it would be tough to do... but i suppose i could have just cut through the 4" CI and replaced the wye as well... prob should have cut it out and replaced it, but that area is right next to the crawl space entrance so it will be easy to access if i need to replace it in the future.