I'm in the middle of a gut reno on a kitchen and in the process have completely exposed the cast-iron waste system of two upstairs bathrooms that sit above the kitchen. It's about 20-30 years old of the lead soldered variety. Lot's of fittings and therefore lots of joints to possibly go bad over time.

In correcting a structural sag in the kitchen floor/ceiling, one of the toilets has started to leak when flushed and one tub has started dripping when used.

I can either correct these two individual problems and hope no more crop up or simply rip out all that cast iron and replace it with new PVC. Chances are it will never be this easy to get at the pipes again.

Aside from noise... why shouldn't I replace the CI with PVC? Any thoughts?

 

Same story here, but in the bathroom. Getting rid of the pink Tub and Toilet.
I removed the sink last, and the shutoff valve leaked. Shut off the house water, put a new valve on. The threads of the half-inch galvanized pipe were 1/3 gone, and the interior was soo rusty that I doubt I could drop a Sharpie pen through it.
With the drywall out, it'd be a shame to cover up old plumbing. Learned to "sweat copper", and added 4 days/ $250 to the project. Cheaper than a plumber... and now was as good a time as any.
I put a slight pressure on a cast iron p-trap, that drains the washing maching on the other side of the wall. It broke! Old rust, perhaps old damage. Perhaps held together by the paint.

I don't regret it, and pass my experience on to encourage the timely work.
The guys at the store looked at me in horror when I asked for a cast iron replacement. Steered me to the ABS rack. Except for 0 (zero) working time, glueing ABS together was the most fun I've had in the last 4 days.

 

Aside from noise (and it will be NOISY) can't think of any downside. I have always used ABS as opposed to PVC, but don't know of advantages/disadvantages-- maybe only ABS legal in CA.--just never see 3"-4" pvc.
chuck

 

Chuck,
Here in NY it's the opposite. You hardly ever see ABS in the home improvement stores... just PVC... in every size you could imagine ;-)

 

If it was me, I'd rip out everything that I thought could ever go bad and replace.
I'd do water, drains, and even electrical. But this is just me.

If you decide to rip out the cast iron. Wear safety glasses and remember IT IS HEAVY! Don't bonk yourself in the head.

Here in America's Heartland, you can use either ABS or PVC depending on which city and code you fall under.

 

notubo...

that's how I feel as well. And that's the way I'm leaning myself. I already replaced the old brass supply lines with copper. The old cast iron and clay sewer main with Schedule 80 PVC (real thick stuff) and most of the electrical. The only old stuff left is the c.i. waste pipe in the ceiling.

I posted just in case some expert would chime in and say... "Hold on there numb-nuts! You should leave the cast iron in there cause PVC has a tendency to disintegrate when it contacts an inverse sub-space field or a phased tachion pulse."

(hopeless star trek fan... sorry)