CI Plumbing Stack to Sewer

New here and looking for some advice.

My house is probably close to 100 yrs old and i need to replace the 4" cast iron stack... probably doing it myself. Dug up some of the basement floor and found where the clay? & cast iron pipe meet. Here is the connection... there are a couple more pics also. Not sure what that tapered piece is but it measures about 7" OD at the large end and 6" OD at the smaller end. I'm trying to find a suitable place to connect ABS with a coupling. Just for reference, that tapered piece is the farthest i've dug away from the CI stack. All the pics are of the sewer between the tapered piece and the stack

The cast iron stack cracked just above the floor and i need to replace it. So i was going to replace it with ABS - 5 feet above ground to somewhere along the sewer. I will support the stack with 4" riser clamps before cutting. I think i need to dig a little longer to find a straight section to connect a coupling.

Could use some input....

If I was you I would stay far from the clay. Clay pipe is very brittle and trying to cut it could cause a crack to run further than you want to replace.

Try to keep your work away from the clay pipe. The ferncos that you need to connect to clay can be a bit hard to find. If you intend to tackle the clay find a place that sells the ferncos you will need first.

not sure if i have a choice from staying away from the clay... someone suggested to me that the cone shaped piece is vetrified clay and the stuff between that and the CI stack is also cast iron with mineral deposits around it. Not sure if that's any better...

The crack in the stack is close to the floor and i don't have much to connect to right below the floor so i was going for a horizontal section and trying to find my best option...

Getting something to connect to cast iron is simple, they sell all you need at the big home stores. Clay connectors are sold at some supply houses.

the mineral deposits can be removed by scraping them off carefully with a chisel or screw driver.

which is best to make the sewer connection - clay pipe or cast iron (after removing deposits), considering both their age?

also, how long do you have to wait for abs solvent to dry before tossing water down?

lukus said:

which is best to make the sewer connection - clay pipe or cast iron (after removing deposits), considering both their age?

also, how long do you have to wait for abs solvent to dry before tossing water down?

Click to expand...

If I was you I would connect to the cast Iron. You only need to remove the scale about 2" from the end you cut. The clay would be easy but if it cracks you might be chasing to a good spot. Plus getting a fernco might be hard for the clay pipe never seen plastic to what ever size clay in the box stores.
The scale will come off with little effort. you just need to get under it and scrape.

You don't need to wait long for abs glue to set just give it a minute or two.

i cracked the cast iron when i was trying to remove the scale so i went for the clay. It cracked on he first try and the coupling for clay to plastic was stock at Home Depot. It took me a long time to dig the pipe out though. Finally finished and not i'm gonna go shower... hope it doesn't leak... hehehe.

Thanks for the advice

Make sure to take a long hot shower .

clay

How did you cut the clay, and where did you connect to it? The tapered thing is probably a 6" x 4" reducer and you would have had to cut either before or after it to make a proper joint.

cwhyu2 said:

Make sure to take a long hot shower .

Click to expand...

Showered twice

I cut the clay beyond the tapered section... cut a straight section with a soil pipe cutter and used a clay-to-plastic coupling. I actually just broke the tapered clay section apart with a hammer.