The best advice I have so far is to drill a series of holes on the
circle that rpresents the new opening in the cast iron and then
connect the holes (scroll saw, sawzall, rotary cutting tool?).

Thanks for your consideration!

Al


Al

I read the entire thread before responding

Your best and easiest path to success is get a group of Torch Blades (trademark
of Milwaukee) and a Sawzall.

The Torch Blades cut cast iron like it was just steel. It may two or three
blades to do both cuts. I could do it with one but I have been using a
sawzall for 30 plus years.

You have indicated that you have the upper portion of the stack supported.

I dont recall if the stack is 3 or 4" but get the correct Wye either 3 x 3 or
4 x 3 and add at least 6 " of PVC to both of the runs of the Wye and add about
1/4" to the total developed length and make your two cuts.

While you are at home cheapo or wherever you shop for plumbing stuff pick up
two Fernco's for the stack diameter. Not No-Hub. Not some other cheap
junk...Make sure the name Fernco is on the rubber sleeve.

A Fernco is a Rubber Sleeve that will fit over your cast iron (take note of
whether on not your cast iron is XH or not).

You have now assembled your PVC Wye with a 6" piece of Sch 40 PVC glued into
each run of the Wye.

You have sucessfully cut out the proper length of cast iron leaving at least 3"
of cast iron sticking out of any fitting so you can slide the fernco over the
cast iron.

You now drive back to the hardware store and get the cast iron soap I forgot
above.
Cast Iron soap is a very slimey substance that allows rubber to slide over PVC
and cast iron.

Liquid dish detergent works in a pinch

Open the stainless steel clamps on the
fernco's ...not completely leave the last little bit of the slotted band
engaged in the screw portion of the band.

soap the inside of the fernco with the slimey cast iron soap... get the entire
insides of the fernco semi soapy...apply some soap to the outside of the PVC
pieces sticking out of the runs of your Wye.

Slide the Fernco over both ends of your PVC assembly until the ends of the
ferncos are about 1/2" past the ends of the PVC.
You want about 1/2" of white plastic sticking out of both ends of your PVC
assembly

Soap enough of the cast iron to accept 1/2 of the length of the Fenco plus
about 1" longer for slop.

Install the PVC assembly in the opening in your cast iron stack...now it gets
to be fun slide the lower Fernco over the cast iron and tighten the lower band
only...not bulls ass tight just yet...then holding down on your PVC assembly
raise the upper fernco and tighten (see above bout the bull).

Now we have to line up the Wye with your new stack ...since I am not there I
cannot advise you step by step...but you will need a 3" PVC Street 45 to plumb
the outlet of the Wye.

Once you have the new stack plumb*; it is time to tighten the bottom band.
Now we very slowly allow the upper fernco to accept the weight of your
existing soil stack.

tighten the uppper fernco upper band when the weight has been accepted

double check plumb on the new stack and tighten inner fernco bands.


that is the proper and code accepted way in just about any place in the US
where PVC is accepted as a listed material

Damn I'm tired just typing about it


Vic Plank
Lancaster PA