Cast Iron Wye to ABS Repair- Will this work?

[FixerLady]

Hello all, I've been pouring over the forums here and want to first thank everyone for contributing to these forums. I'm in the middle of a bathroom remodel have moved the shower and toilet to new locations. This is my home and I'm doing the work so before I close things up I wanted to post some pictures here to verify that I'm on the right path.

1. The main soil pipe under the house is cast iron, I've tied into it with a new 3" ABS wye and 45 using Fernco P3000-33 couplers. My question here is, are these the right couplings? I've cleaned the cast iron with a wire cup brush and they slid right on with no problems. I can twist the wye around fairly easily and before I torque down the clamps I wanted to verify, should the rubber be tighter around the cast iron (before torquing the clamps)?

2. This is a little trickier. To tie in the shower and get the right slope, I've had to cut the old cast iron wye below the hub. *I realize this was a bad decision but there isn't much room to install a new line without removing all other cast iron that's touching it. I've installed a doughnut inside the wye, it's quite tight and with the 2" ABS it's not coming out easily. For added peace of mind I also want to install a Ferco 3"x2" coupling on top of all that. What do you think of all this?

 

[wwhitney]

I've only worked with no hub cast iron in new work, not old hubbed cast iron, but here is my understanding:

(1) P3000-33 is the correct shielded coupling for 3" cast iron to 3" schedule 40 plastic. Note that the two sides of the rubber are slightly different, they are marked on the inside either CI or PL. As long as you have the CI side on the cast iron, the pipes coaxial and fully seated in the coupling, and have torqued it with the proper torque wrench, it should work well.

(2) Seems like a better solution would be to remove the cast iron 90 back to the hub on the wye, if you can do so without damaging the cast iron wye. Then you can get the proper size Fernco donut to connect an ABS street 90 into the hub on the cast iron wye.

Cheers, Wayne