Buried Fernco/Mission coupling - use metal banded or all rubber?

[Bcarlson78248]

I am remodeling a basement bathroom and have excavated around the existing 4" XH cast iron drain pipe. I will be cutting this pipe off and then connecting it to new 4" PVC drain pipe that will serve the relocated fixtures. I need to comply with the 2009 Virginia plumbing code, which is based on the 2009 IPC.

I thought that under a slab the drain pipe was supported by the fill dirt, so you used an all-rubber Fernco coupling to tie PVC to CI. In fact, I thought I remembered reading somewhere that the metal banded couplings were not recommended for under slab use. However, in another forum question Terry said he recommended the banded coupling to stabilize the pipe for a buried installation.

What is the right type of Fernco/Mission coupling to use for a buried connection from 4" PVC to 4" CI XH?

Thanks,

Bruce

 

[hj]

Teh all rubber "Fernco" is ONLY permitted underground "outside" the building. The banded ones are used indoors, and if they could not be used underground there is no way we could install cast iron drain systems.

 

[Sponsor]

 

[Terry]

As a plumber, I don't use rubber couplings.
I do use the banded, or shielded couplings with the metal wrap. It's the only way to pass an inspection.

 

[Dj2]

The banded connector keeps the two pipes aligned.