Connecting to a sewer hub in a basement
This is somewhat similar to my last question, but it's different enough that I am going to ask about it specifically.
I am trying to add a second bathroom to a house that was built in 1940. I have most of the waste/vent/drain plumbing figured out, except where I will connect to the sewer hub in the basement floor.
I have done something like this previously and I purchased a rubber donut that snuggly fit into the sewer hub. This allowed me to connect a 3-inch PVC pipe into the sewer.
In this case, I bought a 4-inch donut for a 3-inch PVC pipe (i.e. it is a reducing donut hub)... but this is too big for my sewer hub. I then bought a 3-inch donut hub for a 3-inch PVC pipe... and this is too small.
Are there other sizes available? Where might I find one for purchase? Should I be solving this problem a different way?
I'll try and post a photo soon.
Thanks,
Tim