current home is approx. 35-40yrs old slab construction and does not have a cleanout installed within 5' after it leaves the slab.
I dug up the line and see it as hub/spigot cast iron(checked with magnet), but it measures 5" O.D. exactly!??
I want to cut in a wye but todays modern fittings would leave a lip on the I.D. (ie.,4" Wye)
I'm really confused as to:
1. what size line is this? ( I checked a 4" Heavy Wall, but it has a smaller O.D.)
2. How to accomplish what I need to do.