I am working out the details on how to connect my new drain+p trap assembly to the (waste? drain?) pipe in the wall. The new stuff I have is 1 1/4" diameter PVC, and I have an 1/8" turn on the wall pipe (See pic).
From what I've read so far, I need a Fernco fitting to connect these two. The only problem I'm having now is figuring out the diameter of the wall pipe and determining if there is a fernco fitting that will work for me. I measured the outside circumference of the pipe at 5 3/4", which (using math) should come out to be a 1.91" diameter. So.. that's not super helpful. Would this be 2" and my math is failing me? Or is it metric (doubtful, house from the 60s).
Any thoughts on this? Or do I have to take off the current P trap (soldered on) and measure the pipe?