Next question.
The existing tub had a 1 1/2 drain line all the way to the main drain line of the house (4”).
The video below shows how it was plumbed.
Since the new shower requires a 2” drain, how do/Can I transition to the 1 1/2 inch line?
My thought was to cut the existing 1 1/2” line as close to the 4” line as I can and install a reducing coupler for the last few inches before it goes into the 4” line. But, will that cause too much of a restriction to the flow?
Am I over thinking this or do I need to totally rework where it joins the main line?