ABS < -> Copper fittings are 7.5″ long. The drop from the floor to the existing copper elbow is only 6″ so, I can’t use an adapter on the vertical run. Suspecting this in advance, I purchased everything I need to replace the DWV piping all the way back to the “closet” (a plumbing euphemism for toilet, apparently): adapter, straight pipe, elbow, closet flange, and a new wax fitting (with bolts).

So now I have to remove the upstairs toilet, replace all of the DWV plumbing, and re-install the toilet. I’ll probably have other parts to replace in the process; the water inlet piping, for example, is old and will probably need replacing.

I’m really hoping that it stops there. Minor leaks like this too often mushroom into massive renovations, and I already need to re-drywall the downstairs bathroom when this is all done…