Installing the drain reroute was mentally taxing but my head will thank me later (the old drain's run was a frequent headache). I dry-fitted as much as possible prior to cutting the old line but many of the work-arounds could only be calculated with the new drain in place. The downtime for the home's water systems was 1 day (off in the morning, on by 8PM). If there are shortcuts to calculating the spatially complex intersections of angles and length as the main drain slopes gradually down and existing tributaries are tied into it, I did not find them. The surest guarantee of a good intersection is a lot of initial distance between the pipes to be joined. Of course, the reality of existing lines, walls, ducts, and slope seem to rear their heads just as a simple run is contemplated. I can't imagine doing the job working with the original, cast-iron pipes; heavy and inflexible. Fortunately, PVC is light and easy to cut. A bit late in the game I also discovered a limited assortment of flexible, rubber couplings. These provide some "give" within the structure to help with alignment at the intersections. My next drain refit project will include more flexible couplings. When it comes to fit-forgiveness and speed of installation, they are well worth the slight increase in cost over their rigid, PVC counterparts. If you look closely at the photo below you will see two, difficult to source 4"x4", Flexible "T" Couplings joining the PVC to the cast iron. The black plastic sheeting was on the "recommendation" list from our home inspector and will function to keep moisture from the fill-soil out of the basement. It should also reduce dust and make potential leaks (none yet) highly visible.

The high and low of a basement drain:


Tip: When gluing long sections of large-diameter pipe into place it can be very difficult to squeeze the sections together for a "bottomed-out"/"flush" fit. The 4" pipe is nearly impossible to grip and pull by hand with enough force to bring the pieces fully together. Instead, take a length of the banding wire (the metal band/strap used to hang the pipe from the overhead joists) and wrap it once around the length of pipe an arms-length away from the joint. Secure the loop back on itself with a nut and bolt -the fit need not be tight. Next, glue and fit the pieces together. Now, pull the loose end of the banding wire loop toward the joint. The loop will hold-fast and the line will give you a handle and enough leverage to pull the pipe fully into the joint. If fitting two pipes together in a straight run, use a separate loop and line on each and pull together like a butterfly press.

Tip: I rented a chain-break pipe cutter which was essential for cutting the old, cast iron pipe quickly and cleanly. Art Pancakes Rent-All of Nashville charged $20 for the day and there is no substitute for the tool or for their friendly service.