If you have original cast iron plumbing, knob and tube wiring, and a 20 year old roof, maybe it would make sense to sell at the peak right now.

There's a lot to have ironed out before you take this plan out of park!  

I would add four more lead paint, asbestos, knob and tube wiring and cast iron drains. 

There's all different references to plumbing and much of that is based on the material it's made out of. ie, PVC, CPVC, copper, cast iron, galvanized (a type of steel pipe), PEX, ABS, Polybutylene and so forth and so on.

Hello BP, I'm currently an investor in the Duluth and Iron Range area (Virginia, Hibbing).

Waste water: Before 1960: Cast iron and occasionally clay (unusual inside a house but found in the ground) and once in a blue moon orangeburg.

It's unfortunate because they are very big and there was a lot of activity, but they need to iron things out.  

Very good question Patrick, what's ironic is that I have a 2 family investment in Bristol Connecticut and in the process of relocating to Columbia, SC next month (warmer climate).

And if someone drops a cast iron skillet, the tile cracks.

Anyway, I called a plumber, and they got the backup cleaned, found the line, popped an "emergency" diagnosis hole in it so they could scope and found the 4" cast iron line rusted through in the bottom which was causing the periodic blockages.