[WackyJackster]

Greetings.
I have just finished demolishing the "Finish" part of my basement. It was always cold plus there was mold behind the walls. Now that everything is gone, my wife and I have decided to add a basement watercloset. How does one locate the drain pipes before tearing up the floor? Does the city have some record of the plumbing layout on file somewhere? Any help would be much appreciate. :)

[speedball1]

Does the city have some record of the plumbing layout on file somewhere? How does one locate the drain pipes before tearing up the floor?

The city doesn't keep records on individual house rough ins, howere, if you know the name of the plumbing company that did the work they may have a copy of the as-built plans. I know my company kept a record of our rough ins in case we were ever called on to remodel a unit.
Why not install a complete bathroom group since you're tearing up the cement anyhow?
Look at the vertical stack vent, now look at the house cleanout. The sewer main should be in direct line between both points. Let me show you a typical basement rough in.
Toilet connects to sewer main or the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes.to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic or if you're reventing back into a fixtures dry vent you must make your connection at least 6 inches over that fixtures flood rim.
Hope this helps, Tom