Basement Bathroom

We have a small house with just one bathroom. I am planning on finishing the basement and would like to put in a bathroom. There is currently no rough-in for the toilet, shower, and sink. To do the rough-in I need to tie into the existing drainage. This is pretty easy since I am putting the new bathroom directly under the upstairs bathroom. However, when the existing drain goes into the concrete, I don't know which direction it goes in. How can I figure out where the drain is going? My house is really old (1952) and I do not know where I can get the plans. I called our county government with no luck. I am thinking of score and breaking up the concrete right where the drain goes into the floor and then go from there. Any other ideas would be great help.

 

I was in a similar situation a few months ago, except my house was built around 1955. I had a plumber come in and do the drain and vent work, but here are a few of my thoughts from the experience.

Cleanout - before the drain pipe (likely cast iron) goes into the concrete there will likely be a rectangular plate or similar held on with a couple of bolts. You could remove this and send a straightened out coat hanger through it to get a sense of the direction it goes. Before doing this, I would inspect the condition of the bolts to make sure that you can close the cleanout back up when you are done. I also had a cleanout in the floor just before the pipe exited the building, but that looks like it is from work that one of the previous owners did.

Drain - FWIW, it will likely drain toward the street where the sewer system is in most cases. If you are on a corner lot like I am then it will likely drain to the nearest street.

Venting - you will need a vent for things to drain and a place to tie the vent into the existing stack, or be prepared to have to put an additional stack in. This may be a larger issue than roughing in the drains for the sink, shower, and toilet.

Supply piping - I used copper because, well, I'm old fashioned and my existing plumbing is all copper. Sweating copper is no big deal (IMHO) and I did most of it myself. Keep in mind that it is wise to keep supply piping on interior walls and avoid exterior walls if you are in a cold climate.


I found the plumbers I worked with very helpful (plumbers, not handymen or jack of all trades who can do some plumbing). I presented what I _wanted_ to do, they looked at things, poked about, and told me what I _could_ do and then quoted it and did it for a reasonable price. I suspect most are like that, or I got really lucky.

Apologies for the length and the rambling, but hope it is helpful.