Hi..

I've had many questions answered searching this site, but I didn't really find an answer to this one. I'm posting some pics to help shed light on the subject - hopefully.

Due to horrible craftsmanship, cosmetic and function issues I decided to remodel my basement bath. I have yet to jack hammer up the concrete so maybe some of my questions will be answered once I get that done today, but I wanted to post to get a consensus.

I am switching the locations of the shower and the toilet. You'll see in the pics there is a 4" vent pipe sticking out of the middle of the floor with the shower vent connected to it near the bottom. This pipe is vertical for approx 45 inches then makes a ninety degree turn and vents into the crawl space under the house. I don't really like this arrangement since the odor ends up under the house, and I need to eliminate the wall that used to hide the vent pipes.

In the current configuration it appears the shower and toilet drains are connected somewhere downstream of the toilet drain. I ran water down the shower drain and did not see it flow through the toilet drain. Based on the location of the main drain from the house, it also appears that the basement drain joins the main pipe to the septic outside the house somewhere.

In order for my plan to work, I need to figure out the venting for this and the vent pipe will need to be horizontal for approx 24" before turning vertical. I don't think a wet vent is a good idea here. So what I am thinking is a T under the slab facing up, then a ninety and a piece of pipe through the foundation to the crawl space, then head up from there and join the master bath shower vent. Will this work? It probably isn't to code, but it won't be inspected and as long as it works I don't care.

Any other ideas?

Thanks!
Michael

Okay.. So a follow up..

I jack hammered the concrete and dug up the hole today. Man am I sore and tired. :)

As I suspected, the shower and toilet drained separately before joining in a wye just under the foundation. The sink also joins the party with another wye just before the main wye. Which means the sink was sharing the shower vent. Interesting configuration.

So, here is my plan: Swap drains! I will eliminate the current vent setup and bore holes through the foundation at two places for the shower and toilet vents where the vents will run horizontally - or nearly so - for a couple of feet. On the other side, they will run vertical before joining together. I have room behind where the drywall will be to give the sink it's own vent out into the crawl space. I included a pic of the sink drain buried in gravel from the hole. BTW, you may be wondering what the painted pipe is. That is a natural gas line that someone ran along the floor because they were lazy. I am going to be fixing that. :) Then I will join all three with the existing master bedroom vent.

Couple of questions with this plan. You can see in the pics where they used a 4" to 2" reducer in the wye that joins the lavatory sink. There is no room to cut that wye off due to the main wye just beyond it. Is it possible to remove that reducer without ruining the wye or am I out of luck there? It would be *really* nice to be able to remove the reducer cause then I wouldn't have to dig a 5 foot hole on the outside of the house in order to access the pipe there.

Also, will having two showers, a toilet and a lavatory sink sharing one 1 1/2" vent overload the vent or will this work?

Opinions? Other options?

Thanks,
Michael