For the 3 years we've lived in this house our "second bathroom" has been nothing more than a toilet in the basement. I got the bright idea last weekend to try and build a complete bathroom down there. Well it's turning into a bigger project than I anticipated so I could use some help.

Whoever added the toilet also plumbed a drain for a sink but the plumbing was so impossibly cramped that there wasn't room enough to have a sink there if the bathroom was framed in. I'm going to have to push the plumbing back a few feet to make room. I'd also like to add a shower. On the back side of where I'd like to put the shower I need a drain for the washing machine, I planned to install a wash basin and just have the washer drain into the basin. Since I'll be losing the in floor drain when I move everything around I'd like to install a new one right below or in front of the wash basin.

The layout I'm thinking of is like this:

http://i63.photobucket.com/albums/h1...m/bathroom.jpg

The challenge I'm having is trying to figure out how to vent it. Currently, there are two separate drain systems, pictured below. The old system has the washer on it and the floor drain. The second system was added when they installed the toilet and it ties into the toilet's waste line (3" I believe). Both systems are currently tied together for venting.

http://i63.photobucket.com/albums/h1...m/DSC00618.jpg

http://i63.photobucket.com/albums/h1...m/DSC00615.jpg

So, what here's what I'm trying to do and wondering if it will work:

I was thinking of running the newer drain pipe (2") to the left wall of the bathroom and having it the wash basin and bathroom sink feed into it via a double wye. The pipe would continue to the ceiling where I'd use a 90 to bring it back in line with the current 1.5" vent pipe. Then I'd like to cut the old cast iron pipe, attach ABS and use it for my shower stall and floor drain. The I'm just not sure how or where I should vent that second drain.

Or would I be better off just capping the cast iron system and running the shower, sink, wash basin, and floor drain off a single 2" pipe?

Any help is greatly appreciated. I opened up a real can of worms here!

Ivan

PS The toilet has been moved temporarily in those pics. Just so there's no confusion, the toilet is plumbed back in that corner where you see the TP roll on the wall. The shower will go where the toilet is in these pics.

Hi Ivan,
I've printed out your post and will reply a soon as I get some time to study it.
Unfortunately I have back to back doctors appointments today. I'll try to get on this when I return this afternoon. I just didn't want you to feel ignored. Regards, Tom

Can you draw in the drainage that you wish to install so I can study it? The pictures are a little hard to track. Is the vertical pipe you have labeled "vent stack" really a vent stack,(a dry vent)or is it a stack vent, ( a stack that has fixtures draining into from above?)

Hi Tom,

I'm not an expert on this by any means so forgive my poor terminology. What I have is a stack vent I believe, all the fixtures from upstairs drain into it just above where my picture cut off. It continues up through the roof. The fixtures upstairs, as well as the 2 drains downstairs, are vented into this stack up on the main floor.

I will try to make a rough drawing of the layout I'm thinking of and then post it up here so you can take a look.

Thanks much for the help, I really appreciate it.

Not your fault Ivan,

Vent stacks versus stack vents can be confusing. Especially when you realize that a stack vent morphs into a vent stack just above the highest fixture that drains into it. Cheers, Tom

How do you know if you have a dry vent for a shower stall that is on a slab?

Quote:

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Originally Posted by grandmo1954

How do you know if you have a dry vent for a shower stall that is on a slab?

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There aren't too many dry vents in a basement. All of the vertical pipes are stack vents that are draining something. A exception to this would be if you had a tub or shower that had its own vent. That would be a basement dry vent. Regards, Tom