Hi Everyone, I have decided to DIY a basement bathroom/plumbing project. I have been researching for a past few days, and I think I have figured out how everything should be setup. I have mocked-up my design in Sketchup, but would really like it if someone could check it out and let me know what I did wrong.

Some Notes:
-Main stack has a toilet,sink and shower upstream on the main floor.
-Clean-outs and expansion joints will be installed at every vertical stack
-There is a secondary 1-1/2" stack that vents out of the attic for the main-floor kitchen sink. (Not shown)
-Shower vent ties into an existing vent that leads to the main stack.
-I have not busted up the floor yet, so I am not 100% sure how to tie in this new line. Doing that tomorrow.
-A dummy wall will be built in-front of the insulated exterior wall to prevent the pipes from freezing.

A few things that I was wondering about:
1. Do you need to have a clean-out for a dedicated vent stack? (the one off of the shower) If not, I will route it better.
2. Do I even need a vent stack for the shower? Wet venting is permitted in Manitoba, however I am not sure if the vent for the sink is close enough.
3. Do clean-outs need to be fully exposed, or can I have them buried enough so that you can just remove the cap?
4. Does it make sense to run 4" pipe to the toilet, or is 3" good enough?
5. Does the toilet have to be downstream of the sink and shower. I am a bit confused by this.
6. I have two options for the sink vent. Either I can tie it into the secondary roof stack as a wet vent, or I can cut up the wall and tee in a dry vent above the kitchen sink. I am not sure if this existing 1-1/2" pipe is suitable to wet vent a toilet, 2 sinks and a washing machine. I doubt it.
7. I got the impression from this file that I had to use double 45Deg fittings instead of a sweeping elbow when transitioning from horizontal to vertical. (See page 7 & 9) Whats the idea behind this?

Files & Pics

Thanks in advance for all the help.

 

Overall, looks good!

To answer your questions and provide a few comments:

I highly doubt it. You should be able to use the shower drain to snake if needed, and it's not a stack, so shouldn't need its own clean out.

I don't see any reason for a second vent for the shower. Usually one fixture group (the bathroom) can all share the sink's vent.

They can be covered with a door or one of those spring loaded wall plates. Or they can be at the wall-level. Basically, as long as you can easily remove the cap and snake from there, you're good. I don't see any reason for any clean outs other than at the base of the stack

3" is just fine. No need to hassle with the larger pipes.

Nope

You need a 2" pipe to vent the toilet. I don't quite understand the wet vent question. It really should go up above the flood rim of any other fixture, then back-vent (connect) into the vent at that point. I don't think you can vent the sink into another pipe creating a wet vent.

That's the way I read it too. Most plumbing codes require either a long-sweep ell, OR double 45's. It seems like they want the double 45's. I believe the bend ends up being about the same.

* I would use 3x3x2 wyes (instead of 3x3x3 and reducers). Cheaper and easier, though nothing wrong with the way you have it drawn.

* I was going to say that you typically don't need expansion joints in most residential work, but it looks like your local code says you need them... so you do need them!

* At the sink, you probably don't need a clean out. The tee acts as a clean out as long as it's plumbed with slip fittings. If you need a clean out, I would put a second tee with a plug in it under the sink and use that as a clean out. With the wye as you have it, you'll need to really hack up the bottom base of the cabinet to get to it.


Good luck with the cement!