Toilet drain/vent question

[TedO]

As this is my first post, let me first say that over the years I've found plenty of useful, candid advise on this forum - thanks all.

I need to replace a section of 4'' CI waste stack and lead closet bend in an "older" house, and hope that someone will be able to tell me if I'm on the right track. A sophisticated CAD drawing is attached, but here are the basic questions that I have (doing my level best to use the correct terminology).

1. The project is involves a first floor bathroom. The current vent for the toilet is original and originates in the lead closet bend (see drawing). So, since I'm pretty sure I can't replicated the existing configuration, I'll need to put the vent downstream from the toilet. My plan is to tie into the existing 2'' galvanized steel vent, which seems to be in good condition (again - see drawing). If that's fine, should I use a 4''x2'' sanitary Tee to begin the connection to the vent?

2. If #1(above) is OK, then to do it, I'll need to orient the waste pipe parallel to the plumbing wall in order to connect to the vent. To do that, I think I would need to have two 1/4 bends in the horizontal pipe to the stack (the toilet flange is about 3'' from the stack). I was planning to use 3'' pvc for the toilet drain pipe. Does that all sound OK?

3. There's a 45 degree jog in the stack just behind the first floor toilet (once again - see drawing). It would be easiest to tie into the stack in the section that is 45 degrees to vertical, and I'm guessing that - since it would be closer to the ground - there would be slightly less noise than if I were to connect above the second 1/4 bend. Is there a disadvantage/problem with having a "proflex" connection on other than vertical pipes?

4. Other obvious problems/gottchas? I feel pretty confident in the actual work, if the plan is sound. But if there are many other considerations that I am overlooking, please let me know!

A note on the drawing: we do have other fixtures, other than a toilet. The plumbing to them was omitted to simplify the drawing. the first Floor shower and lav would connect just below the toilet.

Thanks in advance for your response.

 

[TedO]

Thanks bnitsuj007, glad to be of service. Anyone else able to comment?

 

[Sponsor]

 

[Redwood]

In your sophisticated CAD drawing it looks like you are attempting to vent with a heel 90...

Thats a no go....

 

[TedO]

Thanks for the reply, Redwood. Would this be an acceptable unit:

http://images.lowes.com/product/converted/611942/611942035694lg.jpg

 

[DavidTu]

yes that is the correct vent. 3"X2". I think Redwood was confused by the order of your drawings...the one on the left is the NEW proposal. The old one used the lo heel in the wrong orientation.

 

[Redwood]

Oops i did mess up on the new and old order...

That is the correct fitting to use.

 

[TedO]

My fault, really. "After" should be on the right. I figured that out after I was done, but it was too late.

So, just to be clear, with the 2'' pointing up, I can definitely use:

http://images.lowes.com/product/converted/611942/611942035694lg.jpg

But what about a sanitary Tee: http://images.lowes.com/product/converted/611942/611942034734lg.jpg (it would easier)

Also, the other question main was about having the two horizontal 45 degree bends in the 3'' pipe so that I can orient it parallel to the wall. Is that an issue for any reason?

Thanks in advance.

 

[DavidTu]

You cannot use a sani-tee on its back for venting. They want a fitting designed for vertical to horizontal transition for drainage, in case the pipe backs up they want the thing to drain out cleanly. I think the pros will say ok to 2 x 45's. Note that in your original post you wrote 1/4 bends (90-deg) instead of 1/8 bend.

 

[Kreemoweet]

"You cannot use a sani-tee on its back for venting." Well, this may be true in some jurisdictions, but it is a common
practice in many parts, possibly the majority, of the U.S. Even in Seattle/King County, which is under the more restrictive Uniform Plumbing Code,
it is permitted in many situations.

 

[Terry]

Used to be accepted years ago in King County. Not now.

 

[TedO]

OK - sounds like a "no" on the sanitary Tee. Two 45's would be acceptable, though?

Also still wondering about the two 45 degree bends in the horizontal 3'' pipe. It seems like that might not be ideal, but I can't see another way to do it.

Also - if anything else in the plan looks off, please let me know. Thanks again.