Toilet vent options when stack is 6 feet away

[ralsti]

I'll preface this line of questioning by saying it's likely very stupid since I can't find anyone posting it previously. That's a great confidence builder!

I'm moving my 2nd floor master bathroom toilet to the old shower spot, but to keep the proper drain size, I'm going to plumb back to the original toilet stack and vent that is 6 feet away. I will need to make a horizontal 90 degree turn which I understand needs to happen with a long sweep. I also understand I need 1/4 inch of slope per 1 foot on my toilet drain until it gets to a vent.

The other option is to plumb the drain as above, but if there's concern about the 6 foot run and elbow, I could add a vent closer to the toilet instead of using the existing vent. I could accomplish that by increasing the size of the old shower vent or building a brand new vent and tying into the existing vent in the attic. Assuming we're this far, where would that vent connect into the toilet drain? I can't find a visual anywhere to understand my options, so pictures/diagrams appreciated. May also be helpful to know that the veritical 90 from closet flange will be headed toward the front of the toilet to get back to the old stack.

Any guidance appreciated!

[wjcandee]

Look at the 14th and 15th pages of this: http://www.co.lincoln.or.us/planning...mbingguide.pdf

[hj]

IF you have enough elevation to absorb the 1 1/2" higher toilet drain, then the existing vent is adequate. Installing an additional vent will NOT let you run the drain line with less than 1 1/2" additional slope.

[ralsti]

Thanks for the correction and the link, had reviewed the pdf but was worth a second look.

As hj points out, I think I can make the slope work (joist plus the subfloor will be 10.25", plus flooring TBD), assuming I can find the right parts. I'll need a tight closet bend and a long sweep 90 I believe, but any guidance appreciated.

Here's a picture for grins:

[ralsti]

Hi All,

Thanks again for the advice. I've got one more question -

What's the best way to connect a 3" toilet drain and a 2" shower drain to the stack at the same level? The toilet and shower are both planned to vent at the stack, although the toilet could vent before the stack if that made a wye acceptable on the branch instead of meeting at the stack. It's going to be almost impossible to put one san tee for the shower on top of the san tee for the toilet in the little space I have. I also understand the san tee fitting with a side inlet isn't up to code either.

I've attached an updated picture with a red line showing the proposed shower drain path. Any guidance very much appreciated!

[cacher_chick]

Not sure what code you are referring to, as a sanitary tee with a side inlet is one correct way to plumb it if you are connecting to a vertical stack. If the shower drain is longer than 5 feet from trap to vent, it will need to be re-vented.

[ralsti]

From what I've read, the sanitary tee with side inlet is ok by IPC/SPC, but not UPC. California PC has this clause:

311.0 Prohibited Fittings and Practices
311.1 No double hub fitting, single or double tee branch,
single or double tapped tee branch, side inlet quarter bend,
running thread, band, or saddle shall be used as a drainage
fitting, except that a double hub sanitary tapped tee may
be used on a vertical line as a fixture connection.

I read the exception for a "double hub sanitary tapped tee" as only allowing a sanitary cross, mainly because I can't figure out what a "double hub sanitary tapped tee" really looks like. If you've seen one of these wild animals, link/picture/drawing appreciated.

[cacher_chick]

Sorry, I can't speak for anything that goes on in California.

I would draw it up and bring it to my inspector to get his take on it.