Back to back toilet question

[DRSAP14]

My plumbing contractor wants to jog the toilet drains from the second floor around a kitchen island and into a wall rather than create a fake post with a pipe in it next to the island. Does this look reasonable? It seems kinda serpentine to me but he said with clean outs it should work just fine. Any input would be greatly appreciated. Thank You!

Oh the 1/4 bend elbow just below the double fixture fitting is actually turned 90 degrees into the page. I just cant draw in 3d very well.

 

[stevemachine]

On the vent you need it to be a 3" c.o. And what I'd suggest is replaces

 

[stevemachine]

The 90s with long sweep or a 45 and a fitting 45 glued together. It's definitely not ideal but I think it's acceptable as long as you have the c.o. Even if you didn't have the 3" c.o. On the vent the toilets can serve as a c.o. Depends on what you wanna do.

 

[havasu]

I won't comment on the plumbing itself but wanted to commend you for such a great drawing.

 

[Zanne]

I agree with havasu that it is a good drawing.

The horizontal runs would still have to be 1/4" drop per foot, right?

So it would drop a full inch across the 4' run?

Or am I getting confused?

Edit: this inspired me to look for free software that lets you layout plumbing/piping in 3D/2D. I think I found something but I need to test it out and see how it works.

 

[phishfood]

If it were at all possible, I would rather use 2 sanitary tees stacked on top of each other, or even a double combination wye with 1/8 bends, instead of the double fixture fitting. IPC prohibits back to back toilets on a sanitary cross. Before anyone says it, I know that a double fixture fitting is different
than a sanitary cross, but a snake can still jump right across a double wye. So anytime I can avoid a double fitting, I do.

 

[phishfood]

Oh, and Steve, you really should stop in more often. I've been missing you. In a manly kind of way, of course.

 

[DRSAP14]

Thanks for all the info and suggestions. VERY HELPFUL!!! I did find a fairly simple free 3d drawing tool online called google sketchup with a plumbing plugin from The Engineering Toolbox. I was pressed for time and didn't get it all working so I reverted to an older technology pen and paper... and a scanner. Thanks again one and all.

 

[Zanne]

DRSAP14, I'll have to look at google sketchup and see if it works with my new pen mouse.

I'd love to see any revised sketches you have that implement the suggestions here.

 

[stevemachine]

Oh, and Steve, you really should stop in more often. I've been missing you. In a manly kind of way, of course.

Haha I know I need to, been a while. Miss you in manly way as well