Under Slab Plumbing Redo

[DIYPlumberGuy]

We had a slab that failed and are in the process of getting a new one. As a part of this, I want to plumb in drain plumbing for an eventual basement bathroom plus redo everything else. I've done a ton of reading and have a general plan, but I thought I'd run it by the forum to get everyone's thoughts. I've already pulled a permit on this and want to do everything by the book.

Here's the basic layout I'm thinking about. I plan to run a new 3" stack from the bathroom, through the wall behind the main level toilet where the existing stack runs, and up to the roof. I additionally have a 1.5" stack above the kitchen (where there's a sink, plus a dishwasher that drains into its disposal).

I'm in MN and once everything is done I should have the following DFUs: toilet x2 (6), tub x2 (4), bathroom sink x 2 (2), kitchen sink (2), dishwasher (2), washer and sink (2+2), plus a small drain for a condensing boiler and a steam generator which puts me at a total of 20-22 (assuming the last two are 1 each?).

I plan to do the toilet 12.5" from the planned wall, plus make sure it's got 15" on each side. Shower I plan to get centered in that eventual framed out enclosure and the tub will be dependent on what style we land on. I plan to install a cleanout near the new basement toilet and have one where the vent goes up below the kitchen. Everything besides toilets will have a trap.

I'm looking for suggestions on how to improve this layout, and I'm also wondering if you think I'll need to run a 2" vent above the kitchen or if the existing 1.5" should suffice. Thanks in advance.

 

[James Henry]

Repost your floor plan without the drain lines drawn in and put a small circle to indicate where the vents are and whether that toilet vent isn't really a drain stack , also put an arrow where the sewer exits. You also have not shown the kitchen in the drawing. their are people on here who can help you get the ball rolling on your design but as it stands now it doesn't look very code compliant or have the proper venting. Is that big circle in the laundry room a floor drain?

 

[Sponsor]

 

[DIYPlumberGuy]

Thanks, James. I was trying to say too much with that first picture, but hopefully this gives a better idea. I went and looked at it a bit more and I think I see what you may have been getting at. It seems that the (to be decommissioned) laundry drain is dry vented over to the area next to the waste stack. I hope this makes more sense.

And yes, that circle to the right was a floor drain.

 

[James Henry]

Off the top of my head. Not sure what your plans are for the existing plumbing so I ignored it.

 

[DIYPlumberGuy]

Thanks, James. Just to clarify, is red a vent, cleanout, or both? And can you clarify the "wet vent" label?

 

[Breplum]

I recommend you hire a licensed plumber or contractor to create a layout/plan that will meet code and make good sense.
It would be money well spent.

 

[James Henry]

I recommend you hire a licensed plumber or contractor to create a layout/plan that will meet code and make good sense.
It would be money well spent.

Are you saying my crude finger painting doesn't make sense? C'mon man!

 

[James Henry]

Thanks, James. Just to clarify, is red a vent, cleanout, or both? And can you clarify the "wet vent" label?

The red circles are vents and the blue are p-traps.

 

[DIYPlumberGuy]

Thanks all. I've got a plumber lined up to do the bulk of the work.

The one remaining question I have is with regards to my main stack. Currently it goes straight down from just behind the existing main level toilet, and then runs underground to the street. If I wanted to move this, what options might I have? If I secured it above with a riser clamp or two could I conceivably cut it near the joists, then angle it with PVC over to the wall and down? I'd like to buy that space back if possible, but the plumbers I've had out generally scoff at the job. Do I have any options there?