Is my DWV acceptable & the best option for new 2nd floor master bath?

[tjwor]

I'm adding a bathroom on the 2nd floor of a 1920's house. Full bath and laundry. There is some existing plumbing from a sink, but will be removing it to have all new runs for this project.

Is this my best option for the DWV? The 3" to the basement will be a new hole. Where it is positioned is not the only place I could get it down, but definitely the easiest. I could also find a way to make it work at the 2" to basement area if needed, but there is framing from an old pocket door 6' down inside the wall I would have to find a way to notch.

Does this layout work, and is the best option you see?

 

[tjwor]

I’m going to bump this to the top as I’m hoping to get started on the drain-side stuff this weekend.

 

[Sponsor]

 

[wwhitney]

The connectivity order of fixtures is fine. The pipe sizing is not specified, but the minimum sizes for the bathroom group are:

- 2" for the sink 2 drain starting at the 1.5" vent takeoff.
- 2" for the shower.
- 1.5" for the tub trap arm.
- 2" for the sink 1 drain starting at the 2" vent takeoff.
- 3" starting where the sink 1 drain joins the sink 2, shower, and tub drains, as it is now a wet vent carrying over 4 DFUs

You could split the bathroom group so that sink 2, the tub, and the shower go to the 2" stack to the basement, and just sink 1 and the WC go the 3" stack to the basement.

Cheers, Wayne

 

[Lukewalker64]

Does this layout work, and is the best option you see?

Would also be helpful to know what size your joists are and what direction they run. A 3" pipe is hard to pass through joists because the hole is so big.

 

[tjwor]

The connectivity order of fixtures is fine. The pipe sizing is not specified, but the minimum sizes for the bathroom group are:

- 2" for the sink 2 drain starting at the 1.5" vent takeoff.
- 2" for the shower.
- 1.5" for the tub trap arm.
- 2" for the sink 1 drain starting at the 2" vent takeoff.
- 3" starting where the sink 1 drain joins the sink 2, shower, and tub drains, as it is now a wet vent carrying over 4 DFUs

You could split the bathroom group so that sink 2, the tub, and the shower go to the 2" stack to the basement, and just sink 1 and the WC go the 3" stack to the basement.

Cheers, Wayne

Thanks Wayne! I had tunnel vision from originally trying to get everything into a single stack, I didn't think about splitting the bathroom group when I settled on a separate 2" for the laundry. I think I might switch to going this route since I'm already sending a 2" down in that area.

 

[tjwor]

Does this work for moving to a double vanity and grouping the tub & shower together down the 2" stack? I'm thinking having the washer enter the stack below the shower & tub allows them to vent through that same 2" stack while the washer is vented separately upstream?

Shower & tub will have their appropriate traps upstream.

 

[wwhitney]

Under the UPC, the tub and shower can't join before either one is vented. Traditionally you'd use two stacked san-tees on the stack, or a san-tee with two entries at 90 degrees from each other.

Or you could pull a dry vent off either the tub or shower trap arm with an upright combo, before the two trap arms join, and then that fixture wet vents the other fixture. On the tub the drain after the vent needs to be 2", so you'd use a 2x1-1/2x1-1/2 combo to dry vent it. The 2" san-tee becomes a 2" quarter bend.

Also, again, you can't use a san-tee on its back for venting the washer standpipe, you need to use a combo.

Cheers, Wayne

 

[tjwor]

Thanks again for all the help Wayne, you’re a lifesaver!

I think this setup would check all the boxes?

 

[wwhitney]

I think this setup would check all the boxes?

I think the double fitting with entries across from each other should be a double fixture fitting, rather than a double san-tee, but I'm not 100% clear on the nuances between those two. For any future snaking, a san-tee with side entry is better (as long as you confirm that the side entry has the same radius of curvature as the normal entry), as it avoids the possibility of crossing over from one side entry to the other.

Also, the dry vent only needs to be 1-1/2", unless you need the larger size to satisfy the aggregate vent area through the roof requirement of the UPC.

Cheers, Wayne

 

[MTTim]

Tjwor
not trying to hijack your post but I just joined and saw your recent post. I have new plumbing layout planned for two story house that I would like to get feedback on from all the professionals on the site. I have been reviewing a lot of the forum questions and UPC code rules and think I got most things right - just need to draw up and get on site if okay?
thx
Tim

 

[MTTim]

Hello all,
Here is a sketch of my plan. rough but got most things I think. I have not listed all my fittings or any measurements but I think I got venting basically right between floors knowing there has to be 42" above floor to get above 6" over flood level. Please feel free to correct anything I have done wrong and ask if my drawing is confusing. Looking forward to your comments.

Thx
Tim

 

[GReynolds929]

Tjwor
not trying to hijack your post but I just joined

So don't. Start a new thread like a normal person.

 

[MTTim]

Gee thx GReynolds929 that comment was helpful!

FYI - I did figure out how to start a new thread and I tried to delete above ones b4 they were posted...

 

[GReynolds929]

There's a lot of bots on here lately. Just trying to weed em out. Glad you got it figured out.