Is this 2nd floor bathroom drain layout UPC compliant?

[Ezat]

This site is a goldmine of information. Thanks to all who are participating here. I’ve tried to put what I’ve learned to use in this tub, shower and toilet drain layout for a 2nd floor bathroom remodel. Drawing revisions are painless at this point so I want to get a clear idea of what what will fit where before I start ripping things out. If I’m off track please let me know. I'm also switching out the old ABS for cast iron in hopes of minimizing the sound. Any tips are welcome.

 

[wwhitney]

That would work, although the 2" shower trap arm is limited to 5':

https://up.codes/viewer/los_angeles/ca-plumbing-code-2019/chapter/10/traps-and-interceptors#1002.2

You have various wet venting options to simplify things. For example, if the tub trap arm is really higher than the WC fixture drain, you could vertically wet the WC by putting the tub san-tee over the WC san-tee (low heel 90) and eliminating that parallel vertical segment.

For horizontal wet venting options, a floor plan showing the drain/closet flange locations and the possible locations of the stack below and vent above would be helpful.

Cheers, Wayne

 

[Sponsor]

 

[Jeff H Young]

works fine and complies.

 

[Ezat]

Thanks Wayne and Jeff, appricate your comments. I did some reading. These two images should show more context. I think I'm OK with version A. Version B is easier but I think it violates what I read about wet venting.

 

[wwhitney]

The upper red circle in Version B is fine, it's what I was suggesting, along with keeping the shower as in A.

Under the UPC, fixture drains can not be combined before they are vented, so the lower red circle in B is not OK. But if you had a wall between the shower and WC, and pulled a vertical dry vent off the shower trap arm before it hits the WC, that would make it OK. And the shower would be wet venting the WC.

If you have room vertically for 3 stacked san-tees, you could do the following from top down: 2" vent, 2" (or 2x2x1-1/2) san-tee for the tub, 3x2x2 san-tee for the shower, 3" san-tee for the WC. Making the top two san-tees street would minimize the height. [And if 3x2x2 is not a stock size, you can use a 3x3x2 with a bushing in the top.]

All of this assumes that the shower trap outlet is within 5' of the stack. If it's between 5' and 6', you could use the same connectivity and just enlarge the shower trap and trap arm from 2" to 3" (unusual). If it's over 6', you have to pull a dry vent off between the stack, or else reroute the lav drain so it can wet vent the shower.

Cheers, Wayne

 

[Ezat]

Thanks Wayne. Getting close to final version here. The shower trap outlet is just under 5 feet so I'm OK there. The shower wall is just glass so a vent is not possible.

There is about 26" of verticall height so I can stack all three san tees. The trap for the tub projects through one joist so it's limited to about 9" and has to stay on top. If the stack order is not critical putting the shower on the bottom eliminates collision with the WC pipe.

Would using a long sweep for the WC coupling provide the quietest operation? And last, I'll be using no-hub cast iron for this, do you think it would make much difference sound wise if I packed the joist, soffit and chase areas with mineral wool?

 

[wwhitney]

WC would have to be on the bottom for vertical wet venting.

Cheers, Wayne

 

[hj]

I, personally, sould install a double fixture fitting above the toilet and eliminate ALL the extraneous piping.