Shower and tub horizontal drain

[Cadobe]

Well, two things: the way I drew it looks like it would take a 30 degree elbow (60 was a typo), which doesn't exist. If the geometry works out you could use a 22.5, that's better than a 45. The constraint is getting the up-down the page purple 3" drain close enough to the tub and shower to comply with the 5' trap arm rule, and getting everything connected in the correct order (the first joint has to be lav/WC).

As to 60, for whatever reason its bend radius (in plastic) is tighter than a 45: (3) 60s in succession would be like 2 quarter bends, while (4) 45s in succession would be like 2 long turn 90s. So I would think it makes sense to only use them for horizontal to vertical bends, not horizontal to horizontal or vertical to horizontal. Although I don't think that's actually a code requirement.

Cheers, Wayne

Awesome. Thanks again.

 

[Cadobe]

A 2" trap arm is allowed to fall at most 2" before it's vented, and the shower and tub trap arms are getting vented by their connection to the 3" branch drain.

Not sure if I follow you, are you saying that I cannot run the pipe under the beam?

 

[Sponsor]

 

[Cadobe]

A 2" trap arm is allowed to fall at most 2" before it's vented

I think you are referring to the slope...........2" being the difference between starting and ending point of the trap arm. Am I correct?

 

[wwhitney]

I'm saying that the elevation of the 3" branch drain determines the elevations of the tub and shower traps. The way you drew it is fine.

What is not allowed is to have the trap higher up in your drawing, with the trap arm jogging down to get under the beam. That would be too much fall in the trap arm, it's limited to 2" total fall for a 2" trap.

Based on the drawing, you already knew this, I just wanted to double check.

Cheers, Wayne

 

[wwhitney]

I think you are referring to the slope...........2" being the difference between starting and ending point of the trap arm. Am I correct?

2" is the maximum difference in elevation of the trap arm between the trap outlet elbow and the vent connection. That prevents the trap arm from filling with water and siphoning the 2" trap.

Slope is the rate of change of elevation, and needs to be at least 1/4" per foot. So the two requirement are related. UPC limits a 2" trap arm to 5' in length, even though a trap arm at a perfect 1/4" per foot slope could go 8' before hitting 2" total fall. I guess the UPC wants you to leave a margin for error (the IPC would allow 8'). But if you run your trap arm at 1/2" per foot slope for some reason, the 2" total fall requirement limits you to 4' of length.

Cheers, Wayne

 

[Cadobe]

I'm saying that the elevation of the 3" branch drain determines the elevations of the tub and shower traps. The way you drew it is fine.

What is not allowed is to have the trap higher up in your drawing, with the trap arm jogging down to get under the beam. That would be too much fall in the trap arm, it's limited to 2" total fall for a 2" trap.

Based on the drawing, you already knew this, I just wanted to double check.

Cheers, Wayne

I have updated the image, so you are talking about the red line I presume.

 

[wwhitney]

Yep, the red line is not an allowed trap arm geometry. Unless you add a vent connection before the drop to get under the beam.

Cheers, Wayne

 

[Cadobe]

Thank you Wayne, thank you so much. I am not a plumber just trying to do on my own some plumbing work. Cannot afford $$$$
Appreciate your time on this. I am just a web developer, so anytime if you need anything PM me. Again, thanks a lot.

 

[wwhitney]

Then I suggest you get our feedback before/after installation, by posting either a scaled 3D model of the planned DWV including all the fitting and sizing details (if that's easy for you to do on the computer), or else a photo of your work, or a dry-fit, or a mockup.

Cheers, Wayne

 

[Cadobe]

Then I suggest you get our feedback before/after installation, by posting either a scaled 3D model of the planned DWV including all the fitting and sizing details (if that's easy for you to do on the computer), or else a photo of your work, or a dry-fit, or a mockup.

Cheers, Wayne

Sure I will.

 

[Jeff H Young]

So, I'm not sure which way the joists run, but a standard wet vent solution could look something like the drawing below. Purple is 3", green is 2". If you need to tie in at the end of the red 3" line you drew, you could of course jog back to the location. The 3" purple line running up and down the page needs to be located so that the tub and shower trap arms both comply with the 5' limit on a 2" trap arm. And the WC needs to be (wet) vented by the lav within 6' of the closet flange, so you might have to route the lav drain to hit the 3" purple line closer to the WC to comply with that.

Note that the unamended UPC require that the WC be last on the wet vent, but my understanding is that Washington State has deleted that requirement.

Cheers, Wayne

View attachment 76601

Pretty much the same thing I was thinking needing 2 trap arms, moving the main over I didn't consider as the note sounded like it might be imbedded in a stem wall or concrete. so I don't know if moving it works but your idea would be great .
Also Maybe Washington is Lax on code but OP you going to need to consider cleanout a full size one wither 5 foot of end of line it will get you reamed by inspector at least down here

 

[Cadobe]

Pretty much the same thing I was thinking needing 2 trap arms, moving the main over I didn't consider as the note sounded like it might be imbedded in a stem wall or concrete. so I don't know if moving it works but your idea would be great .
Also Maybe Washington is Lax on code but OP you going to need to consider cleanout a full size one wither 5 foot of end of line it will get you reamed by inspector at least down here

Indeed I will put cleanouts on each end -> toilet, shower and tub

 

[wwhitney]

How do you plan to do shower/tub cleanouts? Someone else can correct me if I'm wrong, but I think those are unusual.

Cheers, Wayne

 

[Cadobe]

How do you plan to do shower/tub cleanouts? Someone else can correct me if I'm wrong, but I think those are unusual.

Cheers, Wayne

I though that is required for each end of drain line. I was thinking on driving the tub/shower 2" into 2" wye that one end is the flow and other end would be the cleanout. However for toilet end I need to have a cleanout, right?

 

[wwhitney]

I'm not super familiar with the cleanout rules, but here's the section that governs cleanout location:

https://up.codes/viewer/washington/upc-2018/chapter/7/sanitary-drainage#707.4

It says cleanouts are allowed to be omitted on a horizontal drain line less than 5' in length for other than sinks and urinals. So that would apply to the shower and tub trap arms, assuming that you stick with the normal 2" size and therefore keep them under 5'.

But yes, you need one for the toilet end.

Cheers, Wayne

 

[Cadobe]

I'm not super familiar with the cleanout rules, but here's the section that governs cleanout location:

https://up.codes/viewer/washington/upc-2018/chapter/7/sanitary-drainage#707.4

It says cleanouts are allowed to be omitted on a horizontal drain line less than 5' in length for other than sinks and urinals. So that would apply to the shower and tub trap arms, assuming that you stick with the normal 2" size and therefore keep them under 5'.

But yes, you need one for the toilet end.

Cheers, Wayne

Thanks Wayne