Venting for bathroom group... lost

[danomyte66]

Hey guys,

Trying to do some DYI plumbing for a mother-in-law that includes a bath/shower combo, lav, and toilet. I'm trying to figure out a code-appropriate way to vent. Unfortunately, there's a roof joist above the lav and bath drains, so going straight up is tricky is tricky for the batch/shower combo. For the lav sink, it's not an option at all since the roof joist is the ceiling.

I've read a lot so far but am still really confused by what's allowed with wet-venting. I'm wondering if someone can review the attached diagram and advise if it's something that would pass code. It would be a 3" vent stack with toilet connected (last) and a 3" branch arm that serves as a web-vent for the show/tub and lav.

Thanks!

 

[Terry]

For wet venting to work with that, the lav needs to be 2" for the wet portion of the vertical and it needs a vent above the lav trap arm.
The vent for the toilet does nothing for the shower or lav.

 

[Sponsor]

 

[Reach4]

45 degrees off of vertical is considered vertical for this purpose.

You are allowed to jog horizontally after you are above 6 inches above the rim ("flood level") of the lavatory being vented.

 

[danomyte66]

Thanks! So, the problem there is that I have a roof joist right above the lav... any advice on how to vent? do I need to just run the vent pipe around the joist (in front of)?

 

[Reach4]

Around, not through.

If it comes into the room a bit, could carved-out crown molding hide it?

 

[danomyte66]

Thanks! Great idea, but I think I'm going to actually go through the backside of the wall and up. My mother in law will just need to be okay with the pipe being visible

Otherwise, the tub/shower combo DOES NOT need a vent? I was reading that the wet-vent had to be less than 5' for a tub/shower combo... Sounds like that's not the case?

 

[Stuff]

Since you are early in your build another option is to move or build out the wall a couple of inches to provide room for the vent.

 

[Reach4]

Otherwise, the tub/shower combo DOES NOT need a vent? I was reading that the wet-vent had to be less than 5' for a tub/shower combo... Sounds like that's not the case?

I was not addressing that. Is the tub on the other side of the doorway?

 

[Terry]

If the lav vertical was within 60" and you could trap arm over for the lav then it works for both.

 

[danomyte66]

Since you are early in your build another option is to move or build out the wall a couple of inches to provide room for the vent.

Thanks! I could, but it would be a lot more work and I'm rushin' to get my mother-in-law out of the main house

 

[danomyte66]

I was not addressing that. Is the tub on the other side of the doorway?

it is. That one is a bit easier to vent as there's space between the ceiling and the roof joist.

 

[danomyte66]

If the lav vertical was within 60" and you could trap arm over for the lav then it works for both.

I see... It's 75" from tub drain to the lav. Does that mean I need to vent the tub separately? (I can't revent over horizontally ).

 

[danomyte66]

The tub venting issue set aside, here's what I have as far as materials. Would it be too crazy to ask for a set of eyes here?



Also, I'm noticing there's no donation button for the site. I don't have much to contribute here, so would love to make contribution to the site for all the help...

 

[danomyte66]

Here's a clearer list. I'm thinking I'll take it down to the local hardware store (not big-box).

 

[Reach4]

I think the vents down to the santee and the bath drain can be 1-1/2 inch. You can join vents above the joists, which is probably what you had in mind vs separate roof penetrations.

I think the fitting at the toilet can be a 4x3 closet bend (closet elbow), or that long sweep you propose or even a medium sweep. The 4x3 lets you install an outside or inside 4 inch toilet flange. The toilet can join to the stack with a pair of 45s or a combo or the 3x3x3 santee you specified. I am not sure if the joining of the toilet would be required be above the joining of the bath+lav, giving the toilet a dry vent, or if it matters. To me, logically it should not matter, but logic is not always good in a case like this.

 

[Jeff H Young]

Tub too far away ! I dont see a rafter in the wall I see one next to the wall straight up and out roof looks good to me

 

[danomyte66]

I think the vents down to the santee and the bath drain can be 1-1/2 inch. You can join vents above the joists, which is probably what you had in mind vs separate roof penetrations.

I think the fitting at the toilet can be a 4x3 closet bend (closet elbow), or that long sweep you propose or even a medium sweep. The 4x3 lets you install an outside or inside 4 inch toilet flange. The toilet can join to the stack with a pair of 45s or a combo or the 3x3x3 santee you specified. I am not sure if the joining of the toilet would be required be above the joining of the bath+lav, giving the toilet a dry vent, or if it matters. To me, logically it should not matter, but logic is not always good in a case like this.

Actually, there's no way to loop/revent/join the two vents above the joist as they're roof joists. So, if I was to join them above the joist, they'd be joined above the roof. Or did you have something else in mind?

 

[Reach4]

Actually, there's no way to loop/revent/join the two vents above the joist as they're roof joists. So, if I was to join them above the joist, they'd be joined above the roof. Or did you have something else in mind?

I thought I saw space above the thing you labeled as "Roof Joist". You could also run from the lav, up and then along that labeled joist , and join the tub vent before continuing out of the roof.

 

[Jeff H Young]

Looks more like a cieling Joist but it might not be clear. If thats holding the roof up ?Rafter would be a better term (not picking at you) . Unless you got a whole bunch of pictures we all just guess about this and that and play 100 questions .. Looks like lav is in like a 4 ft high room with doorway a foot away . Dont want to make it easy on us . Good luck!