Master Bath DIY planning phase.

[Danzini]

Currently in the planning phase for a main floor (only 1 level) master bath that will also contain a washer. I did a cut and paste in paint of another persons plan that fits my layout. The attached sketch uses a wet vent setup which I've not done before. I think the washer will cause me not to use this wet vent plan. Also placement of the wet vent may need to be at the end most connection. Its a 9' by 12' room over a 4' crawl space. I've typically vented each component tied to a common vent in the attic. But if this can work then great. Thanks for pointers. Also is there any plumbing design software out there just to sketch up a plan?

 

[wwhitney]

- Change the washer standpipe trap to 2". The vent can be 1-1/2".
- Change the washer drain to 2" and move it to connect to the 3" pipe downstream of the shower. The washer can't participate in a wet vent.
- The sink trap will be above the floor, and it will need a dry vent, which can be 1-1/2" under the IPC.
- The bath and shower trap arms need to hit the 3" horizontal drain/wet vent without turning down at the the end. I.e. they should join in a 3x3x2 wye where is horizontal (both inlet have just 2% slope). That determines the elevation of the bath and shower traps relative to the 3" horizontal drain/wet vent.

Then you will have a compliantly wet vented bathroom.

Cheers, Wayne

 

[Sponsor]

 

[Dielectricunion]

- Change the washer standpipe trap to 2". The vent can be 1-1/2".
- Change the washer drain to 2" and move it to connect to the 3" pipe downstream of the shower. The washer can't participate in a wet vent.
- The sink trap will be above the floor, and it will need a dry vent, which can be 1-1/2" under the IPC.
- The bath and shower trap arms need to hit the 3" horizontal drain/wet vent without turning down at the the end. I.e. they should join in a 3x3x2 wye where is horizontal (both inlet have just 2% slope). That determines the elevation of the bath and shower traps relative to the 3" horizontal drain/wet vent.

Then you will have a compliantly wet vented bathroom.

Cheers, Wayne

I've been a little confused about the wording in IPC section 909.1 in terms of what can tie into the horizontal wet vent. I've been told by several plumbers that fixtures not part of the bathroom group can tie into it if they are separately vented. The section states "...only the fixtures within the bathroom group(s) shall connect to the wet-vented horizontal branch drain. Any additional fixtures shall discharge downstream of the horizontal wet vent."

You may not be using the IPC but wonder how you'd interpret this section

 

[wwhitney]

The section states "...only the fixtures within the bathroom group(s) shall connect to the wet-vented horizontal branch drain. Any additional fixtures shall discharge downstream of the horizontal wet vent."

The laundry is not part of the bathroom group, so it has to discharge downstream of the horizontal wet vent. In your diagram, the horizontal wet vent is the portion of the 3" pipe from where the lavatory joins it down to where the last bathroom fixture joins it.

I've been told by several plumbers that fixtures not part of the bathroom group can tie into it if they are separately vented.

Absent an Indiana amendment to the IPC (you can check at up.codes), that's not true. Non-bathroom fixtures have to tie in downstream of the horizontal wet vent. And they need to be vented separately, since they can't be horizontally wet vented.

Cheers, Wayne

 

[Jeff H Young]

909.1 looks very clear dilectricunion your plumber friends either got it all wrong or like Wayne says your jurisdiction didn't adopt that part of code

 

[Danzini]

- Change the washer standpipe trap to 2". The vent can be 1-1/2".
- Change the washer drain to 2" and move it to connect to the 3" pipe downstream of the shower. The washer can't participate in a wet vent.
- The sink trap will be above the floor, and it will need a dry vent, which can be 1-1/2" under the IPC.
- The bath and shower trap arms need to hit the 3" horizontal drain/wet vent without turning down at the the end. I.e. they should join in a 3x3x2 wye where is horizontal (both inlet have just 2% slope). That determines the elevation of the bath and shower traps relative to the 3" horizontal drain/wet vent.

Then you will have a compliantly wet vented bathroom.

Cheers, Wayne

Thanks Wayne.

Attached are the recommended revisions. I did change the incorrect washer/vent 3' horizontal branch to just a 2" vent, then relocated the washer drain, then corrected the sink vent. My bath and shower will connect at true horizontal with no down turn. I sketch is a rough visual of that now.

 

[wwhitney]

The separate 2" vent you show coming off the 3" line between the WC and the lav is not right. It is not a proper dry vent, because it goes horizontal under the floor. If you changed it so it stayed vertical (at most 45 off plumb) until 6" above the WC flood rim, then it would be a dry vent for the WC.

However, you can also just delete that vent and let the lav wet vent the WC.

Cheers, Wayne

 

[Danzini]

The separate 2" vent you show coming off the 3" line between the WC and the lav is not right. It is not a proper dry vent, because it goes horizontal under the floor. If you changed it so it stayed vertical (at most 45 off plumb) until 6" above the WC flood rim, then it would be a dry vent for the WC.

However, you can also just delete that vent and let the lav wet vent the WC.

Cheers, Wayne

Thanks Wayne. Lav vent sized at 1.5" is enough?.

 

[James Henry]

I don't know how anyone can design a plumbing system without a floor plan. As far as sizing the dry vent for a wet vented bathroom, it needs to be half the size of the largest drain on the system. 3" = 1-1/2".

 

[Danzini]

I don't know how anyone can design a plumbing system without a floor plan. As far as sizing the dry vent for a wet vented bathroom, it needs to be half the size of the largest drain on the system. 3" = 1-1/2".

Tell me about it...I did title this thread as planning phase, but I did provide a sketch(close to a floor plan). My son's just started remodeling/converting his 4th bedroom to a walk in closet and a master bath(10'x12'). I'm just getting better educated before I have to refine specifics.