Moving Toilet, need advice on venting

[Michael9898]

Hello,
I'm starting a remodel job in the master bath. Wife wants to move the toilet. I've enclosed diagrams below and would like advice on how to proceed. Master bath is located on second floor, branch is 3in line and in a horizontal configuration.

1. In diagram 1, vent is located in wall and moving toilet would put it at 16 inches from wall.
In diagram 2, would this work? also looking for what fitting is appropriate. Shower drain is a currently a wet vent, would I need to build shower vent?

Thanks
Michael

 

[wwhitney]

I think we need a bit more information about the existing configuration, outside the boundaries of the photo. Is the shower the only fixture coming into the wye on the 2" branch? Where are the vents?

For the shower drain to be wet vented, it would need to join a dry vented fixture (such as the lav), before it joins the WC (at the wye). Then it could go on to wet vent the WC. In which case moving the WC wouldn't require any changes in venting.

But if there's no vent for the WC and no vent for the shower upstream of that wye, then currently neither fixture is vented. A vent connection is required before (dry vent) or as (wet vent) a fixture drain joins another drain.

Cheers, Wayne

 

[Sponsor]

 

[Michael9898]

I think we need a bit more information about the existing configuration, outside the boundaries of the photo. Is the shower the only fixture coming into the wye on the 2" branch? Where are the vents?

For the shower drain to be wet vented, it would need to join a dry vented fixture (such as the lav), before it joins the WC (at the wye). Then it could go on to wet vent the WC. In which case moving the WC wouldn't require any changes in venting.

But if there's no vent for the WC and no vent for the shower upstream of that wye, then currently neither fixture is vented. A vent connection is required before (dry vent) or as (wet vent) a fixture drain joins another drain.

Cheers, Wayne

Hi Wayne,
Yes I just checked, the lav is connected to the shower drain before the wye and is dry vented. As for the new connection, would I be able to use a 3inch Sani-tee for the WC?

 

[wwhitney]

OK, so if you confirm the lav is properly vented, it is wet venting the shower and the WC. Good.

To move the WC, assuming the 3" line continues down off the bottom of the picture under the subfloor, just move the wye farther down the page, but otherwise keep the same configuration. You can extend the 2" line down the joist bay.

You can't use a san-tee on its back for drainage. It's best avoided for anything except connecting 3 vents, although the IPC allows it for a vertical vent takeoff on a horizontal trap arm.

Cheers, Wayne

 

[Michael9898]

Ok I didn't think I could use a san-tee for this, but here is the problem that I'm trying to avoid. Here is a pic of the branch, the vent is in the wall separating the bath from the master bedroom. Trying to avoid ripping out subfloor in the master bedroom but I'm out of space to just move the wye down and keep the original configuration without running into the the vent line. Maybe a 3in long sweep connecting the WC or is that also not allowed?

 

[wwhitney]

Are you sure the line with the blue arrow in the last picture is a vent? As a san-tee on its back, it had best be, rather than a drain. But if your lav is dry vented, and the lav drain hits the shower to wet vent it, and they jointly hit the WC to wet vent that, then the extra vent takeoff isn't required. On the other hand it doesn't hurt.

Anyway, I see now that in the first picture there's a wall at the bottom of the picture; the new WC location is 16" off that wall, so the WC will face to the left? Then you have room for the wye, a 3" street quarter bend has a run of 4-9/16" with the street end downstream, and the run of a 3x3x2 wye is 5". Add 1-1/2" for the depth of the 3" hub on the outlet of the wye, and the edge of that wye will be about 11" from the center-line of the closet flange. The run on the san-tee on its back for the existing vent takeoff under the wall is maybe 3-1/2", so while the hub of that san-tee may stick out past the drywall, it would only be about 1" past the drywall.

Cheers, Wayne

 

[Michael9898]

Ok I'll get the parts and report back. thanks again for the help.

 

[Michael9898]

would this work?

 

[wwhitney]

To recapitulate, in the picture above, the quarter bend is a closet bend for a WC, the wye 2" branch coming in has the dry vented lav and the wet vented shower, and the combined drainage is leaving the wye outlet. If so, yes, that works for wet venting the WC.

Cheers, Wayne

 

[John Gayewski]

In your sketch you have an abandoned section of pipe capped off. Your better off extending that up through the floor, inside of that near, wall and making it an accessible cleanout.