Avoiding a Horizontal Vent

[hj]

drain

If there are no other complications that we do not know about, then I would run the horizontal connection to the main farther "south" then go "north" under the wall with a vent up and a 45 out to the toilet opening. The shower could be connected into a Y and the same thing done there. OR, you could do the above, but go directly to the toilet opening and then Y off for the shower as described above and use it as the vent. OR, if you have room for that double turn, then a sanitary tee with a 2" side inlet for the shower might also work eliminating the need for a shower vent. There are several other variations which could work, and the "best" choice would depend on which fits the situation the neatest.

 

[quinocampa]

...OR, if you have room for that double turn, then a sanitary tee with a 2" side inlet for the shower might also work eliminating the need for a shower vent. There are several other variations which could work, and the "best" choice would depend on which fits the situation the neatest.

I initially dismissed this, because I'd join the toilet's 3" line beyond the 5' limit from my trap. However, I'd been measuring from the drain center line, instead of from the trap. I gain an additional 6" measuring from the trap, and that gets me right to the toilet line. So, your last idea is the best. I can run straight over without crossing over any joists. Is it better to join the 3" line with a sanitary tee, or a wye? I like the wye because it is a more gradual directional change. Terry said if I were to wet vent in this way, I'd need a 2" vent, which is what I have coming off that low heel at the 180-deg turn. I can return quite a few fittings!

Since I'm wet venting, what is the theoretical risk of flushing the toilet, which is upstream, while the shower is draining? Since the shower drain's 2", seems like there'd be enough space for air to get in there and vent?

 

[Sponsor]

 

[Carradine]

In my view, a horizontal vent cannot be connected to a drain line as per the example to the left, but must be vertical -- any angle 45 and above. As to the connection point on the drain line, it should be downstream as soon as the drain has made it's turn, see drawing to right. This also allows for a clean-out at the end. I'm no plumber, so let the comments fly!

By the way - Thanks to Terry Love for this forum. It is the only source I've found where the information is not less than 3 years old.

 

[Carradine]

Along U-turn of 180 deg as in the diagram would require another clean-out.

 

[NHmaster]

You still have a flat vent there. No vent can run horizontally untill it is 6" above the flood level rim of the highest fixture served. Doesn't matter if it comes off the top of that horizontal or was rolled 45 degrees up, you still need to keep on going up untill your are above the flood rim.

Just deleate the vent. Toilets don't need vents. The are a self siphoning fixture.

 

[Master Brian]

Just deleate the vent. Toilets don't need vents. The are a self siphoning fixture.

Are you being serious?

Not trying to hijack this, but I have a toilet I'm trying to get vented, because I thought they were supposed to be. I installed a wye(?), but have it temporarily capped, until I can get a vent up and out the roof. 1st floor toilet, have to run up closet and then under 2nd floor bathroom floor to get roof access.

I too would have to run a short approx 12-18" semi horizontal run under 1st floor joists to get it up the wall.

If I honestly don't need the vent, then why am I fighting this? I'll just use the wye(?) as a clean out if ever needed....

 

[mule169]

Hey folks, I realize this is a bit of an older thread, but I am sort of in the same situation here. I'm moving a toilet across to the other side of a bathroom during a remodel (about 10' from the main stack where it was previously tyed into the drain stack).

This puts me in the position of trying to vent the toilet through the wall behind it, while draining across the underside of the floor to tye the drain into the stack.

This picture keeps popping up on the interwebs everywhere, and I thought something like this looked promising, except that it looks like this setup has a short horizontal run before it hits the wall, then goes vertical.

Any thoughts? Wondering if I was able to just take that wye straight back to the wall, and omit the horizontal run in this image if that would work? Admittedly that might put the drain quite low into the basement.

Thoughts? I'm still struggling with how I might do this.