Shower venting -- sanitary tee laid on it's back

[Geekything]

Hi.

I know a sanitary tee can be laid on its back with the "tee" pointing vertically. But can it be laid on its back with the tee pointing out horizontally -- of course the vent pipe would be 1/4" sloped.

This would avoid a great deal of bends in the vent for a shower remodal. Which is the next question: is the degree limit per bend (225-degrees?) or cumulatively?

Thanks so much.

P.S: For what it's worth, this is 2" drain and 1.5" vent. I'm in Ontario, Canada.

Edit: sorry, this may have been more appropriate for the plumbing forum.

 

[Terry]

A tee can not be used on the horizontal to vent on the horizontal.
You would use a wye or combo fitting on the horizontal.
When I used to do that, I would raise the wye portion above the flow line of the pipe before I started my grade.
On a wet vent, I use a wye on the horizontal if it's washed by a lav.

 

[Sponsor]

 

[Geekything]

Okay, I rethought what I was doing and believe I found a cleaner solution (but not a cleaner job site ).

2" shower drain goes straight into the end of a 2" drain. The 2" drain has a 2"*2"*1.5" tee where the dry vent will come off of. You can't see the horizontal part of the vent because it was ripped out.

There's then a 2" to 3" coupling to the main drain line. Tied into this is a 3" drain for a toilet with a 3*3*3" wye.

My question now is....does the toilet really need a separate vent? Can it rely on the vent further up the drain? All fixtures are within 6-feet of each other. I'm in Ontario, Canada code-wise.

Thanks in advance!

 

[Terry]

The shower is not vented.

Venting comes off the top of the trap arm, not two fittings below.

 

[Geekything]

Okay, I can put a tee on the trap arm rolled 45-degrees to avoid it caring the waste and then a 90 to align it with the existing vent.

At that point, should that be sufficient to vent the toilet just downstream (couple of feet) on the 3" part of the drain?

Thanks, Terry for your patience and support!

 

[Cacher_Chick]

In the U.S., the vent take-off is done with a wye, which has be rolled up at least 45 degrees, opposing the direction of the drains flow. The entire vent must be vertical, which means no section can fall below 45 degrees.

Alternatively, the vent can take off from the top of a sanitary tee, if the trap arm is connecting to section of drain on the vertical.

 

[Geekything]

Thanks, Cacher_chick.

I seem to recall that [after the wye] I'm then allowed to turn up to 225-degrees to get to my location....I'd need a 135-degrese turn to "double-back" on myself post-wye.

Unfortunately, this is a very constrained space and I'm limited in my design If it were wide open, it'd be easy -- but I guess this is where the skill of a licensed plumber comes into play

 

[Cacher_Chick]

There can be turns in the drain, but every inch of the vent must rise vertically until it meets the minimum height. Sometimes the drain will need to be routed to an entirely different location to make the vent work.

 

[Geekything]

The only way I can get the 6" height is if I move the P-trap into the area that says '1.5" vent'. So, the shower drain would be extended to that area, then p-trap in the void and a 6" vertical rise before the vent goes horizontal.

Kosher?

Edit: I may go back to using 1.5" pipe given the space constraints. It's legal here and the shower would be low-flow anyways. I just wanted to do the "right job" not the easiest job

 

[Cacher_Chick]

We must be speaking different in tounges, as we are not allowed to run a vent on the horizontal until it is a minimum of 6" above the flood rim of the highest connected fixture or 44" above the floor, WHICHEVER IS HIGHER.

This is mandated to prevent solids from ever restricting a horizontal dry vent in the case of a backup.

 

[Cacher_Chick]

This is why we always run a shower drain under a location where there there are walls above, because the vent must rise vertically within the wall cavity at least 44" before turning if it needs to in order to make it through the roof.

 

[Geekything]

Okay, understood. Thanks.

I'm going to work under the assumption the previous plumbing wasn't to code/inspected as it did what I alluded to.

Anyhoo, the simplest solution is likely the best -- I'll flip the shower pan around so that the drain is at the wall with vent(s). I have enough room to build a small bulkhead there too. Luckily it's a 60" wide shower pan and I have this option.

If you're doing this between joists/studs, how on earth do you get a drain, tee for the vent and return for the waste all within there?!

Thanks for your help.

 

[Cacher_Chick]

In most cases the shower drain is centered in the shower pan. A 2" trap arm at 1/4" slope allows a vent take-off to be placed anywhere within the first 8 feet of pipe. It can turn left or right (but not down) before the vent. The total change of direction cannot exceed 135 degrees without adding an accessable cleanout.

 

[Geekything]

This is what I ended up doing....I moved everything to the opposing wall where I have access to a dry vent. Unfortunately, the drain in this bathroom isn't a stack -- drain and venting are split. I'll replace my 90s with 45s when I next go to the big orange store.

One of my original questions was....is a dry vented shower upstream (I gather that's important ) of a toilet able to act as a wet vent for the toilet?
Thanks!

 

[Cacher_Chick]

The WC can be wet vented by the shower vent. Minimum pipe size for a wet vent is 2".

 

[Geekything]

The 3" toilet drain is reduced to 2" drain for the shower and the shower is vented by a 1.5" "dry vent" going straight up through the roof by itself (i.e. dedicated).

When you say the wet vent must be 2" -- that's the minimum drain size before it gets vented? Can I keep my 1.5" dry vent? I've read some training material for Ontario code that seems to illustrate 1.5" dry vent pipe is okay.

Thanks!

---
EDIT:

After reading some more it sounds like if the wet vent portion is 2" (like mine) I am allowed a continuos vent size of 1.5" as long as my trap arm is limited to 1.5m (~5ft). And the length of my continuous vent impacts the number of fixture units I'm allowed to service via the wet vent.

It's also illustrated in this that as long as I keep my units in check, I can do what I'm proposing.

 

[Cacher_Chick]

Right, the actual wet portion must be 2". Your code may allow the 1-1/2 vent stack for a bath. Here in the U.S, there are different requirements depending on which plumbing code is used an a particular state as there is no nationwide code.

 

[Geekything]

Thank you cacher_chick and Terry for your help and patience.

If anyone else finds this thread in the future, I found this presentation quite helpful.

 

[Cacher_Chick]

Thank you cacher_chick and Terry for your help and patience.

If anyone else finds this thread in the future, I found this presentation quite helpful.

That presentation is evidence of things that are permitted in Canada, but most would not be approved in the U.S.

 

[Geekything]

I just read somewhere that we're allowed plumbing and electrical in HVAC returns. Which is good because I just found some