Shower Drain Connection

[Akramg]

We are at the stage where we're shopping around for a shower drain, and learning that most the shower drains are 2" or 3". Our existing shower drain is 1.5" at the sanitary tee. The tee is 1.5" female on all 3 sides; I attached a close up image.

Is there a sanitary tee i could purchase, which would be 1.5" female x 1.5" female x 2" male? If not what other options do we have? I would love to avoid having the drain hole any higher than it is already, and to try an be as minimally invasive to the existing drainage system as possible.. I am hoping i can carefully remove the existing tee, and install a new one with a male 2" so that the 2" female shower drain would go over top of it.

Thanks!

 

[Breplum]

Honestly, there is no nice way to put this but your desire for a shower drain is not going to end up with a perfect answer.
Shower drains now are 2" for a reason, and UPC code changed to make it 2" so that they will drain well. You should demo back to larger pipe. And, that tee with supposed vent is NOT to code.
I actually have a 1.5" old copper drain in one of my showers and it works ok but in your position where you can do it right, that would be what I recommend.
There are definitely shower drains out in the marketplace in 1.5".

 

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[Akramg]

Honestly, there is no nice way to put this but your desire for a shower drain is not going to end up with a perfect answer.
Shower drains now are 2" for a reason, and UPC code changed to make it 2" so that they will drain well. You should demo back to larger pipe. And, that tee with supposed vent is NOT to code.
I actually have a 1.5" old copper drain in one of my showers and it works ok but in your position where you can do it right, that would be what I recommend.
There are definitely shower drains out in the marketplace in 1.5".

Good morning Breplum, thanks for your response! I looked up the NPC used in Canada and they allow a minimum shower drain of 1.5" if you use only 1 head/conform to certain flow rate requirement in the newer codes.

I agree with you that upsizing everything to 2" is the best way to go, i don't know how deep below the ground i'd have to dig and how far this 1.5" drain line runs. i am also not enthusiastic to do that

Could you please explain why the tee is not to code? We've recently purchased the home and have demo'd the washroom only to find that.

Also, for the 1.5" drains, do they accommodate a traditional mortar bed with pvc liner tile bath floor installation?

Thanks much!

 

[wwhitney]

As far as that san-tee, I see a trap that you removed sitting in the background of the first picture. How did that trap connect to the tee? Also, you mention in the OP connecting a shower drain directly to the top of that tee, looks like that would result in no trap, which is obviously not allowed.

Two likely problems. First a trap need a vent that connects to the trap arm (the outlet side of the trap) before the drain has fallen more than one trap diameter. So if the trap connected to that san-tee via an elbow, the side connection on the san-tee would be too low in elevation to be a vent.

Second, most codes require a vent to be taken off vertically, not horizontally, and rise (at least 45 degrees above horizontal) until at least 6" above the fixture flood rim. So that would mean no horizontal vents under the slab. You'd need to check the NPC to see if it has any applicable exceptions to those requirements.

Cheers, Wayne

 

[Akramg]

As far as that san-tee, I see a trap that you removed sitting in the background of the first picture. How did that trap connect to the tee? Also, you mention in the OP connecting a shower drain directly to the top of that tee, looks like that would result in no trap, which is obviously not allowed.

Two likely problems. First a trap need a vent that connects to the trap arm (the outlet side of the trap) before the drain has fallen more than one trap diameter. So if the trap connected to that san-tee via an elbow, the side connection on the san-tee would be too low in elevation to be a vent.

Second, most codes require a vent to be taken off vertically, not horizontally, and rise (at least 45 degrees above horizontal) until at least 6" above the fixture flood rim. So that would mean no horizontal vents under the slab. You'd need to check the NPC to see if it has any applicable exceptions to those requirements.

Cheers, Wayne

thank you Wayne

I attached an image of what it used to look like. I think the previous homeowner/installer did that because the fibre glass tub drain location is offset from the drain at the tee, but i don't know...?

As for the P-trap for the shower drain, i'm thinking it's buried down underneath the sanitary tee? I suppose that doesn't change anything about the trap arm needing to be vented to your point.

Hopefully the video attached shows can help tell a better story, the ending zooms out and show the system:

The water level stays constant, before and after flushing water through it. I tried getting a cheap boroscope down through the vertical of the tee and eventually made it to what i think was the bottom of P-trap. I'm thinking so because i saw what looks like the cleanout of the P-trap. Camera couldn't get past that point so i will have to re-enforce the camera cable to hopefully get to the other side of the P-trap and explore.

Appreciate the support!
Akram

 

[wwhitney]

Well, the previous configuration shown in the picture is definitely wrong, and extra wrong if in fact you have a trap below the san-tee, so that the previous configuration was double trapped.

What you are going to need to do for a shower is get to a configuration in which you a vertical tailpiece coming out of the slab, a trap below that, a horizontal trap arm coming off the trap to a point where a vent can come off vertically (which includes anything at least 45 degrees above horizontal) and rise vertically to connect to your vent in the stud bay.

So unless you can somehow confirm a trap down there, and confirm that the trap's trap arm has some other vent connection to it, you'll need to break up some concrete. If you are lucky, in doing that you'll find a 2" drain you can tie into, which will render moot your original question.

Cheers, Wayne