Wall hung toilet

[Andrew Pirrello]

Hi all, My question is regarding a Wall hung toilet. Would venting out of the 2" hub in the low heal, then 90-ing with a street elbow and connecting the toilet with a shielded Fernco be permissible?

I included a couple pictures to make visualizing it easier.

 

[Reach4]

I think yes:
https://terrylove.com/forums/index.php?threads/san-tee-vs-90-with-low-heel-inlet.2795/
https://terrylove.com/forums/index.php?threads/toilet-vent.37885/

 

[Sponsor]

 

[Andrew Pirrello]

I think yes:
https://terrylove.com/forums/index.php?threads/san-tee-vs-90-with-low-heel-inlet.2795/
https://terrylove.com/forums/index.php?threads/toilet-vent.37885/

Thanks for the reply, I really appreciate it.

 

[wwhitney]

If the wall hung toilet elbow permits rotating 45 degrees, it looks like you could eliminate the LT90: replace the low heel 90 with a 3" wye with 2" bushing in the straight inlet for the vent, and point the wall hung elbow at the wye branch inlet. But perhaps I am misjudging the geometry and the wye would end up lower than is convenient.

Cheers, Wayne

 

[Andrew Pirrello]

If the wall hung toilet elbow permits rotating 45 degrees, it looks like you could eliminate the LT90: replace the low heel 90 with a 3" wye with 2" bushing in the straight inlet for the vent, and point the wall hung elbow at the wye branch inlet. But perhaps I am misjudging the geometry and the wye would end up lower than is convenient.

Cheers, Wayne

Ahh, great idea, I'll check if there's clearance for that. I think there will be.

 

[Andrew Pirrello]

If the wall hung toilet elbow permits rotating 45 degrees, it looks like you could eliminate the LT90: replace the low heel 90 with a 3" wye with 2" bushing in the straight inlet for the vent, and point the wall hung elbow at the wye branch inlet. But perhaps I am misjudging the geometry and the wye would end up lower than is convenient.

Cheers, Wayne

Dry fit looks promising

 

[Tuttles Revenge]

Yes, either configuration is OK per Geberit installation instructions that the provided drain fitting must point vertical down prior to offsetting horizontal. 45 or 90 are acceptable and 45 is preferable. Not sure if any other manufactures have OK'd that method officially, but I can't see how it would hurt since they all are cross compatible.. Or at least Geberit has tested every other manufactures toilets to fit their equipment.. not the other way around.

 

[Andrew Pirrello]

Yes, either configuration is OK per Geberit installation instructions that the provided drain fitting must point vertical down prior to offsetting horizontal. 45 or 90 are acceptable and 45 is preferable. Not sure if any other manufactures have OK'd that method officially, but I can't see how it would hurt since they all are cross compatable.. Or at least Geberit has tested every other manufactures toilets to fit their equipment.. not the other way around.

I'm running into an interesting problem with this install. The inspectors cannot agree that it's permissible. The Oregon state office is OK with the wye/vent, but my local inspector says that the vent pipe opening needs to be above the trap weir.

 

[Andrew Pirrello]

Without getting too deep into this, the state office cited this section of the Oregon specialty code:
905.5
"The vent pipe opening from waste pipe, except for water closets, and similar fixtures, shall not be below the weir of the trap"

Any thoughts
Kind regards,
Andrew

 

[Terry]

Toilets have always been allowed to have vents lower. The bowl is designed to siphon and then gets refilled from the tank.
I guess your inspector has never seen a wall hung toilet before. It's going to be a good education for him.

 

[Andrew Pirrello]

Toilets have always been allowed to have vents lower. The bowl is designed to siphon and then gets refilled from the tank.
I guess your inspector has never seen a wall hung toilet before. It's going to be a good education for him.

I've been getting one heck of an education too, thanks to solid resources such as these forums

 

[wwhitney]

Any thoughts

That your local inspector doesn't understand the meaning of the words "except water closets"?

But seriously, your local inspector is used to see a san-tee for venting a horizontal trap arm while it turns downward, rather than a wye or combo. They apparently don't realize that 905.5 is the codification of the reason for that. Since 905.5 exempts water closets, they can be vented with a wye.

Also, ask the local inspector to think about a normal bottom discharge water closet. The trap is internal to the WC. The discharge is already well below the trap weir. The vent connection on a WC is always below the trap weir. And I believe it needs to be, so the WC will siphon and empty (presumably the reason the Gerberit installation manual says the wall discharge elbow can be no more than 45 degrees off plumb, thanks to Tuttle for pointing that out).

Cheers, Wayne

 

[Andrew Pirrello]

"And I believe it needs to be, so the WC will siphon and empty"

Very good point here that I hadn't thought of: the trap for a WC is actually intended to siphon, and, unlike most other fixtures, it is self-priming from the tank. Did I follow that correctly?

 

[wwhitney]

Yes, particularly the self-priming from the tank part, i.e. the little extra tube that sends water into the bowl while the tank is filling.

Cheers, Wayne