Hi,I live in Toronto, I'm confusing about the WC venting

[Nixgnoy]

Hi, I live in toronto, I need to add bathrooms on the third floor and the second floor. And got 2 problems while doing plumbing.
1)on the Area 'A' , the trap arm for the 3rd. Floor WC is 4' but it has an offset to the soil stack which is 1' in length (see the Area 'B'); so total is 5' right? I just heard that trap arm for WC should not be exceed at 5' but I check Canada code it says it can be a maximum of 3m in horizontal and 1m in vertical. Very confusing. Do I need to add an extra vent for the 3rd WC?
2) similarly question for the Area 'C'; do I need to add a vent for this 2nd floor WC? But it just 2' on its trap arm.
3)any other mistake in my draft pls let me know; I'll be very appreciated. Thank you so much!

 

[Terry]

You can't "wet vent" between floors.
Any bathroom below will have it's vents go up past the next floor.
In your drawing, you dump an entire bathroom down the toilet vent from below. Can't happen!
I don't think the law of physics changes North of the border.

 

[Sponsor]

 

[Nixgnoy]

Hi Terry, thank you for ur help, I'v already vent the sink and shower on 2nd floor, except the WC, but code says WC working base on siphon and don't need vent within 3m, now it's just within 2'， do u think I still need a vent？

 

[Terry]

Hi Terry, thank you for ur help, I'v already vent the sink and shower on 2nd floor, except the WC, but code says WC working base on siphon and don't need vent within 3m, now it's just within 2'， do u think I still need a vent？

But not on different floors.
When the toilet above flushes, it will displace water in the bowl below.

 

[Nixgnoy]

Hi Terry, I'm still confusing, can u explain a little more?
u mean every fixture need a vent? Including all WC right? Coz venting a WC seems more difficult than vent other fixtures, if I don't vent those WC that shows in my diagram, it could be not perfect but do u think it still match the code? Coz I don't find out some clauses in the code saying that WC need venting within 3m horizontal and 1m vertical. Thank you so much!

 

[hj]

"U" and "COZ"? Drop the speed writing.
The WC does NOT need a vent when IT is flushing, it needs one when the upstairs one is flushed. Two different situations. It is a function of the code and inspector whether they will allow the "Y and 1/8 bend" for the third floor toilet connection, even though the toilet is an "S" trap, and the Y-1/8 bend just extends it.

 

[Nixgnoy]

Thank you HJ, I'd like to know what is proper way to run the pipe in my situation? Just add a vent for 2nd floor WC, that's it? Thank you very much!
I quote the diagram again:

 

[Terry]

You can do it anyway you like. You're a long way from me in Seattle.

I'm just saying that when you flush the upstairs toilet, you will lose water in the downstairs bowl they way you intend to plumb it. I know this for a fact.
But I think you should do it that way, and then report back. We would love one more example of why plumbers don't do what you intend to do.

 

[hj]

quote; Just add a vent for 2nd floor WC, that's it?

I like how that rolls so freely off the tongue. Now let's see HOW you do it.

 

[Nixgnoy]

Hi Terry, HJ, thank you very much! I'll do them as soon as possible!