I ran into this section of text while reading up on something else and it is very puzzling to me. This is a section of the Ontario building code as it relates to wet venting.

This is the link to that section:

[www.buildingcode.online]

This is the text that is puzzling to me. I copied the entire wet venting section so to not quote something out of context, Can the pros look at sub sections (h) and (i) where it talks about "extending wet venting through more than 1 story"? I thought wet venting is not even allowed outside of the same bathroom group on the same floor, but am I reading this right they are allowing it to extend up to a second floor?

The Ontario Building Code | Wet Venting

7.5.2.1. Wet venting

(1) A soil or waste pipe may serve as a wet vent provided that,

(a) the hydraulic load is in accordance with Table 7.5.8.1.,

(b) the number of wet vented water closets does not exceed two,

(c) when two water closets are installed, they are connected at the same level to a vertical part of the stack by means of a double fitting in accordance with Table 7.2.4.5.,

(d) the water closets are installed downstream of all other fixtures,

(e) trap armsand fixture drains connected to the wet vent do not exceed 2 in. in size, except for connections from floor drains in accordance with Clauses 7.5.1.1.(3)(a) to (c),

(f) the total hydraulic load on the wet vent does not exceed the limits stated in Table 7.5.8.1. when separately vented branches or fixture drains in the same storey, having a total hydraulic load not greater than two fixture units, are connected to a wet vent or a wet vented water closet trap arm,

(g) the hydraulic load of separately vented fixtures that drain into the wet vent is not included when sizing the continuous vent that serves the wet vent,

(h) where a wet vent extends through more than 1 storey, the total discharge from any 1 storey above the first storey does not exceed four fixture units,

(i) where a wet vent extends through more than 1 storey, there is not more than one nominally horizontal offset in the wet vent, and,

(i) the offset does not exceed 1 200 mm for pipes 2 in. or less in size, or
(ii) the offset does not exceed 2 500 mm for pipes larger than 2 in. in size,

(j) the wet vented portion is not reduced in size except for the portion that is upstream of floor drains in accordance with Clauses 7.5.1.1.(3)(a) to (c),

(k) the highest fixture is connected to a vertical portion of the wet vent, upstream of any other fixtures, in the form of a continuous vent, and

(l) the length of the wet vent is not limited.



Edited 1 times.

The building code department can allow ANYTHING they want to. Some allow NO "wet vents", some allow it within a single floor, others between floors, and the "Philadelphia single pipe system" allows sinks to be wet vented through several stories.

good to know...I was under the assumption that most jurisdictions are based on UPC and IPC, then they can impose more restrictions over that depends on the locale. I did not know they can make exception to make it less restrictive.

I can personally say Philadelphia has its own code. Not sure about any other cities, but Philly code is extremely poor is some aspects and major overkill on others when it comes to “code”

interesting, this is the Philidelphia single vent stack system hj mentioned.



it says it's allowed by IPC and it requires an oversized vent and successful use of S-traps.

..... As I have stated before: Code, while providing a minimum standard, is far too often not best practice. .....

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

The drawing does not show "S" traps, and using them would defeat the reason for having that system. Now, if using a cast-iron "So-Vent" or the equivalent plastic pipe version, that would be a different thing.

I can run a 22’ 1.5 trap arm in Philly before it has to vented, from the vent 10’ to the ideal bend then another 12’ off that to a tub or sink no vent on any fixture just the stack vent like I said overkill and too simple at the same time… to avoid issues I plumb in the city just like I would in the burbs it just easier

What is an "ideal bend"?

22' of trap arm? wow...that will allow for no air space to vent if it's plumbed at 1/4" per foot, 6' will seal off the air inside the pipe for a heavy flow. Do they plumb the trap arm at 0% slope?

I still haven’t figured out how to post a pic here or paste a link
Google ideal bend

Basically it’s a closet bend with 2 1.5 tappings that can be oriented in many different ways

Sum the slope is still 1/4” per foot

Like I said I have not done this personally but Philly says you can and it does work I’ve been in old houses and everything drains just fine and doesn’t seem to suck any traps