Venting a WC

[Carl Martin]

I saw these diagrams on Better Homes & Gardens and am wondering if they are code compliant for IPC. I'm specifically wanting to use the configuration on the right. Is it good to use?

Generally, I understand that you can't have a horizontal vent below 6" above the floodline, so how can they say this is code compliant?

 

[wwhitney]

Those diagrams are outdated and not code compliant, your latter comment is correct.

Cheers, Wayne

 

[Sponsor]

 

[Carl Martin]

Thanks, Wayne.

If I were to configure the rightmost configuration so that the vent never drops below 45 degrees, that would be acceptable, right?

I'm replumbing an old bathroom where the WC was sitting on top of an old cast iron waste stack, so I can't think of any other options than adding a couple of 90s to go out and back.

 

[wwhitney]

If I were to configure the rightmost configuration so that the vent never drops below 45 degrees, that would be acceptable, right?

Yes, a vent that is at least 45 degrees above horizontal is considered "vertical", so it complies with the rule that the vent stay vertical until at least 6" above the fixture flood rim.

I'm replumbing an old bathroom where the WC was sitting on top of an old cast iron waste stack

So hopefully you can put your vent wye low enough on the stack that the vent can rise at a 45 degree angle and make it into a wall before emerging above floor level.

Also, if the next lower drainage connection to the stack stack is the drainage from a dry vented lav, shower or tub (via a drain is only carrying bathroom fixtures), that drain connection may be used as a wet vent, eliminating the need for a dry vent. For the IPC, such a wet vent could be 1.5" if carrying only one lav, but would otherwise need to be at least 2".

Cheers, Wayne

 

[Carl Martin]

I think I have plenty of space for the 45 degree vent, but it will also fit in the the category you mention of venting a single bathroom group. Does this fit into the allowances in 912.1?

 

[wwhitney]

I think I have plenty of space for the 45 degree vent, but it will also fit in the the category you mention of venting a single bathroom group. Does this fit into the allowances in 912.1?

Perhaps, although since you spoke of a stack, the option in the last paragraph of my previous post is more like vertical wet venting.

Cheers, Wayne