Venting Tie-In - Dumb Question

[MarktheRed]

Hi Experts. Doing a remodel in my basement and have a question as to the best tie-in a vent from a new laundry area to the existing vent stack.

This horizontal vent will ONLY be for venting and I have some concerns about using a double wye as it will create a trap for the sewer gases in the pipe. However, I know island kitchens do this sort of thing, but was unsure of it in this application. I have very little headroom to work with (7' ceilings).

Can I use a double wye to connect a horizontal vent to this main / drain? In other words, the horizontal vent will inevitably curve downward at the tie-in like the current single wye connecting the toilet.

I like a wye connector because there is zero chance drainage from the adjacent toilet drain will flow back up it and plug it? If I horizontal tie-it in, I fear I run the risk of plugging from the adjacent toilet due to low headroom, I effectively need to tie it at the same location.

I attached a picture and a sketch. Appreciate the support as always. Hope this makes sense.

 

[wwhitney]

The simple answer is that you can't connect a vent there. When two vents join, the connection has to be at least 6" above the flood rim of all the associated fixtures. So to join the laundry vent to the existing WC vent, you have to bring the laundry vent up to at least 6" above the WC's flood rim.

Cheers, Wayne

 

[Sponsor]

 

[MarktheRed]

Thanks Wayne. I guess I gotta start fishing through walls to create my own drain stack.

 

[Helper Dave]

If you have a floor drain that was individually vented, that's often a solid spot to tie basement fixture vents into.

It'd be nearish the floor drain, and generally the only 1 1/4" or 1 1/2" pipe going into the basement floor. Run any fixtures above, and listen/feel for drainage if you're at all uncertain.

But then, floor drains can vent in other designs, so that pipe might not exist at all.