Basement vent question

[wallbobby]

This is probably a dumb question, but I thought I'd make sure before doing a bunch of extra work... There's a dry vent line that goes from the bottom of my slab in my basement up through the roof (2 story house including basement). It services a sink on the upstairs floor. Because of this, it can't have any horizontal whatsoever below that sink (ie, the basement ceiling), correct? Because it's below the flood line of that sink?

I ask because 1) there's a lav in the downstairs that vents to that pipe too, but it runs horizontally before it joins it, which I'm assuming was ok when the house was built 70 years ago but is not today? (So I have to fix that.) 2) If I could tie into that vent for other basement fixtures it would save me running a new vent.

Thanks!

 

[Terry]

A dry vent can be tied into at six inches above flood level on any floor.

If it's a wet pipe, it can't be used for a vent.

 

[Sponsor]

 

[wallbobby]

A dry vent can be tied into at six inches above flood level on any floor.

If it's a wet pipe, it can't be used for a vent.

Thanks - it's a dry vent. But because it serves the floor above, it can't be tied into below the first floor, right? (that is, I'd have to run above six inches of the first floor fixture that uses it as a dry vent) That's what you meant by "any floor" - above the flood levels of all floors involved, right? There is a very logical place to tie into it, but it's in the ceiling of the basement (below the floor of the upstairs where that sink is). I'm assuming this is a no-no.

 

[Terry]

That would still be above flood level in the basement. Six inches or higher.

 

[wallbobby]

Ahh, I think I understand now. This may save me a ton of work, poking a new vent out. And fortunately this one is 2" after it transitions above the basement ceiling, so it should be able to vent my basement bathroom group.