Can you use PEX for venting ?

[Mini Me]

Just to be clear I am a DIYer, please excuse the naivety of the question if it is so

Is there such an option as using PEX for an 1-1/4 vent ? I have a stretch where I need some flexibility for my pipe which is going to be difficult to achieve with copper or ABS.

 

[WorthFlorida]

Most likely no. May depend on your local jurisdiction but the vent needs to be positioned should any water entering it from the roof or from an overflow, it must drain completely. Therefore, no dips and any horizontal runs must be sloped. A problem is the fittings may reduce the inside diameter. In the 2018 IPC codes it does mention PE (polyethylene) but it does not list "crosslink polyethylene" (PEX) for drainage or venting.
https://codes.iccsafe.org/content/IPC2018/chapter-7-sanitary-drainage

You should call your local building department. Is it possible to use an AAV. As long there is one roof vent somewhere else, an AAV may work for you.

 

[Sponsor]

 

[Jeff H Young]

1 1/4 vent is rare you wont find that in abs any way. Whatever it is your doing doesent sound like a good Idea

 

[Reach4]

They make 1-1/4 spa hose, such as SpaFlex, which is PVC with a lot of extra plasticizers. It can be glued into pvc fittings. I expect there is a rule against that for this use as venting. I think its intended use is for swimming pool recirculating filters. I am not a plumber.

 

[Mini Me]

I have a 1-5/8 (1.5" ID?)vertical vent that comes of the soil stack on the main floor
It probably vents the sink on that floor and then it goes dowsntairs with no role (Jeff we talked about that damn pipe)
Now I want to cut the bottom part off and just below the ceiling in basement I want to route that toward the wall and use this as dry vent for my shower and my sink in the basement. I could use a wet vent there but that is another story

So in my attempt to reroute that 1-5/8" copper vent toward the wall I run into a problem: I need to go through an space left between the soil stack and a 2" drain that joins the main stack as in this picture. I need to go across the red line. That space can barely take a 1-1/4 copper, I still need to carve out the 2 2x8s there fir like less that 1/8 to make it work

 

[Reach4]

I have a 1-5/8 vertical vent that comes of the soil stack on the main floor

If that is 1-5/8 OD, it is usually called 1-1/2 inch copper.

 

[Mini Me]

yes you replied while I was editing this

What can I use to transition from 1-1/5" to 1-1/4"? A ZI connector?

I am considering this:
Go from 1-1/5" to 1-1/4" copper using a ZIP connectore (trying to avoid soldering) there will be no water in this branch vent)
After I do the transition I can use a 45 and a 90 elbow to get the the level of that opening and run trough it with a 1 -1/4 copper ...after that I will use another transition from 1-1/4" copper ot 1-1/2" ABS which I will run through the walls to build my dry vents

I am building this

 

[Mini Me]

grrr I just realized that 1-1/4" is not ok for venting...