Basement bath venting

I'm installing a basement bath. My plan is to run the vent (3") up 8', then 90 across between the floor joist 20' to the outside, then striaght up.

Will that much horizontal distance cause problems? Thanks.

In many codes, a bathroom can be vented with a 2" vent, if other vents are also present.

With that 2" vent, you would be allowed 1/3 the distance horizontal to the vertical.

Or you could increase the vent to 2-1/2" and run pretty much as long as you like.

I would say that the 3" will do just fine.

vent

We don't know where you live, but if it is in a cold area, the outside pipe going up to the roof, (you don't intend to just stick the vent through the wall, I hope), can freeze closed, and that would create a problem.