Not an expert but two questions - I assume this is the freshwater line:

1) Do you have to run it through a stud? On my current bathroom project I moved the cold water to the tub and just re-drilled the floor. Wasn't hard.

2) Why 2" pipe? My feed is 1/2" (5/8" OD) copper line.

 

I take it your talking about a vent stack not a supply line?

 

Never mind.

 

OD of 2" abs is as you say 2.38", you would probably drill a 2.5" hole to route pipe. That would leave you 0.5" on each side of a 2x4. If it was me, I would use the 2x6 and cover with nailing plate to protect against a nail or screw penetrating the pipe.

 

2" ABS vent pipe thru' 2x4 stud (non-bearing)

I'm swapping the toilet location w/ the bathroom sink location, and it's the new 2" ABS vent pipe for the new toilet location I'm talking about.

There'd be a 1 1/2" ABS vent pipe for the swapped bathroom sink.

These two vent pipes would merge inside the wall, and a single vent pipe would go up to the attic and thru' the roof.

I'll need to merge the new 2" vent pipe back to the old galvanized vent pipe location (this is a 55 yrs old house) that's why it needs to go thru' the studs.


Another way perhaps, so don't have to change out the whole wall to use 2x6 studs instead?

 

Could the vents pipes both go separately into the attic and then combine there? Would that allow you to just run them straight up in the stud bay and not go through the studs?

 

Not sure about how correct it is, but I have a similiar issue with my venting, and I am going to run it horizontal outside the wall and box it in with a bulkhead instead of going through the 2x4's. Might look a little odd, but I don't want to jeopardize the wall or beef it up and noone will be the wiser. So this might be a secondary solution to think about.

 

There are bathrooms on both sides of the wall. Toilets and sinks/medicine cabinets on both side of the walls.

So can't run the vent pipes outside the wall.

 

Can you run them separately up into the attic?