Plumbing Stack

[R3Improvements]

I'm remodeling my attic bathroom. In order to maximize my bathroom, I would like to put an elbow in my existing cast iron plumbing stack, run about 3feet of horizontal pvc, and then put another elbow in and vent it through the roof. The stack currently runs right through the middle of my attic bathroom. So by moving it over 3 feet, I can create a better floor plan. Is this against code to use 90 degree elbows in the main vent stack?

Thanks.

 

[Seaofnames]

It is ok as long as there is some pitch to the horizontal run and it is about 40" above the floodline of the fixture(check your local code for that)

Also make sure if you are putting a new hole in your roof the stack goes up high enough, as there may be a code in your area that wants it higher than minimum code.

In my area(Vancouver Canada) they require cast iron behind the walls because it isnt flammable. This is just a commercial thing, but I'd still check with your local inspector to see if they want cast or if PVC is ok.

 

[Sponsor]

 

[R3Improvements]

Can the slightly pitched horizontal section be at the same level as where the toilet ties in or does the horizontal section need to be 40" above this connection?

Thanks.

 

[Seaofnames]

I'm sure you can run it so that it does not tie into the vent from the lower floors.

Terry, can you post that fancy 'proper' way to plumb more than one story?

 

[Terry]

You can use 90 bends above the flood level.

 

[hj]

vent

I suspect you cannot use that vent stack for the upstairs bathroom, so it can offset at any elevation.