The main vertical drain line in a building that receives waste specifically from toilets and urinals, routing it downward to the sewer. The upper portion of this pipe extends through the roof to allow sewer gases to escape and to let air into the system, preventing a vacuum from pulling water out of the fixture traps.
Heard on the job
We need to cut a wye into the cast iron soil stack to tie in the new powder room toilet.
Also heard as
- soil pipe
- main stack