How does a soil stack differ from a waste stack?

A soil stack is specifically designed to carry human waste, including fecal matter, which is a critical aspect of plumbing systems that handle sanitary waste. This type of stack is usually part of a building's drainage system that transports sewage to treatment facilities or sewer systems. In contrast, a waste stack is intended for discharging waste water that does not include human fecal discharges, such as greywater from sinks, showers, or laundry.

This distinction is important in plumbing design and maintenance, as the materials and systems used must be appropriate for the type of waste being handled to ensure proper sanitation and avoid contamination. The separation of soil and waste stacks is also essential for regulatory compliance and health standards in building codes.