Mechanicals · definition
Older quiet but corrodible drain piping. Deteriorated cast iron under slabs/in stacks is a common reason for invasive plumbing work.
Source: Cast Iron Soil Pipe Institute — Cast Iron Soil Pipe
Where this term lands on a Columbus budget
The cost pages carry the current local ranges, and the guides explain what moves them. A published range becomes a project number only after someone looks at the site.