Referral service, not a contractor. SF Drain & Sewer Pros does not perform plumbing, drain, or sewer work. Calls to (415) 555-0100 are connected to an independent, licensed local provider, who may pay us for the referral. Always confirm the provider's license and get a written estimate. How this works
Cast iron drain pipes in older homes
Cast iron was the standard material for drain and vent piping in many older buildings. It's durable and quiet, but it corrodes from the inside over decades.
How it fails
- Scale and tuberculation: corrosion buildup that narrows the pipe and snags debris
- Channeling: the bottom of horizontal pipe wears thin or splits lengthwise
- Cracks, especially at fittings
Signs
- Recurring slow drains despite clearing
- Rust-colored stains or dampness around exposed pipe
- Sewer odor near walls or floors
Options
- Descaling with specialized cutting heads, sometimes as a step before lining
- Spot replacement of failed sections, often with PVC or ABS, using proper transition couplings
- Lining to restore the pipe from inside
- Full replacement when damage is widespread
A camera inspection is the starting point (what it shows). Get quotes for both lining and replacement where both are feasible.