Key takeaways
- Cast iron corrodes from the inside, building scale.
- Scale narrows the pipe and causes clogs.
- Pinholes and cracks lead to leaks.
- Descaling plus lining renews the pipe without demolition.
Why cast iron corrodes
Wastewater, moisture and gases attack the iron from the inside over decades. The corrosion builds rough scale called tuberculation, which can shrink the pipe's opening.
Signs of trouble
Slow drains, frequent clogs, rust-colored water at cleanouts and leaks at stacks or under slabs all point to corroding cast iron.
Repair options
Replacement means demolition of walls, floors or slabs. Lining descales the pipe and installs a smooth, corrosion-proof liner, often with minimal demolition.
When lining may not work
If the cast iron has failed structurally or is badly broken, a liner may not be sufficient. A camera inspection tells you the condition.
Related services
Ready for a firm answer on your own pipe? Try the Pipe Problem Finder or call 800-224-9245 for a free camera inspection.