Many older homes in North Texas were built with cast iron drain lines under the slab. Newer homes generally use PVC. If you own an older home, your drains may be original cast iron.
How cast iron fails
Cast iron usually fails from the inside out:
- Scaling: rough buildup inside the pipe narrows it and catches paper and debris
- Corrosion: the bottom of the pipe wears thin, then cracks or opens up
- Cracking: soil movement under the slab stresses old, brittle pipe
- Root intrusion: roots get in through cracks and joints
Warning signs
- Recurring clogs in the same drains
- Slow drains throughout the house
- Sewer smell
- Signs of a slab leak, like warm or damp floors (for water lines) or musty smells and floor cracks
Buying an older home? Get a sewer camera inspection
A standard home inspection usually doesn't include a camera inspection of the sewer line. For an older home, it's one of the most valuable checks you can do before closing.
Repair or replace?
If the camera shows one bad section, a repair may be the right call. If the line is scaling and cracking throughout, replacing it with new pipe is usually the better investment than repeated repairs.