Cast Iron Drain Pipes: When to Repair, When to Replace

Cast iron drain pipe was the standard for residential drain-waste-vent systems from the early 1900s through the 1970s. It's heavy, durable, and — when it was installed — expected to last 50 to 100 years. Many of those pipes are now 50 to 80 years old, and they're reaching the end of that range.

Cast iron fails in two ways. The first is internal corrosion — the pipe rusts from the inside out, creating rough surfaces that catch debris and eventually developing holes. The second is joint failure — the lead-and-oakum joints used in older installations can crack and separate, allowing sewage to leak into the surrounding soil or structure.

A camera inspection is the only reliable way to assess the condition of cast iron drain pipes. We look for active corrosion, joint separation, cracks, and areas where the pipe has collapsed or deformed. The condition varies significantly from house to house depending on water chemistry, soil conditions, and how the system has been used.

When we find cast iron in good condition — smooth interior walls, intact joints, no cracks — we leave it alone. Cast iron that's still sound is a perfectly good pipe. When we find significant corrosion, joint failure, or structural damage, we recommend replacement.

Replacement options include PVC (most common for residential), ABS, and cured-in-place pipe lining for sections that are difficult to access. We'll give you an honest assessment of what's worth repairing and what needs to go. Call 313-427-4780 to schedule a camera inspection.