Cast Iron Drain Lines: What Multifamily Owners NEED to Know Cast iron drain lines are one of the biggest hidden risks in older multifamily buildings — especially in the Southeast. Most failures don’t happen overnight… they happen slowly, and the signs get ignored until repairs become very expensive. Here’s a quick breakdown so you know what to watch for: 🔧 How Cast Iron Fails Cast iron breaks down from the inside out due to: - Corrosion (rust) - Scaling - Hydrogen sulfide gas - Acidic wastewater - Age (most fail between 40–60 years) By the time you see problems above ground, the inside of the pipe is usually in rough shape. 🚨 Early Warning Signs to Watch For If you see ANY of these in a unit, post photos immediately: ✔ Slow drains ✔ Gurgling noises ✔ Backup in tubs or showers ✔ Rotten-egg smell ✔ Water stains on ceilings ✔ Soft floors around tubs or toilets ✔ Repeated plumber visits ✔ Black sludge coming up through drains These almost always point to internal corrosion or scale buildup. 🛑 Major Red Flags (High-Risk Situations) These mean the pipe is failing: - Bellies or dips in the line - Cracks or fractures in the pipe - Heavy scaling - Missing bottom of the pipe (“channel rot”) - Roots entering through joints - Large amounts of white/gray epoxy residue from old spot repairs If you have any of these, expect future failures. 💰 Typical Repair Options & Price Ranges Southeast U.S. multifamily pricing: Spot repair: $1,200–$3,500 per section Reroute (above slab): $2,500–$6,500+ Full building repipe (multifamily): $8,500–$30,000+ per stack (varies heavily) Epoxy lining: $150–$300 per linear foot(pros/cons — depends on condition) 🏚️ The “White Coating” You Sometimes See If your sewer scope shows white or light gray coating, that’s typically: - Epoxy lining - Descaling compound - Mineral buildup - Internal corrosion flakes Not all “white” = epoxy.If you’re unsure, upload your scope photos and I’ll interpret them. 📸 Post Your Cast Iron Photos or Scope Videos