Do Copper Pipes Wear Out From Inside?

 GROK:

Yes, copper pipe does wear out from the inside over time, but how fast (or whether it happens at all) depends heavily on water chemistry, flow conditions, and installation quality.

Here are the main ways copper pipes degrade internally:

1. Erosion-Corrosion (most common cause of "wear")
   • High water velocity (> 5–8 ft/sec in cold water, > 4–5 ft/sec in hot water) literally erodes the copper.
   • You see this as smooth, horseshoe-shaped pits or long grooves pointing downstream (“pinhole leaks from erosion”).
   • Very common in homes with oversized pumps, poorly sized lines, or turbulent fittings (sharp 90° elbows, partially closed valves, etc.).
2. Pitting Corrosion (Type I, II, or III pitting)
   • Type I: Cold water, low pH (< 7.2) + high CO₂ or oxygen → deep, narrow pits. Common in soft, acidic well water.
   • Type II: Hot water > 140°F (60°C), soft water, pH 7.2–7.8 → broader pits under blue/green copper sulfate mounds.
   • Type III: Cold water, high pH (> 8) + very soft water → similar but less common.
   • Eventually pits go all the way through → classic pinhole leaks.
3. Uniform Internal Corrosion / “Blue Water”
   • New copper installs leach copper for the first few years until a protective oxide layer forms. Excessive leaching stains fixtures blue-green and can taste metallic.
4. Microbiologically Influenced Corrosion (MIC)
   • Rare, but bacteria can accelerate pitting in stagnant or low-flow lines.

Real-world lifespans

• Favorable water chemistry (pH 7.2–7.8, moderate hardness, low velocity): 50–100+ years, often outlives the house.
• Aggressive water + high velocity: pinhole leaks in 10–25 years (some homes see failures in under 10 years).
• Very aggressive well water: failures in 5–15 years are not unusual.

Signs it’s wearing out internally

• Recurrent pinhole leaks
• Blue-green stains around leaks
• Metallic taste or turquoise staining in sinks/toilets
• Reduced flow from internal roughness or partial blockages (rare)

So yes — copper pipe absolutely can and does “wear out from the inside,” but in many cases it lasts virtually forever if the water chemistry and flow velocities are kind to it.