How to Inspect Visible Pipes for Damage
Your home's exposed pipes tell a story about the health of your entire plumbing system. Corrosion stains, mineral buildup, and physical damage on visible pipes are early warning signs of problems that could escalate into leaks or bursts. A thorough visual inspection now can catch issues before they cause expensive water damage.
Quick Summary
Time Required
20-30 minutes
Difficulty
Easy
Who Should Help
No help needed
Where to Find Exposed Pipes in Your Home
Before you start inspecting pipe conditions, make sure you know where all the visible pipes are. Many homeowners overlook pipe runs in less-visited areas.
Basement or crawl space ceiling
This is where most of your home's main supply and drain lines run. In unfinished basements, pipes are typically attached to the underside of floor joists. Bring a good flashlight and walk the full perimeter, following pipe runs from the water main entry point to where they branch off to different parts of the house.
Under sinks and vanities
Remove everything stored under kitchen and bathroom sinks. Inspect the supply lines, shutoff valves, drain P-traps, and all connections. These are the most common locations for slow leaks to develop unnoticed because they are hidden behind cabinet doors.
Near the water heater
Check the inlet and outlet pipes on top of the water heater, the T&P relief valve and its discharge pipe, and any exposed piping in the utility area. Dissimilar metal connections (copper to galvanized steel) near water heaters are especially prone to corrosion.
Garage and exterior walls
Pipes running through unheated garages or along exterior walls are vulnerable to freezing damage. Check for cracks, bulges, or signs of previous repairs (patches, tape, or clamps). These pipes should be insulated if they are not already.
Signs of Pipe Damage by Material
Different pipe materials show damage in different ways. Knowing what to look for on each type helps you assess severity accurately.
- Copper pipes: Look for green or blue-green patina (corrosion), pinholes (tiny green-ringed spots that may weep), dents or kinks from impact, and white calcium deposits at solder joints. Healthy copper has a uniform reddish-brown or dark brown appearance.
- Galvanized steel pipes: Look for white or orange rust deposits, flaking or scaling on the exterior, reduced pipe diameter (unscrew a fitting and look inside—heavy buildup narrows the bore), and rust-colored water when a faucet first runs.
- PVC and CPVC pipes: Look for cracks, especially near joints. Check for discoloration (yellow or brown staining may indicate chemical damage). Feel for soft or spongy areas that suggest the pipe wall has degraded. Check that glued joints are not separating.
- PEX tubing: Check for kinks that restrict flow, UV damage (PEX degrades in direct sunlight), and loose or leaking crimp or clamp connections. PEX should flex evenly without sharp bends.
Corrosion Warning Signs You Should Not Ignore
These signs indicate active corrosion that is likely to lead to a leak if not addressed:
- Green streaks or stains running down from a joint: Active pinhole leak or seeping solder joint on copper. This will worsen over time.
- Flaking or pitting on the pipe surface: The pipe wall is thinning. If you can push a fingernail into the pipe material, it is severely corroded.
- Bulging or blistering: Internal corrosion has weakened the pipe wall to the point where water pressure is pushing it outward. This pipe could burst.
- Dissimilar metal corrosion: Where copper meets galvanized steel without a dielectric union, you will see heavy white and green deposits. This electrolytic corrosion eats through the galvanized pipe aggressively.
- Previous repair clamps or tape: A pipe that has been clamped or taped before has already failed once. The underlying corrosion has not stopped. Plan for a permanent replacement.
Check Pipe Supports and Hangers
Pipes need proper support to prevent sagging, stress on joints, and water hammer. While you are inspecting pipe conditions, also check how they are mounted.
What Proper Support Looks Like
- Horizontal copper pipes: Should be supported every 6 to 8 feet. Copper is soft and will sag over long unsupported runs, stressing joints.
- Horizontal CPVC pipes: Need support every 3 to 4 feet because plastic sags more easily than metal, especially when carrying hot water.
- No metal-on-metal contact: Copper pipes should not rest directly on steel hangers or straps without a plastic or rubber isolator. Direct metal contact causes galvanic corrosion.
- No sagging sections: A pipe that sags between supports creates a low point where water sits inside the pipe. In drain lines, this causes slow drainage and buildup. In supply lines, it accelerates internal corrosion.
Pro Tips
- •Know your pipe materials: Before you start, identify what types of pipes your home has. Copper is reddish-brown. Galvanized steel is silver-gray and magnetic. PVC is white plastic. CPVC is off-white or cream. PEX is flexible and comes in red (hot), blue (cold), or white.
- •Check your home's age: If your house was built before 1960, it may still have original galvanized steel pipes that are well past their expected lifespan. Homes built between 1978 and 1995 may have polybutylene (gray, flexible plastic) pipes that are failure-prone and should be replaced.
- •Photograph everything: Take dated photos of any corrosion, stains, or damage you find. These serve as a baseline for comparison. If you check again in six months and the stain has grown, you know the problem is active and worsening.
- •Touch the pipes while water runs: With someone running hot water upstairs, feel the hot water pipes in your basement. You should feel warmth along the entire run. Cold spots may indicate sediment buildup or a partially blocked section restricting flow.
Frequently Asked Questions
What do green stains on copper pipes mean?
Green stains on copper pipes (called patina or verdigris) indicate oxidation and active corrosion. A thin, even green coating on the outside of copper is normal aging and generally not a concern. However, green stains concentrated around joints, solder connections, or in streaks below a fitting usually mean the pipe is leaking or has a pinhole that is seeping water. These areas should be repaired before the leak worsens.
How long do different types of plumbing pipes last?
Copper pipes typically last 50 to 70 years. Galvanized steel pipes last 20 to 50 years before corrosion reduces their interior diameter and causes leaks. PVC and CPVC plastic pipes can last 25 to 40 years. PEX tubing is expected to last 40 to 50 years. Brass fittings and pipes can last 40 to 70 years. If your home has galvanized pipes and is more than 40 years old, proactive replacement should be on your radar.
Should I worry about white buildup on my pipes?
White crusty deposits on pipes usually indicate mineral buildup from hard water or slow corrosion. On galvanized steel pipes, white deposits often mean zinc is leaching from the pipe coating as it corrodes from the inside out. On copper or brass fittings, white or light-green deposits around joints may indicate a slow leak that evaporates and leaves minerals behind. Scrape the deposit gently: if the pipe underneath looks pitted or thin, it needs repair or replacement.