A surprising number of homeowners have no idea what material their home's water supply lines are actually made of, which matters more than it might seem, since the answer predicts a lot about future leak risk, water quality, and whether repiping is worth planning for.
Galvanized Steel: The Oldest Common Material
Galvanized steel pipe, common in homes built before the 1960s and still found in some Kennesaw homes near the older parts of the city, is a steel pipe with a zinc coating meant to resist corrosion. That coating degrades over decades, and once it does, the steel underneath corrodes from the inside, gradually narrowing the pipe's interior diameter and eventually causing leaks. Galvanized pipe is magnetic and has a dull gray color, and it's typically past a reasonable service life by 40 to 50 years.
Why This History Matters Today
A 1995-built home is now roughly 30 years old, well within polybutylene's documented failure window, and a home built in the late 1980s is even further along. Homeowners buying or inheriting a property from this era who haven't had the pipe material confirmed are essentially carrying an unknown, and given how differently polybutylene fails compared to gradually corroding galvanized pipe, that unknown is worth resolving rather than waiting to discover it during a sudden failure.
Polybutylene: A Specific 1980s-1990s Risk
Polybutylene pipe, a gray plastic material used in some construction between the late 1970s and mid-1990s, seemed like a durable, inexpensive alternative to copper at the time. It later turned out that chlorine commonly used in municipal water treatment degrades polybutylene from the inside over years, making it brittle and prone to sudden failure at fittings, often with little warning. Homes built in this specific window are worth checking for this material, particularly since it doesn't always fail gradually the way galvanized pipe does.
A Quick Note on Lead Solder
Copper pipe installed before 1986 was sometimes joined with lead-based solder, which has since been banned for potable water applications due to health concerns. A home with copper pipe from that era, even if the pipe itself is in fine condition, is worth having tested if there's any uncertainty about the solder used, since this is a water quality question separate from the structural leak risk covered elsewhere in this guide.
What To Do If You Suspect Lead Solder
- Run the cold tap for 30 seconds before using water for drinking or cooking if the home hasn't been used for several hours, which flushes out water that's been sitting in contact with older solder.
- Use only cold water for drinking and cooking; hot water dissolves more lead from old solder than cold water does.
- Request a water test specifically for lead if the home was built or plumbed before 1986 and the solder type has never been confirmed.
Copper: The Long-Standing Standard
Copper pipe, the dominant material from the 1960s through the 2000s and still commonly used today, is durable and resistant to most forms of corrosion, generally lasting 50 years or more. Its main vulnerability in the Kennesaw area is physical: copper is rigid, and Cobb County's red clay soil movement can eventually stress a soldered joint enough to develop a pinhole leak, particularly in supply lines running under a slab foundation.
One Real Limitation of PEX Worth Knowing
PEX degrades with prolonged direct UV exposure, which means it isn't suitable for exterior runs left uncovered, unlike copper. This is rarely an issue in interior or properly covered installations, which describes nearly all residential plumbing, but it's worth knowing for anyone considering PEX for an exposed exterior application, where copper or a UV-rated conduit covering would be the more appropriate choice instead.
PEX: The Modern Standard
PEX, a flexible cross-linked polyethylene tubing that's become the standard for new construction and repiping projects since the 2000s, resists the corrosion issues of both galvanized steel and copper, and its flexibility actually helps it tolerate the region's soil movement better than a rigid pipe would. It's also faster and less expensive to install, since it requires fewer joints than copper.
| Material | Common Era | Typical Lifespan | Main Risk |
|---|---|---|---|
| Galvanized Steel | Pre-1960s | 40-50 years | Internal corrosion |
| Polybutylene | Late 1970s-mid 1990s | Variable, often shorter | Chlorine degradation, sudden failure |
| Copper | 1960s-2000s, still used | 50+ years | Joint stress from soil movement |
| PEX | 2000s-present | 40-50+ years | UV degradation if exposed outdoors |
What About CPVC?
CPVC, a rigid plastic pipe similar in appearance to standard PVC but rated for hot water use, saw some use as a copper alternative in the 1980s and 1990s, though less commonly than polybutylene in residential construction. It's generally more durable than polybutylene and doesn't share that material's chlorine-degradation failure pattern, but it is more brittle than PEX and can crack under physical stress or with age, particularly at threaded connections. It's less commonly encountered in Kennesaw homes than the four materials above, but worth mentioning for completeness if it turns up during an inspection.
How to Identify What's In Your Home
A visible section of pipe in a crawl space, basement, or utility closet is the easiest place to check. Galvanized pipe is dull gray and magnetic. Copper is a distinct reddish-orange color. Polybutylene is typically gray plastic tubing, often with a stamped manufacturer code. PEX is usually red, blue, or white flexible tubing. If no pipe is visibly accessible, a plumber can typically identify the material from a fixture supply line or during any service visit.
Not sure what's running through your home's walls?
☎ (770) 214-4545If your home turns out to have galvanized or polybutylene pipe, the repiping and whole-home pipe replacement page covers real cost ranges and what the process actually involves. A single isolated leak rather than a sitewide material issue is more likely covered on the leak detection page. Powder Springs' historic downtown core has a similar concentration of older pipe materials as parts of Kennesaw.