Plumbing Piping in Homes
When buying a home, it’s important to understand what type of plumbing piping was used. In some cases, the wrong type of piping can lead to significant repair costs down the road. I’ve seen homeowners replace polybutylene piping, only to later discover that the older PEX they installed also created insurance headaches. Replacing your home’s piping once is expensive — having to do it twice is even worse.
Over the years, homes have used many different types of plumbing piping, including lead, cast iron, galvanized steel, copper, ABS, PVC, polybutylene, CPVC, and PEX. Each material has its own strengths, weaknesses, and lifespan. Below, I’ll walk you through the most common types, starting with newer materials and working backward.
Newer Plumbing Piping
Today, the most common piping materials used in new construction are PEX, PVC, and CPVC. Copper is still used, but it requires more skill to install properly, and quality copper workers have become harder to find in mass-produced homes.
PEX Plumbing Piping
Cross-linked polyethylene (PEX) was invented in Germany in 1968 and introduced to the United States around 1980, initially for radiant floor heating. It didn’t become widely used for domestic water lines until the late 1990s, and its popularity exploded in the 2000s.
Early PEX systems had significant problems with brass crimp and clamp fittings. The zinc in some of these brass fittings would leach out over time (a process called dezincification), leading to leaks and failures. This resulted in class action lawsuits, most notably against Kitec and, to a lesser extent, some Zurn products in the 2000s and early 2010s.
After these issues, manufacturers improved the fittings around 2010, switching to better-quality brass and plastic options. Newer PEX systems using these updated fittings have performed much better. Most manufacturers now rate PEX at a 50-year life expectancy when installed with modern fittings.
However, many insurance companies remain cautious about PEX installed before 2005–2010. If you’re buying a home with older PEX, make sure you understand your insurance company’s position on it.
PVC Plumbing Piping
PVC (Polyvinyl Chloride) became popular in the 1960s and 1970s, mainly for drain, waste, and vent lines. It was a major improvement over cast iron because it was lighter, cheaper, and much faster to install. A plumber could often install PVC drainage systems 5–10 times faster than cast iron.
PVC works very well when used correctly. It should never be installed where it will be exposed to direct sunlight, as UV rays will degrade it over time. Since most sanitary systems are gravity drains (not under pressure), failures are relatively rare. When problems do occur, they’re usually caused by physical damage or poorly glued joints.
CPVC Piping
CPVC (Chlorinated Polyvinyl Chloride) is used for pressurized hot and cold water lines. It was first developed in the late 1950s and became common in homes during the 1980s.
CPVC has had its share of issues. It can become brittle when exposed to certain chemicals (such as some fire caulks, spray foams, or high chlorine levels), which can lead to cracking. These problems resulted in some lawsuits, particularly in the 1980s and 1990s. Newer CPVC formulations (generally from 1991 onward) are significantly more resistant to these issues.
Manufacturers typically rate CPVC at 50–70 years, though real-world lifespan depends heavily on water quality, temperature, and installation quality.
Older Plumbing Piping
Lead Piping
Lead piping was once commonly used for drainage and sanitary lines. Because it wasn’t under pressure, it rarely failed structurally. However, lead can leach into drinking water and pose serious health risks. The use of lead piping in new construction was banned federally in 1986.
Cast Iron Piping
Cast iron was the standard drainage pipe for over 100 years. It was gradually replaced by PVC in the 1970s and 1980s because PVC was cheaper and easier to install. Cast iron tends to corrode from the inside, especially at the top of horizontal runs due to hydrogen sulfide gas from waste. Many older homes still have cast iron that remains serviceable. If your home has cast iron, it’s worth having it inspected by a qualified plumber.
Galvanized Piping
Galvanized steel plumbing piping was widely used from the 1930s through the 1970s. It typically lasts 30–50 years. Many homes built in the 1970s now have galvanized piping that is well past its expected lifespan. Over time, galvanized pipe rusts from the inside, which can restrict water flow and eventually cause leaks. Many insurance companies are hesitant to insure homes with active galvanized piping.
Copper Piping
Copper plumbing has long been considered a premium material for water lines. It’s durable, corrosion-resistant, and can last 50–70 years or more. Copper is still used today, especially in higher-end homes, but it has become less common in production housing due to higher material and labor costs. When properly installed, older copper piping is generally a good sign in a home.
ABS Piping
ABS (Acrylonitrile Butadiene Styrene) is primarily used for drain, waste, and vent lines. It has been in use since the 1950s and remains common in manufactured homes. It’s lightweight, easy to glue, and less expensive than cast iron. Failures are relatively uncommon when properly installed.
Polybutylene Piping
Poly Piping was used extensively from the mid-1970s through the mid-1990s. It was later discovered that chlorine in municipal water could cause the pipe to become brittle and crack, especially at the joints. Failures often resulted in sudden, high-volume leaks inside the home. A major class action lawsuit in the 1990s resulted in a multi-billion dollar settlement. If you own or are buying a home with polybutylene piping, most experts recommend replacing it.
So, What Piping Is Best?
Based on what I see during inspections, PEX and CPVC plumbing piping (with modern fittings) and PVC plumbing for drainage currently have the fewest problems in homes built after 2005. Copper remains an excellent material when installed correctly by skilled tradespeople. However, with the current shortage of experienced copper plumbers, I generally recommend PEX or CPVC for most homeowners unless you have a trusted contractor who specializes in copper work.
Water Heaters
Water heaters in Florida typically last only 12 to 18 years due to our high mineral content in the water. Sediment builds up quickly at the bottom of the tank, which reduces efficiency and eventually causes the tank to rust from the inside out.
Leaking water heaters can be especially problematic in slab homes, as water can run under the concrete and cause hidden damage. Temperature and pressure relief (T&P) valves should be tested periodically, as a failed valve can create a dangerous situation. Many older homes still have water heaters that are not up to current code standards.