How long does cast iron pipe last?

The average lifespan of cast iron drain/sewer pipe is 50 to 70 years, with an average of 60 years. It is easily recognized by the thickened female “hub” at each pipe segment connection. Rust eventually eats through cast iron, primarily from the inside out, as shown in the photo below. Because corrosion is accelerated by moisture, pipe with light effluent flow and installed in a dry environment can survive 20 to 30 years longer, and cast iron in an extremely humid, wet environment can sometimes fail as soon as 40 years. Cast iron began to be replaced by plastic PVC and ABS plastic pipe in the mid 1970s, and has not been used for new construction since the 1980s.

    Here’s a graph comparing the life expectancy of cast iron to other types of pipe used in residential plumbing.
    Go to our blog post What is the average lifespan of the parts of a house? for rating of other house components. 

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Field Guide for Home Inspectors, a quick reference for finding the age of 154 brands of HVAC systems, water heaters, and electrical panels, plus 210 code standards for site-built and manufactured homes, and the life expectancy rating of 195 home components. Available at amazon.com for $19.95.
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Here’s links to a collection of our other blog posts about PLUMBING PIPES:

ABS Pipe

• What is the average life expectancy of ABS pipe?

• What is the difference between PVC and ABS plumbing pipe?

Cast Iron Pipe 

• How can I tell if I have cast iron pipes in my house? 

Copper Pipe 

• What is the average life expectancy of copper pipe?

• Should I use a dielectric union or brass nipple to connect copper tubing and galvanized steel pipe?

• What problems are caused by connecting copper pipe/tubing directly to galvanized steel pipe?  

CPVC Pipe 

• What is the average life expectancy of CPVC pipe?

• Can you connect CPVC pipe directly to a gas water heater?   

Galvanized Steel Pipe 

• What is the average life expectancy of galvanized steel pipe?

• Why is old galvanized steel water pipe a problem for homebuyers?

• What is a galvanized nipple? 

• Should I buy a house with galvanized steel water pipes? 

• Can galvanized steel pipe still be used for new water lines in a house?  

Orangeburg (bituminous fiber) Pipe 

• What is the average life expectancy of Orangeburg (bituminous fiber) pipe? 

• Why is Orangeburg sewer pipe a problem and how do I know if I have it?

PEX Pipe

• What is the average life expectancy of PEX pipe? 

• Can PEX pipe be installed outside?  

• Is PEX pipe freeze resistant?

PB (Polybutylene) Pipe 

• What does polybutylene pipe look like? Why is it a problem? 

• Does a "QEST" brand mark on pipe mean that it is polybutylene (PB)?

PVC Pipe 

• What is the average life expectancy of PVC pipe? 

• Why is sunlight exposure bad for PVC pipe? 

• Why can't PVC be used for water pipe inside a house? 

• What is the difference between green and white sewer drain pipes? 

Commonly Used Pipes By Decade

• What type water supply and drain (DWV) pipes were commonly used for 1950s residential plumbing?

• What type water supply and drain (DWV) pipes were commonly used for 1960s residential plumbing? 

• What type water supply and drain (DWV) pipes were commonly used for 1970s residential plumbing? 

• What type water supply and drain (DWV) pipes were commonly used for 1980s residential plumbing? 

• What type water supply and drain (DWV) pipes were commonly used for 1990s residential plumbing?

• What type of water supply and drain (DWV) pipes were commonly used in the 2000s? 

• What type of water supply and drain (DWV) pipes are commonly used today?

    Visit our LIFE EXPECTANCY and PLUMBING pages for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.