Things you Should Know about Galvanized Water Pipes
First of all and most importantly, you should know that galvanized water pipes are going to leak. It takes a while but is basically inevitable. Galvanized steel pipes corrode over time and eventually leak. In a worst case scenario one will burst – usually during a hard freeze.
Lead pipes were used for water supply in most homes in the U.S. until about the 1920’s when health concerns caused a switch to copper and galvanized pipes. In the 1950’s and 1960’s galvanized pipes were extremely common in home in the U.S. PVC & CPVC became popular in the late 1960’s but galvanized pipe were still used in some homes up into the early 1980’s.
Copper pipes are not uncommon and have been around for most of the 1900’s and is still used in some homes although it is pricey. Just about all builders in the U.S. have switched to PEX tubing which is durable and affordable and easier to install.
But back to Galvanized pipes; Houses built in the 1950’s through the 1960’s were likely built with it. Houses built in the 1970’s & 1980’s may have been built with it. It is still in use in many houses today but in every case it is at the end of its useful life span.
So how long does it last? On average it lasts 40 to 50 years. It depends on some variable factors mainly having to do with the quality of manufacture. It is made all over the globe and some countries have less stringent guidelines and controls on production than others. A lot of steel including galvanized pipe was imported during the 1960’s because it was cheaper. It was cheaper because it was of lower quality but a lot of it got used.
What happens to it? It corrodes. It corrodes from the inside out so it is very difficult to look at it and tell what condition it is in. Over time the galvanization (a zinc coating) wears away inside and the steel pipes begin to corrode.
As the corrosion builds up the inside diameter of the pipe gets smaller. This causes lower water pressure and you may also notice rusty colored water at fixtures that don’t get used as often. As the corrosion turns loose the particles that are sent down stream get hung up in the aerator screens at various faucets – again causing loss of water pressure.
Corrosion inside the pipe will eventually eat through the pipe and the pipe will begin to leak. This is usually just a slow leak which may not show much immediate damage. Sometimes these small leaks are “self-sealing” when more corrosion fills in the hole for a while. Eventually you will notice a brown water stain in the area or if you don’t notice it in time, the ceiling may fall in.
The worst case scenario happens in pipes that are weakened by heavy corrosion. When these pipes are exposed to freezing conditions they are likely to burst. Now, all at once you have a flood inside your home that can cause thousands of dollars’ worth of damage.
Can a home inspector determine the condition of galvanized pipes? Not really. In my area along the Texas gulf coast the pipes are often not visible except in a few places. We don’t have basements so the pipes are almost always in the attics and walls. We can see behind the walls. In the attic spaces pipes are often covered by insulation and not visible.
In some cases where there is not much insulation or the insulation has been disturbed the pipes may be visible to some degree. They can usually be seen at places like water heaters and under sink fittings and other stub outs for hose bibs and washer connections.
Even when they are visible it is difficult to tell how badly corroded they are. In some extreme cases it can be seen but this is not as easy to spot as you may think. Attic spaces are often difficult and sometimes unsafe to move around in. Some homes are designed is a manner that makes complete attic access virtually impossible. A good home inspector will at a minimum let you know in his report that galvanized water pipes are present.
So what is the bottom line? First remember that the average lifespan of galvanized pipe is 40 to 50 years. Some will make it to 60 years and some won’t make it to 40 years. How old is the house? What year is it now? A house built in 1965 has 56 year old pipes in 2021 when this was written. The bottom line is those old galvanized pipes need to be replaced.
To see some good photos of corroded galvanized pipe click here.
Posted: Jan 13, 2021
Posted by: Ed Fryday, ACI, CMI® | TREC License: #6932
Space City Inspections, LLC