Common Plumbing Material Defects – A Historical Perspective

Plumbing materials have changed through the years for the better becoming safer, cheaper, stronger, lighter and easier to install.  All of which adds up to make your home a better place to live. I thought I would devote a little time to discuss common plumbing defects associated with the material used relative to the time period it was installed. 

pipesLet’s begin by talking about lead.  Lead is toxic to human beings. But did you know that it was commonly used in your home’s water supply up to 1986 when the Environmental Protection Agency (EPA) finally banned lead plumbing components and lead solder from supply plumbing? Moreover, houses built up into the 1950’s may contain a lead service pipe between the street and the house. This is common in older communities where services were never upgraded. A lead service is characterized by its dull gray, often bent shape, malleability when scratched with a knife, lack of magnetic attraction, and bulbous connection joints since it is not threaded. A lead service entrance creates a possible health concern if lead is able to leach into the drinking water after it sits in the pipe for a while. It is recommended to run the water for a while if this is the case.  To me, that’s just not good enough.  I recommend having your water tested for lead to be certain.  Most big box home improvement stores will carry an at home, do-it-yourself test kit where you can easily test for lead in your homes water supply.

Galvanized supply pipes were common place for many years until polymers became popular in the late 1970’s and early 1980’s.  Galvanized pipes are steel pipes coated with a layer of zinc to resist corrosion. This zinc layer eventually wears away after 20-30 years depending on the amount of use and the water quality. Galvanized pipes rust from the inside out and will usually show indications at fixtures when the water is run after sitting in the pipes for a few days.  It’s   not a matter of if but when these pipes will corrode to the point of failure.

Cast iron is an iron alloy that was used for DWV (drain, waste, and vent) piping prior to the 1960’s. It was typically made in 3-inch or 4-inch diameters, with sections joined together at hubs sealed with a packing material and molten lead. Cast iron rusts from the inside out and may develop pinholes. Cast iron is known for splitting lengthwise along the seams.  If you smell sewer gas in your home and have cast iron DWV piping then chances are you have a split pipe inside of a wall that needs to be replaced.

Be aware of polybutylene (PB) pipe in older homes, as it has a history of failure. PB is a gray plastic water supply line pipe that was developed in the 1970’s and promoted as the pipe of the future, due to its low cost and ease of installation over copper. In the 1980’s structures with PB started reporting leaks, and it was noticed that the interior walls of the pipes and fittings were breaking down and flaking apart. It was determined that PB is susceptible to corrosion when it comes into contact with chlorinated water, resulting in breakage and splitting. Some PB installations are fine and have no problems, but it is impossible to predict what might happen in the future. If your home has polybutylene supply pipes and you have noticed a change in the supply pressure then it’s time to call a plumber before extensive water damage occurs.

As you just learned, plumbing materials have changed through the years for the better.  A modern homes’ plumbing is made to last essentially forever but that was not always the case.  Old homes are great but they do need some modernizing in order to stand the test of time.  If your home has some of the plumbing materials mentioned above, then I urge you to inspect the visible pipes at least twice a year to determine their condition and protect against major plumbing leaks.