All pipes are not created equal; know what yours are made of

Through the years, several types of piping have been used for supply pipes in homes in Georgia and the Southeast. Supply pipes are those that bring water from the street into the house and then to your plumbing fixtures —- sinks, water closets, tubs, etc. Since some of these materials have experienced failures of one type or another, it is a good idea to know what type of piping you have in your house and how to care for it.

Galvanized steel pipes

Galvanized piping is manufactured by applying a coat of zinc to steel pipe. The process typically used is “hot dipping.” This type of piping was installed through the 1940s and has a 30- to 40-year life expectancy.

Despite having reached the end of this life expectancy, some galvanized steel piping is still functioning adequately today. Galvanized steel pipe is rigid, silver in color and is connected by threaded fittings.

As the pipe ages, two things occur. The interior of the pipe corrodes and builds up deposits of minerals and rust. This build-up of minerals effectively reduces the interior size of the pipe, somewhat like arterial sclerosis in human arteries. The reduced pipe size results in a reduction of water flow (pressure) as well as rusty water if fixtures remain unused for a period of time.

The other effect of age on galvanized piping is rusting. The pipe rusts through at the threaded joints and even in the middle of pipe sections. This rusting can result in leaks. Both of these conditions are good reasons for replacing your galvanized pipes.

If you still have some galvanized steel pipes in your home, the best method to ensure against leaks is a visual examination. Once a year, check the pipes, especially the joints, for visible rusting or active leaking. If your house is constructed on a crawl space, this unpleasant task may require some crawling. If you are not the crawling type, you may choose to hire a licensed plumber or certified home inspector to check the piping for you.

Copper piping

Copper pipes are probably the most common type in metro Atlanta. The piping is rigid, the color of a penny and is joined by solder, or “sweating” of the joints.

Except in rural areas where the minerals in well water can cause corrosion of the copper, this type of piping performs well. Copper has been used since the 1950s, and its life expectancy may be as high as 60 years.

When inspecting houses, I see very few problems with copper piping. But mention should be made that at least through the 1970s, leaded solder was often used in the pipe joints, and lead can be toxic to humans.

Despite its good performance history, it is still a good idea to perform a visual inspection of your copper piping once a year for leaks.

Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC)

PVC and CPVC are rigid plastic pipes. The piping is joined with glue. PVC is white and not rated for use with hot water. CPVC is a more yellowish color and is rated for hot water use. For this reason, PVC is rarely used for interior piping. It is simply easier to use CPVC and not worry about distinguishing between hot and cold lines.

The use of PVC and CPVC started in the 1970s and, as with copper, PVC and CPVC perform well. Most problems encountered with PVC and CPVC piping appear to result from improper installation.

Polybutylene

Polybutylene piping is a flexible plastic pipe. The pipe is joined to its fittings by copper or aluminum crimp rings. The fittings (elbows, T’s, etc.) are either acetal plastic or copper.

The piping from the street to the house may be black, gray or blue. Blue is the most common color for the main service pipe and is a sky blue. The interior piping is most commonly gray.

Polybutylene was installed in thousands of homes from the late 1970s to the middle 1990s. Leaking problems with polybutylene have resulted in class-action lawsuits against the manufacturer of the plastic material.

If you have or suspect that you have polybutylene in your home, additional information about the material and the lawsuits can be obtained by calling 1-800-876-4698 or by typing the word “polybutylene” into your computer’s Internet search engine. Of all the types of supply piping, it is most important to perform a yearly inspection on polybutylene.

Polyethylene and PEX

A more recent arrival to the Georgia market is polyethylene piping. Polyethylene piping is a flexible pipe. The pipe from the street to the house is typically black or blue. (The blue is darker than the blue found in polybutylene pipes).

Cross-linked polyethylene, or PEX, piping is used for interior piping. As with polybutylene, the joints in PEX are copper held together with crimp rings. Depending upon the manufacturer, PEX can be clear, blue or red. The blue is typically used for the cold water and the red for the hot water.

So far, no serious problems have been encountered with the performance of this material. Except for the main service pipe from the street, polyethylene’s similarity to polybutylene is making it slow to catch on. If you have polyethylene piping in your home, chances are that your home is relatively new, and yearly inspections may not be so important.

Do you have a home repair question? Send e-mail to Ask the Inspector at homestyle@ajc.com.

homestyle@ajc.com