Plumbing

• How can you tell whether your water service pipe is made of copper, steel, lead or plastic?

  • Simply scrape the pipe material at the wall where the pipe enters the house. Copper is relatively soft and has a copper penny color. Galvanized steel is hard and has a silver-gray color. Lead is fairly soft. You will only see this type of service piping in homes that are about 100 years old. The joint where the lead has been sweated to the supply piping looks like a bulb or a short section of expanded pipe. It has a gray color.
  • Plastic piping will have a metal clamp where it joins the supply piping. Plastic service pipe is generally tan and white in color.
  • Learn more about plumbing pipe.
  
  
• How can you tell if poor water pressure is caused by problems with the supply piping or the service piping?
  • Consistently poor water pressure indicates that there is a problem with the supply piping (or the main source of water).
  • Water pressure that is acceptable for one or two seconds, then diminishes, indicates that there is a problem with the service piping that comes from the street to the house.
  • The reason for this is different pipe sizes. The service pipe is typically larger than the supply piping. If the supply piping is corroded or restricted, water will exhibit a consistently weak pressure. On the contrary, if the supply piping is good and the service pipe is corroded or restricted, the supply piping will fill and provide good volume for only a second or two, because the corroded service pipe will not be able to keep the supply piping filled.
  • Learn more about plumbing.
  
  
• How can you determine the condition of failing steel supply piping  before the water pressure becomes poor?
  • Look for small roundish rust warts or growths on the outside of the piping. Rust warts are failures that start from the inside of the pipe and come through the surface of the pipe. They typically do not leak immediately, but will usually start leaking within one year.
  • Learn more about steel piping.
  
  
• How can you tell when the well water is deteriorating the copper piping simply by looking at the house?
  • Look around the drains of the sinks and the tubs. If you see green patina stains in these plumbing fixtures, then it is a good indication that the well water is acidic and that the copper is being deteriorated. In extreme situations, round green stains can be seen on the horizontal runs of the pipes. These are failures, and will start leaking with a small spray of water. The solution is to test the water and install a neutralizing system to raise the water’s pH level.
  • Note: Brown-orange stains indicate excessive minerals in the water. Conditioning equipment is strongly recommended if this is the case.
  • Learn more about copper piping.

• How long does cast iron soil pipe last and where will the first failure typically occur?
  • Cast iron soil or drain pipe will generally be dependable for 60+ years. The first failures usually occur in the horizontal section of pipe, at about 8'–20' past or below the vertical vent pipe.  This failure develops on the top of the pipe. The reasons for the failure in the top of the pipe and at this specific location are:
  • The acids produced by the human digestive system (aka methane gas) deteriorates the top interior portion of the pipe. The bottom has moisture and a small amount of solids, and the acid doesn’t have the same impact.
  • The horizontal pipe is installed at a 1/8''–1/4'' slope towards the sewer in the street. The slope is necessary to provide fall that will allow gravity to drain the waste and to allow the liquid waste to mix with the solid waste so that both will exit the pipe. If there is too much slope in the pipe, the liquids will not adequately mix with the solids. The reduced friction will cause the liquid to drain quickly and cause the solids to lay in the bottom of the pipe. The solids will not clog or stop the flow, however, they will allow the acids to accumulate in one area and deteriorate the top of the pipe.
  • When waste drops in the vertical vent pipe from a bathroom, it will rush through the first 8' or so of the horizontal pipe. At this point, the liquid waste still has momentum while the solids have started to slow. Turbulence in this 8'-20' area is what is what accelerates the deterioration process inside the top portion of the pipe.
  • Note: In some cases, the vertical section of pipe is the first to fail. This is due more to workmanship than acid deterioration. The vertical section of pipe can weigh 300–400 pounds, depending on the height. If it is not supported or hung properly, the stresses and natural deterioration may cause failure in 60 or so years.

If you are a client and your question is not answered above, click here to Ask the Inspector.