Most plumbing consists of pipes made from 6 different types of materials, clay, cast iron, Orangeburg, PVC, and ABS. Many plumbing systems use a combination of 2 or more of these pipes with a single house or building. Under most circumstances, you would not know exactly what type of pipe you have until you have a problem that requires it to be dug up. Having a scope inspection can help you understand exactly what type of sewer piping you have and can better assist in knowing what kind of maintenance schedule would be best. Many times, the time of the pipe is dependent on the age of your home or building.
Older homes typically built before the 1950s may have clay, cast iron, or Orangeburg pipes unless they have been retrofitted to newer materials such as PVC, ABS, or SDR35. Newer homes tend to have SDR35, PVC, or ABS.
What are the different types?
PVC – PVC pipe is white plastic piping with smooth interiors and exteriors. The smooth exterior of this pipe helps (but not entirely prevents) tree roots from anchoring to the pipe. PVC is more flexible than ABS.
ABS – ABS pipe is similar to PVC except that it is black. ABS pipe is stronger than PVC. Like PVC, it also has a smooth interior and exterior, inhibiting tree root anchoring to the pipe.
SDR35 – SDR35 is a type of PVC pipe that is only used in sewer and storm draining applications. It is green. It is not used for pressurized lines. It is a bit more flexible than standard PVC and is easy to connect to other types of piping. This type of pipe is common to see as a transition from the house to the mainline.
Cast-Iron – Cast Iron is common in older homes and is still used today. Cast-Iron is incredibly strong and can withstand over 2 tons of pressure, but it is very heavy to work with. Cast-Iron is nonflammable and will not melt in a fire.
Clay – Clay pipe is still used today, but it is very heavy and difficult to cut. One benefit to clay pipe is that it is very resistant to chemical degradation. Clay is porous and tens to attract tree roots, which can cause it to crack.
Orangeburg – Orangeburg is no longer used. Its life span is about 50 years, so it’s rarely seen these days. If this type of pipe is found in your home, it is recommended that it be replaced, even if you are not having any issues with it. Orangeburg is a fiber pipe that is made from wood fibers bound with adhesive and coal tar. It was used because it’s lightweight and easy to cut.