Sewer lines have been used all over the world for centuries but have evolved a lot over the past few hundred years. Until the late 20th-century, most sewer pipes were made of wood, cast iron, fired clay, or fiber conduit. No matter what they were made of, sewer lines were built to last at least 50 years. In some places, clay and cast iron are still used in construction today, and many old sewer lines are still in service in buildings and under streets.
In the United States, wooden stave pipes were used for domestic water supply, irrigation, and sewer systems in the late 1800s and early 1900s. The pipes were made by lashing wooden planks together with a hoop in the same way that wooden barrels were made. Unlike clay or cast iron pipes, they were easy to transport. The staves and hoops could be hauled in a wagon and carried then assembled on site, making them especially popular in mountain regions and coastal canyons.
In California, redwood was the wood of choice because it was more resistant than other woods to insects, acids, weathering, and fungus. Redwood sewer and stormwater pipes were used all over California, even in Los Angeles. They stayed clean longer than clay or cast iron and didn’t expand or contract as much as iron when the temperature changed, so they were easier to maintain.
Clay is one of the oldest piping materials in the world and in some places, it’s still used today. In the United States, it was the material of choice from the 1880s to the 1900s. Like brick and tile, clay pipe is heavy and transporting it was difficult, so many towns had their own clay pipe plants. It’s made in 2 to 4-foot sections that fit together to form a joint.
Clay pipes are durable and resistant to corrosion, but over time, they can fail. Plant roots can work their way into the joints and cling to the outer surface of the pipe. The joints can also leak if a blockage causes pressure to build up. In some soils, they can shift over time and sag, come apart, or collapse.
Clay sewer pipes are made of clay and water which is formed, dried then baked in a kiln to vitrify it, forming a strong and durable material. Modern clay pipes can hold over 2,000-pounds of water pressure and, like their historic counterparts, are resistant to chemicals. In many places, they are encased in concrete to make them more resistant to root infiltration and ground shifting. They are also sometimes placed on a cement cradle for extra support.
Cast iron pipes have been used in the United States since the early 1800s. Initially, they were only used for water distribution. By the 1890s, cast iron sewer pipes were available in many areas and provided a highly reliable and durable alternative to clay or wood stave pipes. They are still used today.
Quality cast iron pipes can last 75 to 100-years but like clay pipes, they are heavy and difficult to transport. Installing them was labor intensive and they are difficult to maintain. Old cast iron pipes can vary in thickness and quality. They are resistant to the elements but can be damaged shifting soils, tree roots, and chemicals used inside the home.
Fiber Conduit (Orangeburg)
Fiber conduit sewer pipes, commonly called Orangeburg pipes, were used from the late 1870s to the 1970s. They were made with layers of fibers from wood pulp and pitch. During WWII, metal was scarce and they were cheap, easy to cut, and weighed less than clay pipes.
At the time, they were expected to last as long as 50 years but they have been known to fail in fewer than 10 years. In most places, it is no longer considered an acceptable material but some older buildings may still have Orangeburg sewer pipes. Since they are essentially made of fibers, they can warp, collapse and tree roots invade them easily.
Plastic (ABS, PVC)
In the late 1960s and early 1970s, plastic sewer pipes became the best choice for new sewer lines and repair. Plastic is easy to install, cheap and easy to transport. Because they fit tighter than cast iron or clay pipes, tree roots rarely get into the joints. ABS and PVC pipes are also longer and have fewer joints so they are less prone to leakage.
Today, plastic sewer pipes are commonly used in drain vent pipe systems and sewer systems. They are resistant to acids, alkalis, and salts and are used both below and above ground. ABS is easier to install than PVC but it can deform if exposed to a lot of sunlight so some localities require ABS pipes to either contain pigments to protect it from UVs or require it to be painted with latex paint.
Sewer lines have been around a long time but have changed significantly over the past hundred years. All sewer pipes were built to be strong and durable, but some last longer than others. Orangeburg pipes were meant to last 50 years, but break down quickly and should be replaced right away. Some wood stave pipes have stood the test of time but they are rare and nearly all have been replaced. PVC pipes are common today and can last well over 100 years, while cast iron is still used and lasts 75-100 years. In the right conditions, clay can last for 50 to 60 years and is still used today.