The History of Sewer Pipes in Alberta

Sewer backups are one of the most unpleasant plumbing problems a homeowner can experience. A sewer backup occurs when the main sewer line becomes blocked and wastewater flows back into the home through the lowest drain, often a basement floor drain, toilet, or shower.

In many cases, sewer problems are related to aging or failing underground pipes. Understanding what type of sewer pipe your home has can help you better understand potential risks and maintenance needs.

This guide explains the common sewer pipe materials used in Alberta over the past century and the typical issues associated with each one.

Common Sewer Line Problems

Sewer line issues often occur because older pipes deteriorate or shift over time. Some of the most common problems include:

• Pipe bellies: A section of pipe sags and collects waste.
• Root intrusion: Tree roots enter through cracks or joints.
• Pipe collapse: Structural failure prevents wastewater from flowing.
• Pipe misalignment: Sections shift and create leaks or blockages.

A sewer camera inspection is one of the best ways to evaluate the condition of underground sewer pipes. If you are buying a home, scheduling a sewer camera inspection during the inspection stage is highly recommended.

Early 1900s to 1970s: Clay (Terracotta) Sewer Pipes

Clay sewer pipes were widely used from the early 1900s until the 1970s. Clay was a popular choice because it does not rust and can withstand significant downward pressure from soil.

However, clay pipes are brittle and can crack during transport or installation. Over time, the joints between clay pipes often deteriorate, allowing roots to enter and cause blockages.

Clay pipes typically last about 50 to 60 years. Eventually they may crack, crumble, or collapse.

Early 1900s to 1970s: Cast Iron Sewer Pipes

Cast iron was another commonly used sewer pipe material until the 1970s. Cast iron pipes are strong, but they gradually corrode over time.

Cast iron pipes often rust from the inside out, creating rough interior surfaces where debris can collect. This buildup can lead to clogs and restricted wastewater flow.

The joints in cast iron pipes were often sealed using a bell-and-spigot design. As those seals deteriorate, the pipes can begin to leak and allow root intrusion.

1940s to 1960s: Orangeburg (No-Corrode) Pipe

Orangeburg pipe, sometimes called No-Corrode pipe or black pipe, was made from wood fibers bonded together with coal tar. It became popular during the post-war building boom when traditional materials like cast iron were in short supply.

While inexpensive, Orangeburg pipes were never particularly durable. Because the material contains organic fibers, it can break down over time. As the pipe deteriorates, it can lose its round shape, soften, and collapse.

Although it was originally expected to last up to 50 years, many Orangeburg sewer lines fail much earlier.

1940s to 1960s: Galvanized Steel Pipes

Galvanized steel pipes were also used in some plumbing systems during this period. These pipes were coated in zinc to slow corrosion.

Over time, the zinc coating wears away and the pipe begins to rust from the inside. This reduces the pipe’s structural strength and can lead to leaks or blockages.

Galvanized steel pipes typically have a lifespan of around 50 years.

1970s to Present: PVC and ABS Plastic Pipes

Since the 1970s, plastic sewer pipes have become the standard choice. PVC (polyvinyl chloride) and ABS (acrylonitrile-butadiene-styrene) are both widely used materials.

Plastic pipes have several advantages over older materials. They do not rust, rot, or corrode, and their smooth interior surfaces reduce the likelihood of clogs.

PVC Sewer Pipes

PVC pipes are durable and perform well in cold temperatures. They are typically stronger than ABS and widely used in modern plumbing systems.

ABS Sewer Pipes

ABS pipes are slightly more flexible than PVC and may be less likely to crack if the surrounding soil shifts.

Homes built during the 1970s may contain either PVC or ABS sewer pipes.

Potential Issues with Plastic Sewer Pipes

Although plastic pipes are generally more reliable than older materials, they are not immune to problems. Improperly sealed joints can allow leaks and root intrusion.

Another common issue is a pipe belly. This occurs when the pipe sags because the surrounding soil no longer supports it properly. When this happens, waste can collect in the low section of the pipe and eventually create a blockage.

Ground shifting or improper installation can both contribute to pipe bellies.

Why Sewer Camera Inspections Are Important

Regardless of the material used, underground sewer pipes should occasionally be inspected to ensure they are functioning properly.

A sewer camera inspection can identify cracks, root intrusions, pipe bellies, and other problems before they cause a major sewer backup.

What Should You Do Next?

If you are concerned about the condition of your sewer pipes or want to understand what material your home uses, a professional inspection is a good place to start.

The Gentlemen Pros can help with professional plumbing services and sewer camera inspections to assess the condition of your underground pipes and recommend the best next steps.