What Does a Sewer Scope Find, and Is It Worth It on an Older Pittsburgh House?

By Aubre J. Stacknick, Global Real Estate Advisor, Piatt Sotheby's International Realty. Originally published on aubrestacknick.com.

A sewer scope is a camera inspection of the line that carries waste from the house to the street. On an older house it is usually worth it, because the line is buried, out of sight, and expensive to repair once you own it.

The sewer line is the one major system a regular home inspection cannot see. It runs under the lawn, the driveway, and sometimes the neighbor's yard, and it can be failing for years before anyone notices.

A camera on a flexible cable settles the question in about an hour.

Aubre J. Stacknick is a Global Real Estate Advisor with Piatt Sotheby's International Realty in Pittsburgh, PA, helping buyers and sellers across Western Pennsylvania see a home through a builder's eyes. The sewer line is the part of an older house buyers forget, and the part builders think about first.

What is a sewer scope?

A sewer scope is a video inspection of the lateral, the pipe that runs from your house to the municipal main or septic system. A technician feeds a waterproof camera on a flexible cable into the line through a cleanout, a pipe opening that is usually in the basement or near the foundation. The camera records what it sees as it travels.

You get a video and a written report. A good report notes the pipe material, the condition, the problems found, and where along the line they are.

What can a sewer scope find?

Most of what goes wrong in an old line is visible on camera.

• Roots. Tree roots enter through joints and cracks and grow into a mat that slows or blocks the line.
• Cracks and breaks. Older pipe, especially clay tile and cast iron, can crack or separate.
• Offsets and sags. A joint that has shifted, or a section that has sunk and holds water, called a belly.
• Corrosion and scale. Cast iron and steel rust from the inside and narrow the opening.
• Collapse. A section that has caved in and blocks the line.
• Pipe material and transitions. Where one kind of pipe joins another, and whether a repair was done properly.
• Blockages and grease. Buildup that can be cleaned, and the question of why it keeps coming back.

A scope does not tell you everything. It reads the line from the cleanout to the main. It cannot see outside the pipe, and it cannot predict what a root will do next year.

Why does the age of the house matter?

Houses built before the middle of the twentieth century often have the original sewer line, made from clay tile, cast iron, or a material called Orangeburg that was made from compressed fiber and tar. These materials can last a long time, and they can also fail. Each one has its own typical problems.

A newer house is not exempt. A line that was poorly bedded or backfilled can sag, and roots do not care how old the pipe is. Age raises the odds. It is not the only reason to look.

In an older Pittsburgh neighborhood, a mature tree between the house and the street is another reason. Roots search for water, and a joint is a source of water.

Who is responsible for the lateral?

That depends on where you are, so ask. In many municipalities the property owner is responsible for the lateral from the house to the main, which can include the part under the street. In others, the municipality or sewer authority takes responsibility for part of it. Some places have rules about replacing a lateral when a house is sold or when the line is repaired.

Do not assume. Ask your agent to find out what your municipality or sewer authority requires, and ask the seller whether any work has been done under a permit. A buyer who learns the rules after closing is a buyer who pays for the surprise.

When is a sewer scope most worth it?

Add a scope when any of these are true.

• The house is older and the line has never been replaced.
• There are mature trees between the house and the street.
• There is any history of a slow drain, a backup, or a floor drain that gurgles.
• The house has been vacant, or has a finished basement with a drain you cannot see.
• A renovation changed the plumbing, and you want to know the line can handle it.
• The seller cannot tell you the age of the line or whether it has been inspected.

For a house with a recent line and a seller who has the paperwork, a scope may be less urgent. I would still ask for the report.

When should you order the scope?

During your inspection period, alongside the general home inspection. Ordering after the period ends leaves you with a report and no leverage. A scope that finds a problem inside the window gives you choices: ask for a repair, negotiate a credit, or walk away.

Ask the inspector to give you the video, not just the summary. The video lets a plumber or a second inspector read the line without another visit.

What do you do if the scope finds a problem?

Match the answer to the problem.

• Roots or buildup. Often a cleaning. Ask what keeps happening and whether the line is otherwise sound.
• A single cracked or offset section. A spot repair may work. Get a written quote from a licensed plumber.
• A sagging line or widespread cracking. This is a larger conversation. A replacement is possible, and a trenchless method may avoid digging up the yard. Quotes vary, so get more than one.
• Collapse. A line that has collapsed needs replacement, and it should reshape your offer.

The goal is to price the problem before you own it. A scope can turn an unknown risk into a number you can negotiate.

Does a sewer scope matter if I am selling?

It can. A seller who orders a scope before listing knows what a buyer's inspector will find, and can fix small things first or price the house honestly. A clean report is a document you can hand a buyer. Be ready to disclose what the scope finds, because a known defect belongs in the property disclosure.

The common mistakes buyers make with sewer lines

• Assuming a home inspection covers the sewer line
• Ordering the scope after the inspection period has ended
• Accepting a verbal "the line is fine" from the seller
• Skipping the video and keeping only the summary
• Not asking who is responsible for the lateral

For more on spotting expensive problems before you buy, read How Can I Tell if a House Has Expensive Problems Before I Buy It?. If you are looking at an older home, What Should I Look For When Buying an Older Pittsburgh Home? covers the other systems. And on a house that has been updated, How Can You Tell If a Renovation Was Done Right Before You Buy? explains what a new kitchen can hide.

Common questions

If you are looking at an older house and want help deciding what to inspect and when, book a 30-minute call. Bring the address.