What a Sewer Scope Actually Shows
A sewer scope is a camera inspection of the main sewer line running from your house to the municipal connection or septic tank. The plumber feeds a waterproof camera on a flexible cable through the line, recording video of the pipe's interior condition.
The camera reveals things you literally cannot see any other way:
- Root intrusion at pipe joints
- Cracks, breaks, and collapsed sections
- Bellied or sagging pipe that traps waste
- Offset joints where sections have shifted
- Pipe material and overall condition
- Blockages and buildup
Standard home inspections don't include underground sewer lines. I can run water and check for obvious drainage problems, but the pipe under your yard is invisible to me without a camera.
The $150 That Saved $12,000
My friend Greg almost skipped the sewer scope. The house was only 35 years old with PVC pipes. "It's not like it's got old clay pipes," he said. "PVC lasts forever."
I talked him into it anyway. The house was at the bottom of a hill, which meant the sewer line ran a long way to reach the street.
The camera found the problem 60 feet from the house. A section of pipe had bellied, probably from ground settling. Waste was collecting in the low spot instead of flowing to the street. The belly was holding water and debris. It wasn't causing backups yet, but the plumber said it was only a matter of time.
Repair quote: $6,800 for excavation and replacement of the damaged section. Plus another $5,200 if they found additional problems once they started digging.
Greg negotiated an $8,000 credit from the seller. He got the work done for $7,400. That sewer scope paid for itself 50 times over.
When I Recommend Sewer Scopes
Not every house needs a sewer scope. Here's my honest breakdown based on what I've seen.
Definitely Get One
Houses over 30 years old with original sewer lines. Clay pipe was common before the 1970s and is highly susceptible to root intrusion. Cast iron lines from this era may be corroding. Even early PVC can have joint problems from ground movement.
Any house with mature trees between the house and the street. Tree roots seek water. Sewer lines are full of water. You can predict what happens next. I've seen roots from trees 50 feet away work their way into sewer pipes.
Houses where drains throughout the home are slow. If it's just one fixture, that's a local clog. If the whole house drains slowly, the main line is restricted.
Houses with a history of sewer problems. Ask the seller. Check the disclosure. Look for past repair invoices. Previous backups suggest ongoing issues.
Probably Worth It
Houses 20-30 years old, especially if the sewer line material is unknown. This is the gray zone where problems are possible but not guaranteed. The $150-300 cost is cheap insurance.
Houses in areas with known soil movement issues. Expansive clay soils, hillside properties, and areas with high water tables can stress underground pipes.
Lower Priority
Houses under 15 years old with no drainage symptoms. Modern PVC sewer lines rarely have problems this young unless something went wrong during installation. I don't actively discourage inspection, but the odds of finding something significant are low.
That said, I've been surprised. A 10-year-old house in a new development had a sewer line that wasn't properly connected at the street. Waste was leaking into the ground. The smell hadn't reached the surface yet, but it would have. Sometimes even new houses have problems.
The Scope That Found Nothing
Not every sewer scope reveals disaster. My neighbor Christine got one on her 1985 ranch house. Sixty-year-old clay pipes running under a yard with two big oak trees.
The camera showed beautiful pipe. Some minor root hairs at joints, but nothing that would cause problems for years. The plumber actually commented on how good the line looked for its age.
Christine spent $175 for peace of mind. Some people would call that a waste. She calls it the best money she spent on the whole purchase.
"I would have wondered about those pipes forever," she told me. "Now I know they're fine. I can forget about it."
That's valid. Sometimes the value of an inspection is confirming that nothing is wrong.
What Problems Look Like on Camera
If you're present during a sewer scope, here's what you might see.
Root Intrusion
Roots appear as white or brown masses inside the pipe. Minor root hairs look like tiny threads. Major intrusion looks like the pipe is full of hair. In severe cases, roots form a solid mass that barely allows water through.
Root treatment (cutting or chemical) costs $200-500 and needs to be repeated periodically. Major root intrusion often means pipe replacement because the roots keep coming back through the damaged joints.
Bellied Pipe
A belly appears as a low section where water pools. The camera shows the water level rising and then dropping as it passes through the sagging area. Minor bellies might be monitored. Significant bellies that hold waste need repair.
Bellies typically require excavation and replacement of the affected section. Cost depends on depth and location: $3,000-10,000 is common.
Cracks and Breaks
Cracks appear as visible lines in the pipe wall. The camera might show soil or debris pushing through the crack. Complete breaks show a gap with soil visible.
Small cracks in otherwise solid pipe can sometimes be lined or sleeved. Major breaks need replacement.
Offset Joints
Offset joints occur when pipe sections shift out of alignment. The camera shows a step or lip where one section is higher than the next. This catches debris and paper, leading to clogs.
Severe offsets need repair. Minor offsets might be acceptable, especially in older clay or cast iron lines where some movement is expected.
The Real Cost Comparison
Here's the math that convinced me to recommend sewer scopes.
Sewer scope inspection: $100-400
Repair costs for common problems:
- Root cutting and treatment: $200-500
- Spot repair of damaged section: $1,500-4,000
- Full sewer line replacement (excavation): $5,000-15,000
- Full sewer line replacement (trenchless): $8,000-25,000
- Emergency backup cleanup and repair: $3,000-10,000 plus
Even the cheapest repair costs 10 times more than the inspection. And if the scope reveals a major problem, you can negotiate the cost into the purchase or walk away entirely.
My clients from that 1962 colonial would have been on the hook for $18,400 in sewer replacement. Instead, they spent $150 and bought a different house.
How to Get a Sewer Scope
Your home inspector may offer sewer scope service directly or have a plumber they work with. Many inspection companies add this as an optional service for $100-200 during the home inspection appointment.
You can also hire a plumber independently. Stand-alone sewer scope inspections typically cost $150-400 depending on your area and the company. Make sure they provide video footage you can keep.
Schedule the scope during your inspection contingency period. If problems are found, you need time to get repair quotes before your contingency expires.
What to Ask For
Request:
- Video recording of the entire inspection
- Written report describing findings
- Location marking if problems are found (so you know where to dig)
- Assessment of overall pipe condition and material
- Recommendations for repair if needed
Keep the video. If you buy the house and have problems later, the video documents the baseline condition.
The Bottom Line
I've been at inspections where the sewer scope was the most important $150 the buyer spent. I've also been at inspections where it confirmed everything was fine and people wondered if they wasted the money.
Both outcomes are valuable.
For houses over 25-30 years old, especially with mature trees, I recommend sewer scopes without hesitation. The risk-reward ratio is too favorable to skip. For newer houses with no symptoms, it's optional but still reasonable for peace of mind.
Underground pipes are the one major system you cannot evaluate any other way. A camera is the only tool that shows what's happening down there. For a few hundred dollars, you can know for certain whether you're buying a house with a ticking time bomb under the yard.
I've never had a client regret getting a sewer scope. I've had several regret skipping it.