A sewer camera inspection is the best information available about a buried pipe, and it is still a picture of one surface taken from the inside. An honest inspector will say what the footage shows and will decline to say more, and a customer who understands why will ask better questions.
Quick answer: the footage cannot tell you how thick the remaining pipe wall is, what the soil outside the pipe is doing, exactly how deep the pipe is, how long a defect will take to fail, what lies beyond a blockage the camera could not pass, whether a crack leaks, or the cause of a sewer smell in the house. It can tell you what the inside looks like today, where, and what that usually means.
Wall thickness
Cast iron corrodes from the inside and the camera sees the rough surface, but it cannot measure how much metal is left behind it. A pipe that looks heavily scaled may have plenty of wall; one that looks smooth may be paper thin at the bottom. Only channeling, where the bottom is gone, is visible. Everything else is inference from age and appearance.
What is outside the pipe
Voids, washed-out bedding, soil pressure, a water main leaking next to the sewer, a root ball pressing on a joint: the camera sees none of it. It sees the results, an offset or a crack, after they happen. See what a camera cannot detect.
Exact depth
The camera reports distance along the pipe. Depth comes from the sonde and receiver, which estimate it, and from excavation, which confirms it. A report that states a depth without a locate has guessed from the slope.
How long it will last
An inspector can say that a joint is offset half an inch and that roots are entering it. They cannot say whether it will back up next month or in ten years. The pipe does not carry a schedule, and anyone who gives a confident date is selling something. What the inspector can say is what usually happens to that defect in that material, and whether it is getting worse by comparison to earlier footage.
What lies beyond a blockage
When the camera stops at roots, a collapse or standing water, the pipe beyond is unknown. A report should state clearly where the camera stopped and that the remainder was not inspected. Clearing the blockage and re-inspecting is the only way to know. See inspecting a line full of water.
Whether a crack leaks
A crack is visible; whether water passes through it is not, unless groundwater is seen entering. A line can have cracks that are sealed by soil and a joint that looks sound and leaks. Exfiltration is only proven by a pressure or dye test.
The cause of a smell
Sewer gas in the house comes from a dry trap, a failed vent, a cracked stack inside a wall or a broken drain under a slab far more often than from the lateral. The lateral camera cannot see any of those. See sewer gas and camera work.
Material, sometimes
Clay, cast iron and PVC are usually recognisable. Orangeburg, transite and some concrete pipe are confused with each other and with heavily scaled iron under poor light. An inspector who says the material is uncertain is being accurate.
Whether the line meets code
Slope, bedding, pipe class and connection method are code matters that the inside of the pipe does not show. A camera can show a belly that suggests a slope problem; it cannot measure the grade.
What the inspector can tell you
The material as far as it is recognisable. The length to the main. Every visible defect, its position and its severity on the inside surface. Where water stands and how much. Whether roots, grease or scale are present and how much of the bore they take. What those findings usually mean for that material and age. Whether a repair is likely, and of what kind. That is a great deal, and it is the basis of every decision about the line; it is simply not everything. See inspection limitations every customer should know.
Questions worth asking anyway
The limits above do not make the inspector useless on those subjects; they make their answers opinions rather than findings, and a good inspector will frame them that way. Ask what they would do if it were their house. Ask what they have seen happen to pipes in this condition in this neighbourhood, because local soil, local tree species and local pipe suppliers produce local patterns that an experienced inspector knows. Ask whether the defect is likely to be made worse by a cable or a jet, which matters before any cleaning is ordered. Ask which findings would need a locate before any repair quote is meaningful. The answers are experience rather than evidence, but experience is what the customer is paying for alongside the footage, and an inspector who separates the two is the one to trust.
Common questions
Can the inspector tell me how many years the pipe has left?
No. They can tell you its condition today and what usually happens next to that condition.
Why did the report say “not inspected beyond 54 feet”?
Because the camera could not pass that point. The pipe beyond is unknown and the report is right to say so.
Can a camera find the source of a sewer smell?
Rarely. Smells usually come from the house plumbing, not the lateral.
Related guides
See how to interpret footage, why inspections miss problems, and sewer camera monitors.