How a sewer camera inspection works, step by step

01 /What equipment does a sewer camera inspection use?

A residential sewer camera inspection uses a push camera system: a camera head, a reel of semi-rigid push cable, a monitor or recording unit, and usually a separate hand-held locator. The camera head is typically a sealed stainless or composite cylinder with a lens, a ring of LEDs and a small radio transmitter called a sonde. Behind the head sits a flexible spring so it can turn through bends in the pipe.

Many systems use a self-levelling image so the bottom of the pipe stays at the bottom of the screen. That matters because the water line is the operator's main reference for grade: if the picture rotates, it is harder to tell a sag from a camera roll.

The same principle scales in both directions. Municipal crews drive crawler cameras through mains from manholes and can send a lateral launch camera up a service connection; CCTV sewer inspection explains how that work differs from a house scope. At the other end, rental and consumer cameras let owners take a look themselves, with real limits described in renting a sewer camera.

02 /How does the technician get into the sewer line?

The technician gets into the line through the best available opening, in this order of preference: a cleanout on the main building drain, a pulled toilet, a roof vent, or a floor drain. The right entry point determines how much of the system can be seen.

If no usable cleanout exists, the report should say so. Adding a cleanout is often recommended afterward because it makes every future cleaning and inspection cheaper and less invasive. The cleanout and access notes in the glossary define each fitting, and sewer cleanouts and inspection points shows where to look for one and how a toilet-flange entry works.

03 /What happens during the inspection, step by step?

1. Pre-check and questions

   The technician asks about symptoms, backups, previous cleaning and renovations, and asks that no one runs water, flushes or starts laundry during the inspection.

2. Open the access point

   The cap is loosened slowly. If water is standing behind it, the line is backed up and may need to be relieved before a meaningful inspection is possible.

3. Zero the counter

   The distance counter is set to zero at a fixed reference point, usually the cleanout opening, and that reference is noted in the report.

4. Push to the main

   The operator feeds the camera steadily, pausing at every joint, transition and change in the pipe. Where the view is unclear, a small amount of water may be run from upstream to show flow.

5. Stop and record at each observation

   Defects are recorded with the distance and, on many systems, a text overlay or voice note. Better operators rotate or tilt the head to show the full circumference.

6. Locate key points from above

   At significant defects and at the end of the run, the operator uses a locator to find the sonde signal and marks the ground with paint or flags, noting estimated depth.

7. Identify the connection

   The camera ideally reaches the tie-in at the municipal main. The operator notes the connection type and any defect there.

8. Retrieve, clean up, reseal

   The camera is pulled back, cleaned, and the cap reinstalled or the toilet reset on a new wax ring.

9. Deliver video and report

   You should receive the recording and a written summary. See what a good report contains.

On a typical house with a usable cleanout, that whole sequence takes roughly 45 to 90 minutes. A toilet pull, a backed-up line or several branches add time; how long a sewer scope takes breaks down where the minutes go and when to expect the written report.

04 /How does the footage counter work, and how accurate is it?

The footage counter measures how much push cable has left the reel, shown in feet or metres on the screen. It is accurate enough to find a defect again, but it measures cable, not straight-line ground distance. Cable can coil in a large pipe, climb over debris or take a longer path through fittings, so the counter tends to read a little long over long runs.

That is why a counter reading is best paired with a surface locate. A report that says 'offset joint at 11.2 m' tells a repair crew roughly where to look; a paint mark in the lawn at that joint with an estimated depth tells them where to dig. Our locating and depth guide explains how that surface mark is made and how far to trust it.

05 /What can a sewer camera not see?

A sewer camera cannot see the outside of the pipe, the soil and bedding around it, or anything submerged in standing water or buried under debris. It records the inside surface of the pipe along one path. Knowing these limits is how you read a report fairly.

• Underwater sections — in a sag or behind a blockage, the lens goes under and the pipe wall disappears. The report should record the start and end of the underwater section.
• Behind heavy roots or grease — a root mass can hide a crack or a broken section beneath it until the pipe is cleaned.
• Voids around the pipe — a camera sometimes sees soil through a hole but cannot measure a void outside the pipe.
• Branches not entered — a single run from one cleanout may miss other branches, a second building drain or a storm connection.
• Flow and capacity — a camera shows condition, not whether the pipe is sized or sloped correctly along its whole length; a sag is inferred from water depth, not surveyed.
• Future behaviour — a clean video today does not predict root growth next summer.

If the camera stops short of the main, the reason and the distance should be stated plainly. That is a finding in its own right and usually leads to cleaning and a second pass.

06 /Should the line be cleaned before the camera goes in?

It depends on the purpose. For a purchase or a condition baseline, an inspection of the line as it is shows what the new owner inherits, including roots and buildup. For diagnosing a structural problem, cleaning first often reveals defects that roots or grease were hiding. Many contractors do both: a first pass to see the as-found condition, cleaning, then a second pass.

If a seller provides a video, ask whether it was recorded straight after cleaning. For cleaning methods and what they can do to fragile pipe, PipeCleaning.ca covers augers, jetting and descaling in depth.

07 /Safety during a sewer camera inspection

Most residential inspections are low risk, but the hazards are real. Sewer gas can contain hydrogen sulfide and methane. Opening a cleanout on a surcharged line can spray wastewater. Inspecting from a manhole or deep pit is confined-space work that requires training, gas testing and a rescue plan under provincial occupational health and safety rules.

The more common problems are small and happen at the access point: a toilet reset that seeps, a seized cleanout plug that cracks its fitting, or a cap left loose. They are covered, with the checks that prevent them, in can a sewer scope cause problems.

Once you understand the process, the next step is knowing what the finished product should look like. Read how to read sewer camera footage, or request an inspection quote.

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