To read sewer camera footage, watch three things in every frame: the distance counter, the water line at the bottom of the pipe, and the joints passing by. A steady thin water line means good grade. Water that deepens until the lens goes under means a sag. A ring that shifts off-centre is an offset joint. Anything hanging into the pipe is roots, debris or broken pipe.
- The water line is your level: its depth and shape tell you about slope and sags more reliably than the picture's angle.
- Joints arrive at a steady rhythm set by pipe length; a joint that looks different from its neighbours deserves a pause.
- Offsets show as a step or lip; separations show as a dark gap or visible soil.
- Lighting, lens distortion and a rolling camera head can make sound pipe look alarming; compare with the counter and the water line before deciding.
- Pause on anything that changes the circle: roots, cracks, holes, transitions and fittings.
01 /What should you look at first in sewer camera footage?
Look first at the on-screen distance counter, then the water line, then the joints. The counter tells you where you are. The water line tells you whether the pipe is flowing downhill properly. The joints tell you how the pipe was assembled and where it is most likely to fail. Everything else is detail against those three references.
- Confirm the start point
Note the counter at zero and what is visible: a cleanout fitting, a toilet flange, a floor drain.
- Find the water line
In a healthy lateral, a thin ribbon of water runs along the bottom. Watch its depth as the camera advances.
- Count joints
Older clay pipe typically comes in short lengths, so joints pass frequently; plastic pipe comes in longer lengths, so joints are fewer. A sudden change in joint spacing often marks a repair or material change.
- Pause at each change
Anything that alters the round, clean outline of the pipe — a ring, a lip, a dark line, a hanging object — is worth freezing and noting with the counter reading.
- Watch the end
The connection to the main looks like the pipe opening into a larger space or a tee. Note whether the camera reached it.
02 /What does the water level tell you?
The water level tells you about grade. A pipe with steady slope carries a shallow, consistent stream. Where the pipe dips (a sag or belly), water pools: the stream widens, deepens, and in a bad sag the camera lens goes completely underwater, then climbs back out as the pipe rises again.
| What you see | Likely meaning | How much it matters |
|---|---|---|
| Thin, steady stream along the bottom | Normal grade | Good sign |
| Stream widens gradually over a few metres, then returns | Shallow sag | Often tolerable; debris may settle; monitor |
| Lens partly under water for a long stretch | Significant sag | Settling solids, paper snags, freezing risk in shallow lines; get a repair opinion |
| Lens fully submerged, picture lost | Deep sag or downstream blockage | Cannot inspect that section; must clean or repair to know more |
| Water level rising along the whole run | Blockage downstream or a surcharged main | Stop and find the obstruction before judging the pipe |
| Pipe dry at a point that should be wet | Short upslope or a high spot | Usually a local rise before a sag; look downstream |
Water depth is often described as a percentage of pipe diameter. A sag that holds water to 10 or 20 per cent of the diameter over a short length is common and often left alone. Deeper standing water over a longer length tends to catch solids and is more likely to cause repeat blockages.
03 /What do joints look like, and when are they a problem?
A healthy joint looks like a thin ring where two pipe lengths meet, with the pipe walls lining up on both sides. A problem joint shows a step (offset), a gap (separation), roots, or a bead of material hanging from the ring.
| Appearance | Name | Typical concern |
|---|---|---|
| Thin even ring, walls aligned | Sound joint | None |
| Small step at one side of the ring | Minor offset | Low; note location |
| Pronounced lip the camera bumps over | Medium to large offset | Snag point; roots and paper catch; repair often recommended |
| Dark band or visible soil in the ring | Separated (open) joint | Soil and roots can enter; void risk |
| Strands or clumps growing from the ring | Root intrusion at joint | Grows back after cutting; see SewerRoots.ca |
| Hanging gasket or mortar | Displaced seal | Obstruction; joint no longer sealed |
An offset that drops at the bottom of the pipe (a step down at 6 o'clock in the direction of flow) is less troublesome than one that rises into the flow, because the rising lip catches solids. The report should say which way the step goes.
04 /How can you tell roots from debris or grease?
Roots usually enter at joints or cracks and look fibrous: fine hair-like strands, then thicker veins, then a dense mat or ball that moves slightly in the flow. Grease looks smooth, pale and waxy, often coating the upper walls or forming a ledge at the water line. Debris such as wipes, paper or construction material sits loosely in the flow and often moves when the camera nudges it.
- Roots — originate from a joint or crack, branch and spread, sometimes cover the full circumference.
- Grease (FOG) — smooth, cream to grey, builds up from the water line; common downstream of a kitchen.
- Scale and tuberculation — rough, rusty-orange or black nodules on cast iron walls.
- Settled debris — gravel, sand or broken pipe pieces sitting in the invert, often where a sag or break is nearby.
- Wipes and paper — pale, draped over roots or offsets; a sign of what is catching there.
05 /What do cracks, fractures, holes and collapses look like?
A crack appears as a thin dark line in the pipe wall with the wall still intact on both sides. A fracture is a crack that has visibly opened or shows the pipe pieces shifting. A hole or broken section shows a missing piece, often with soil behind it. A collapse is a loss of the pipe's round shape, with the camera unable to pass or passing through a much smaller opening.
| Defect | On screen | Typical next step |
|---|---|---|
| Crack (longitudinal, circumferential, multiple) | Fine dark line; wall intact | Monitor or include in a lining decision |
| Fracture | Opened line, visible edges | Repair opinion |
| Broken / missing piece | Chunk out of the wall, soil visible | Spot repair or replacement |
| Hole | Opening in the wall | Repair; risk of void around pipe |
| Deformed pipe | Circle flattened into an oval (plastic or fibre pipe) | Assess; severe deformation may not be lineable |
| Collapse | Pipe shape lost; passage blocked or nearly so | Excavated or trenchless replacement of the section |
For code-by-code explanations, open the inspection report decoder and search the term used in your report.
06 /What camera effects can fool you?
Camera effects that can fool an untrained viewer include wide-angle distortion, reflections, a rolling head and lighting changes. Before concluding that a pipe is broken, check whether the feature stays in the same place as the camera moves past it.
- Barrel distortion — the wide lens makes nearby walls bulge; a round pipe can look oval near the lens.
- Glare on water — bright reflections can look like holes or white debris.
- Head roll — if the image rotates, the water line moves to the side; a non-levelling head can make a straight pipe look twisted.
- Condensation or grease on the lens — a blurry patch that moves with the camera is on the lens, not the pipe.
- Fittings mistaken for defects — a wye or tee where a branch joins looks like a hole on one side; branch openings are round and smooth.
- Transitions — a change from clay to PVC shows as a change in colour and diameter, sometimes with a rubber coupling band. It is not a defect by itself.
If it moves with the camera, it is on the lens. If it stays with the pipe, it is in the pipe.
07 /What should you write down while watching?
Write down the counter reading, the clock position and a short description for every pause. Five columns are enough: distance, what, where around the pipe, size, and your question. That list is exactly what you need to compare against the written report and to ask a second company for an opinion.
| Distance | What | Clock position | Size / extent | Question |
|---|---|---|---|---|
| 4.1 m | Roots at joint | 10 to 2 | Fine strands | Maintenance only? |
| 8.4 m | Offset joint | 6 | Visible lip | Repair needed? |
| 10.2 to 13.0 m | Standing water | Invert | About 30 per cent of diameter | Sag repair worth it? |
Compare your notes with the report checklist, then read what to do after an inspection. If you have footage but no report, you can request a review or a fresh inspection.
Once your notes are complete, enter the distances and types in the Lateral Defect Map. Seeing the findings drawn from the access point to the main makes patterns obvious: roots at evenly spaced joints look very different from one broken section beside the foundation.
FAQQuestions people ask
Why is there always water in the bottom of my sewer pipe?
A thin stream is normal because the pipe carries wastewater and drains slowly between uses. Concern starts when the water gets deep or stays deep over a long section, which suggests a sag or a blockage downstream.
What does it mean when the camera goes underwater?
The lens has entered standing water, usually in a sag or behind a downstream blockage. The pipe wall in that stretch cannot be seen, so the report should list the start and end distances of the submerged section.
How do I tell a joint from a crack on camera?
Joints appear at regular intervals as full rings around the pipe. Cracks are irregular lines that may run along the pipe, around it, or in a spiral, and they do not repeat at a set spacing.
Is a transition from clay to PVC a problem?
Not by itself. It usually marks a past repair or a replaced section. Check the coupling for an offset or gap and ask whether the remaining clay is in similar condition to the part that was replaced.
Can I watch the inspection live?
Usually yes. Most push camera systems have a monitor, and watching live lets you ask the operator to pause, rotate the view or re-examine a spot.
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