Clearing a drain and fixing one are different jobs. Here’s what the camera shows once the water is running again, and why it decides whether you’re back.
Post written in Collaboration with All Needs Plumbing
The drain is running again. The machine goes back on the ute, the invoice gets paid, and everyone moves on.
Three months later the same drain blocks in the same spot.
Our crew runs drain cameras across southern Sydney most days, and the thing that comes up again and again is this: clearing a drain and fixing one are two different jobs, and most people only buy the first because nobody explained the difference.
Bec has already written the definitive piece on what causes blockages, including the tree root problem and the ten usual suspects. This is the part that comes after. What the camera actually shows once the water is moving, and why that footage is the bit that decides whether you are back in three months.
Here’s what we’ll go through:
- Why a cleared drain tells you almost nothing about the state of the pipe
- The fault nobody can hear, see or smell, and only a camera finds
- Why roots that look like they’ve gone usually haven’t
- What to ask for when someone runs a camera down your drain
Clearing A Drain And Fixing One Are Not The Same Job
A jet blaster or an electric eel will shift almost anything soft. Paper, fat, wipes, hair, a root mat that has not had time to go woody. The water runs, the gurgling stops, and the symptom is gone.
What the clear does not tell you is why the blockage formed at that exact point. Drains do not block at random. They block where something is holding material up, and that something is almost always still there once the paper has washed through.
That is the entire argument for putting a camera down afterwards rather than instead. We run a camera inspection on blocked drain jobs for that reason: the clear fixes today, and the footage tells you what next winter looks like.
On one job the reported problem was a blocked toilet. The camera found exactly what you would expect, a paper blockage sitting at the bottom of the junction. Cleared in twenty minutes. Then we kept the camera going downstream and found the top half of the shaft squashed flat, with roots coming in about half a metre below ground. None of that was audible, visible or smellable from the house. The blockage was the symptom. The squashed shaft was the job.
The Fault Nobody Can Hear, See Or Smell
The one that surprises homeowners most is back-fall.
A drain works on gravity. It needs a consistent fall along its whole length, and the National Construction Code and AS/NZS 3500.2 set minimum grades for exactly that reason. Where a section has dropped, or was laid badly in the first place, you get a stretch of pipe running the wrong way.
Water still gets through. It just slows down, and anything solid stops in the dip and stays there.
We had a job that came in as a gurgling kitchen sink. Camera down the sewer line first: nothing upstream of the manhole, which rules out the obvious. Cut a section out under the subfloor, camera down that, and there it was. The line was back-falling where it ran out under the decking.
You cannot hear back-fall. You cannot smell it. It does not show up as a blockage until something stops in it. And a jet blaster will clear it perfectly, then it will refill, because the pipe is still pointing the wrong way.
Roots That Look Like They’ve Gone
Roots are the one everybody knows about, and still the one most often misread.
On a job in Sydney’s south we cut out and replaced a section of sewer, then came back a couple of days later to camera the rest of the line. Roughly half the root intrusion we had seen on the Saturday had cleared out of the drain by itself, washed downstream.
It would have been very easy to call that fixed. The shaft was still heavily infested. The roots had not gone anywhere, they had just moved.
This is why a camera run *before* the quote and a camera run *after* the work are different pieces of information, and why a drain that has been jetted can look dramatically better on footage without being in any better condition structurally. The root mat is gone. The crack the roots came through is exactly where it was.
What To Ask For When Someone Runs A Camera
If you are paying for a camera inspection, you should get more than a plumber’s word for it.
Ask for the footage, not a summary of it. Most modern units record. Ours is a RIDGID SeeSnake, and there is no reason you cannot be shown the screen while it is happening.
Ask where the fault is, in metres from a known point, not “out the back somewhere”. A camera with a locator tells you the position and the depth, which is the difference between a targeted dig and a guess.
Ask what the pipe is made of. Anything laid before about 1980 is likely earthenware in short sections with mortar joints, and those joints are where roots come in. PVC behaves differently and fails differently.
Ask whether the blockage was a cause or a symptom. It is a fair question and a good plumber will have an answer either way.
The Short Version
A cleared drain and a healthy drain look identical from the kitchen sink. The only thing that tells them apart is footage of the inside of the pipe.
If a drain has blocked twice in the same place, the second clear is the one worth questioning. Something down there is holding material up, and until somebody looks, you are buying the same twenty minutes over and over.
