Once a year, every year
In March 2026 a Wanneroo homeowner got in touch about a sewer that had blocked roughly once a year for the last three years. They knew the pipe had been relined by another company about 15 years earlier, but not which part. They suspected tree roots, and the plumber they’d been using had told them the line would need to be dug out.
Digging up a sewer line is a big, disruptive job. Before anyone does that, it’s worth knowing exactly what is down there and where.
Down the line from the shaft
We put a camera in at the sewer inspection shaft, the capped riser in the backyard that gives straight access to the main line, and ran it downstream. The tail end of the old reline had folded over inside the pipe, and that fold was what kept catching waste and blocking the line. At the time of that inspection, there were no tree roots to be seen.
A reline is a new pipe formed inside the old one: a liner soaked in resin is pushed into place and cures hard. Done well, it seals cracks and joints from the inside. The weak point is where it ends. If the edge of a liner lifts or folds, it leaves a lip across the pipe that waste keeps snagging on.
Cut it back, then look again
Our recommendation was neither to dig nor to reline straight away. We recommended cutting back the folded section with specialist equipment first, then reassessing for roots once we could see the original pipework properly.
The reason is measurement. The Australian standard for relining is to cover a crack or damaged section of pipe by 450 mm each way. You can’t size a new liner properly while an old one is folded over the very spot you need to look at.
What was behind the fold
On the return visit our tech milled the tail end of the old liner smooth. With the fold gone, the camera could see what had caused it: a large root at that point, which is what had made that section of liner fail.
So the homeowner had been half right all along. There were roots, but they were behind the reline, not in open pipe. We recommended relining over that section and sent a quote for the work.
Had your drains relined before?
- A reline has two ends. If a relined sewer starts blocking again, ask for the camera to check exactly where the old liner finishes.
- Keep the paperwork. Knowing where an earlier reline was done saves time and guesswork years later.
- Repeat blockages don’t automatically mean digging. Footage of the pipe shows whether a section really needs to come out or can be repaired from inside.
If roots are a regular problem at your place, our tree root blockage page covers how we deal with them. For a drain in Wanneroo that keeps blocking, call 0499 281 430.
More on blocked drains in Wanneroo, or see more recent jobs.
