A sink out the back
In July 2026 we were called to a shop in a Kallaroo shopping strip with a blocked back-of-house sink. It’s the working sink out the back, away from the shop floor, and when it stops draining the back room stops with it. The booking noted the store didn’t open until after 10, so the visit was arranged around that.
Most of our Kallaroo work is in homes, mainly roots in old sewer lines. A commercial sink line is a different animal. More water goes down it, more often, and the pipework behind older shops has usually been there a long time.
Starting at the gully
The drain gully for the sink sits outside, tucked in behind the building among a tangle of service hoses (it’s the cover photo). That was our way in. We ran the hydro jetter through the gully, a high-pressure water hose with a nozzle that drives itself along the pipe and blasts the walls as it goes, then followed it with a CCTV camera to see what had actually been holding the water back.
What the camera found
The camera showed heavy grease build-up on a section of pipe upstream of a jump-up. A jump-up is a spot where the drain rises to meet a fixture higher than the line it runs into. Flow changes direction there, and that’s where fat tends to collect.
That section was galvanised steel. Old galvanised pipe rusts on the inside and the surface goes rough. Grease grabs onto rough metal far better than it grabs onto smooth PVC, and it builds up in hard layers that tradies call scaling. Each layer narrows the pipe a little more.
Flowing is not the same as fixed
After jetting, the sink drained properly again. That needed some context, though. With that much grease scaled onto that much tired galvanised pipe, jetting improves things but doesn’t remove the cause. The rough pipe is still there, and it will start collecting fat again.
So the recommendation was to treat the pipe, not just the blockage. We put together a separate quote for milling the affected galvanised section. Milling uses a cutting head that spins inside the pipe and grinds hard scale and corrosion back toward the pipe wall, which jetting alone can’t do. Where the pipe is too far gone, that section gets replaced instead. Either way, the goal is a line that stops blocking, not one that needs jetting again and again.
For anyone running a shop or a kitchen
- Know what your pipes are made of. If the building is older, there’s a fair chance some of the line behind your sinks is galvanised steel, and it holds grease far worse than PVC.
- Warm fat doesn’t stay liquid. It cools and sets once it’s further down the line, usually at a bend or a rise like a jump-up.
- A blockage that keeps coming back is a pipe problem. If jetting clears it and it returns, a camera inspection will show whether the pipe itself is the issue.
We look after commercial blocked drains, and hydro jetting is usually where we start. If a sink out the back of your Kallaroo business keeps backing up, call 0499 281 430.
More on blocked drains in Kallaroo, or see more recent jobs.
