Blocked drain Bronte: under-house fix

The basin in this Bronte home had stopped draining. Water sat in the bowl and would not go down. Like a lot of houses in Bronte, this one sits on a subfloor, and all of its waste pipes run underneath the house rather than through a concrete slab.

That made the fix a lot simpler than it could have been. There was no need to dig or lift a single tile, because the way in to this blocked drain was already built into the bathroom wall.

Getting to the blocked drain through an access panel

Whoever renovated this bathroom put a hinged access panel into the tiled wall beside the vanity. Open it up and you are looking straight into the subfloor, at the basin, shower and toilet waste lines where they drop down and join before heading out to the sewer.

Greg climbed through the panel into the subfloor, followed the basin line and found the blockage. The photo above is taken from the bathroom side, looking in at him under the house.

Clearing the blockage with a jetter

Greg cleared the line with the high-pressure water jetter. A jetter does more than punch a hole through a blockage. It scours the inside of the pipe wall as it goes, so the build-up that caused the problem is washed out rather than just pushed further along.

Before packing up, Greg ran water through every fixture in the bathroom, not just the basin, to check the whole system was flowing freely. When a branch line blocks, it is worth confirming the lines it joins are clear too, so the customer is not calling back a week later about the shower.

Why subfloor homes in Bronte are easier to fix

Bronte's streets fall steeply toward the beach, and many houses sit on sloping blocks with a subfloor underneath. In those homes the drainage runs through the space under the floor, where a plumber can usually reach it. On a concrete slab, the same pipes are cast into or buried under the floor, and getting to a problem can mean cutting into it.

Not every subfloor is easy to get into. Some only have a small opening at the side of the house, or barely enough height to crawl. An access panel inside the bathroom, like the one in this Bronte home, puts the plumber right next to the pipes that serve the room.

If you have an access panel like this, keep it clear and do not tile over it during a renovation. It makes any future drain work quicker and cheaper.

What usually blocks a bathroom basin drain

In our experience, a blocked basin is most often a slow build-up of hair, soap scum and toothpaste that catches in the pipe and narrows it over time. Sydney Water's Save Our Sinks guidance is a good rule of thumb: only water, detergent and soap should go down the sink. For more ways to keep drains clear, read how to prevent blocked drains in the Eastern Suburbs.

Signs your basin drain is blocking

• The basin drains slower every week. Build-up narrows the pipe gradually, so a basin that used to empty in seconds starts to hold water.
• Gurgling from the basin or a nearby fixture when water goes down, which means air is being pushed past a partial blockage.
• A bad smell coming up from the plughole, from waste sitting in the pipe instead of flowing away.
• In a subfloor home, a musty or sewage smell under the house, or damp patches in the subfloor. That can mean a pipe joint is leaking, not just blocked, and is worth getting checked quickly.

If a blocked drain keeps coming back after it has been cleared, the cause may be further down the line. We explain why in Blocked drains in Sydney's Eastern Suburbs: why they keep coming back.

Contact Norton Plumbing

Norton Plumbing has cleared blocked drains across the Eastern Suburbs since 2019, from Bronte and Clovelly through to Bondi, Coogee and Randwick. Adam Norton is the primary plumber on the tools and holds NSW plumbing licence 397768C. Phone 0477 858 951. Based at 10/11a-15 Berwick Street, Coogee NSW 2034. See our blocked drains service page or our Bronte plumber page.