Responsibility
Who Is Responsible for a Blocked Drain?
Your pipe, Watercare's main, or Auckland Council's stormwater? The boundary decides who pays — and it takes about thirty seconds to work out.
Bathrooms
A blocked shower drain is nearly always a plug of hair bound together with soap scum, sitting within a hand's reach of the grate. Lift the grate, pull the hair out with a gloved hand or a hair-catch tool, then flush with hot tap water and a squirt of dish soap. If it is still slow, plunge it with the bath overflow or any second outlet sealed. The same steps work for a bath. Our guide to unblocking a drain yourself covers the wider toolkit. If other fixtures are slow too, the blockage is further down and the shower is just where it shows.
Shower drains block because hair does not break down in water and soap does not stay dissolved. Hair is made of keratin, a tough protein, and strands snag on the grate, the trap and any rough joint. Soap reacts with minerals in the water to leave soap scum, a waxy residue that coats the strands and glues them into a mat. Conditioner, body oils and shaving foam add to it.
The mat builds slowly. For weeks the shower just drains a little lazily, then one day water is pooling around your feet. That gradual slide is the giveaway that the problem is local: a sudden blockage with nothing beforehand is more likely to be something further down the line.
Where the hair collects depends on what kind of outlet you have. Most Auckland bathrooms have one of these four.
| Outlet | What it looks like | Where the hair collects |
|---|---|---|
| Tiled-shower floor waste | A round or square grate set into the tiles, usually in a corner or the middle of the floor | Under the grate and in the trap below it. Many have an easy-clean trap with an insert that lifts straight out for cleaning. |
| Linear or channel drain | A long, narrow grate along one wall or across the entry of a level-entry shower | Along the floor of the channel, and in a ball at the outlet at one end or in the middle |
| Shower tray waste | A domed or flat cover in the middle of a moulded acrylic or stone tray | Wrapped around the cover's stem and in the trap. Some covers pull off; others are held by a single screw. |
| Bath waste and overflow | A plug hole in the base and an overflow slot near the top of the bath | Around the plug mechanism and in the trap. The overflow joins the waste pipe below the plug. |
Work from the top down, and stop as soon as the water runs freely. Bail out any standing water first, then lift the grate and pull out the hair you can see. Use a hair-catch tool or plastic barbed strip for what sits further in, flush with hot water and dish soap, and only then reach for the plunger. Most shower blockages clear at the first or second step.
Leave the waste fitting itself alone. The grate, a lift-out insert and a screw-held cover are all made to come off. The body of the waste and the trap are not: in a tiled shower the waterproofing membrane is sealed onto the waste's flange, and the Plumbers, Gasfitters, and Drainlayers Board lists fixing or unfixing a trap or waste pipe among the plumbing work homeowners cannot do themselves.
Nothing you would want sitting in your shower. Hair is built to survive water, soap and heat, so pantry remedies barely touch it. Strong caustic drain products can break hair down, which is why they sell, but they do it with a corrosive chemical that sits in a slow drain at the level of your feet. For a hair plug a short reach from the grate, pulling it out is faster, safer and more certain.
The chemistry is real: concentrated sodium hydroxide (caustic soda) breaks down the protein in hair. The problem is what comes with it. It burns skin and eyes, it generates heat in the pipe, and in a shower that is only slow rather than stopped, the product lingers right where you stand. If you do use one, follow the label exactly and never combine it with anything else. We explain what drain cleaners actually do, and when they are worth it, in a separate guide.
Only a little. Baking soda (sodium bicarbonate) and vinegar react to make sodium acetate, water and carbon dioxide. The fizz is mostly the two cancelling each other out, and what is left is a weak salt solution. It is harmless and can freshen a drain that smells or is only slightly slow, but it will not shift a mat of hair.
That is why plumbers are lukewarm about it: not because it does damage, but because people try it for a real blockage, wait, try it again, and lose a day. If you want to use it as a monthly freshener, go ahead, and follow it with hot tap water. For a shower that is actually holding water, start with the grate and the hair-catch tool.
Don't pour chemicals into a shower that is holding water, don't mix products, and don't plunge after a chemical has gone in. A slow drain means the product sits there undiluted where you will splash it, and a plunger can throw it back at you. Also avoid boiling water on plastic pipe, and don't prise out the waste fitting itself.
Rinse with plenty of running water straight away and keep rinsing. For advice on what to do next, call the National Poisons Centre on 0800 764 766, any time. If someone has swallowed a drain product or is badly burned, call 111.
Watch the other fixtures. A shower that is slow on its own is a shower problem. If the basin or bath in the same room is also slow, the shared branch pipe is the likely spot. If the toilet rises when the shower runs, the shower fills when the toilet is flushed, or the outside gully trap is full, the blockage is in the main line outside.
A few specific patterns are worth knowing:
Our guide to the signs of a blocked drain walks through how to read these together. If wastewater is also surfacing in the street or your neighbours have the same problem, the public main may be involved: Watercare asks you to call its faults line on (09) 442 2222, option 1.
In an older house the shower is often new and the drainage under it is not. A renovated bathroom in a villa or bungalow can sit on a long run of older pipe to the gully, and the main line outside may be jointed earthenware or concrete laid before 1960. Slow drainage there can come from build-up along that run, not just hair at the grate.
Two things tend to separate the two. If clearing the grate and trap fixes the shower for months, it was hair. If the shower is slow again within days, or it is slow even when the grate and trap are clean, the restriction is likely further along: a sagging section, a rough joint that catches everything, or roots in an old outside lateral. Those are not DIY jobs, and a camera is the only way to know which one it is.
Catch the hair before it goes down. A hair catcher that sits over or inside the grate costs little and does most of the work; emptying it after each shower takes seconds. Add a quick clean of the grate once a week and a hot-water flush with dish soap once a month, and most showers never block badly again.
The bathroom basin blocks the same way, from hair, soap and toothpaste, and the fix is similar. Our guide to unblocking a bathroom basin or sink covers it, and the list of what not to put down the drain covers the rest of the house.
Call when two rounds of DIY have not worked, when water will not move at all, when other fixtures are affected, or when wastewater is coming up through the shower from elsewhere. Also call if the job needs the waste or trap taken apart. Clearing a blocked drain is something you are allowed to do yourself; unfixing or refitting a trap or waste is restricted work.
When you phone, tell us which outlet you have, what you have already tried, and whether anything else in the house is slow. That is usually enough to say whether it is a shower clear or a drain unblocking job further down the line, and roughly what drives the cost before anyone arrives. The drainlayer who attends carries the tools a home kit does not: a powered machine for the line, and a camera if the shower keeps blocking. Restricted sanitary plumbing and drainage work is done by licensed tradespeople, and you can check anyone's licence on the PGDB public register.
If you rent, a slow shower is usually something you can try to clear yourself first, but a shower that keeps backing up is a landlord issue. Our page on blocked drains in rental properties covers who pays.
Dish soap followed by a few litres of the hottest water from your tap is the most useful thing to pour, because the detergent loosens the soap scum holding hair together. Baking soda and vinegar is harmless but weak. Nothing poured will remove a mat of hair, though, so lift the grate and pull the hair out first, then flush.
It is better not to. Shower wastes and the pipes under them are mostly plastic, and boiling water can damage some plastic fittings and seals. It also does little to hair. Use hot water straight from the tap with a squirt of dish soap instead, after you have cleared what you can reach under the grate.
The hair is often just out of sight, wound into the trap below the grate or around the stem of a tray cover. A hair-catch tool or plastic barbed strip will usually bring it up. If the trap is genuinely clean and the shower is still slow, or other fixtures are slow too, the restriction is further down the line.
Usually not for the first attempt. Lifting the grate, removing hair, flushing and plunging fix most shower blockages, and clearing a blocked drain is work homeowners are allowed to do. Call someone if it is still slow after two tries, if other fixtures are affected, or if the trap or waste would need taking apart, which is restricted work.
The usual cause is hair and soap residue in the trap breaking down and growing a slimy film, which smells musty or sour. Cleaning the grate and trap and flushing with hot soapy water normally fixes it. A shower that is rarely used can also lose the water in its trap; run it for a minute. A sewage smell outside as well suggests a drain problem.
Tell us what it is doing and we will tell you what it probably is, what it takes to fix, and what that should cost.