A leaking outdoor hose tap (also called a garden tap or bib tap) is one of the most common and straightforward plumbing jobs a NZ homeowner can tackle themselves. In most cases, the culprit is a worn rubber washer inside the tap body — a part that costs just a few dollars and takes less than half an hour to replace.
Is This Legal for a Homeowner to Do?
In New Zealand, certain plumbing work is restricted work that must be carried out by a licensed plumber registered with the Plumbers Gasfitters & Drainlayers Board (PGDB). However, replacing an internal tap washer on an existing tap is generally considered routine maintenance that a homeowner may legally do themselves — you are not altering the pipework or installing new fittings.
If you need to replace the entire tap, extend pipework, or move the tap location, that becomes restricted work and you must hire a licensed plumber. When in doubt, check with the PGDB or your local council.
Tools and Materials You'll Need
- Adjustable spanner or shifting spanner
- Flat-head screwdriver
- Replacement tap washer (most outdoor bib taps use a 12 mm or 15 mm fibre or rubber washer — check your existing washer size)
- Replacement O-ring (good idea to replace this at the same time)
- Plumber's grease (silicone-based)
- Old towel or bucket
Replacement washers and O-rings are widely available at Bunnings, Mitre 10, and PlaceMakers. As a rough guide, a pack of assorted tap washers costs a few dollars.
Step-by-Step: Replacing the Washer
1. Turn Off the Water Supply
Locate your toby (water meter) valve at the boundary of your property or the internal stopcock closest to the tap. Turn it off fully. Open the hose tap to release any remaining pressure and drain the line. Place a towel or bucket underneath to catch drips.
2. Remove the Tap Handle
Most outdoor bib taps have a simple cross or lever handle. Look for a small screw on top of the handle (sometimes hidden under a decorative cap) and undo it with a screwdriver. Lift the handle off.
3. Unscrew the Headgear
Using your adjustable spanner, turn the headgear nut (the large hexagonal nut just below the handle) anti-clockwise to unscrew it. Pull the headgear assembly straight out of the tap body. You may need to wiggle it gently.
4. Replace the Washer
At the bottom of the headgear spindle you'll see the old washer, usually held in place by a small brass nut or a retaining clip. Undo the nut (or prise off the clip), remove the old washer, and fit the new one. Make sure it sits flat and is the correct size — a poorly fitting washer won't seal properly.
While you have the headgear out, inspect the O-ring around the spindle and replace it if it looks cracked or flattened. Apply a small amount of silicone plumber's grease to the new O-ring before reassembly.
5. Reassemble and Test
Screw the headgear back into the tap body hand-tight first, then snug it up with the spanner — do not overtighten, as this can crack the tap body. Refit the handle and its retaining screw. Slowly turn the water supply back on and check for leaks around the headgear and at the tap outlet. Open and close the tap a couple of times to confirm it seals correctly.
Common Problems and What They Mean
| Symptom | Likely Cause | Fix |
|---|---|---|
| Dripping from tap outlet when closed | Worn washer | Replace washer |
| Leaking around the handle/spindle | Worn O-ring or packing | Replace O-ring or repack |
| Tap still drips after new washer | Damaged tap seat | Re-seat or replace tap |
| Leak from the wall fitting | Loose or corroded connection | Call a licensed plumber |
If the tap seat (the brass surface the washer presses against inside the tap body) is scored or pitted, a new washer alone won't fix the drip. A tap seat re-seating tool can grind it smooth, but if you're not confident, this is a good point to call in a professional.
Why Fix It Promptly?
Even a slow drip wastes a surprising amount of water over time — and in NZ, water charges and environmental responsibility both make it worth fixing quickly. Under the Healthy Homes Standards, rental properties must have functional plumbing, so landlords should address leaks without delay.
When to Call a Professional
Call a licensed plumber (find one on tradedirectory.co.nz) if:
- The leak is coming from the pipework inside the wall, not the tap itself
- You need to replace the entire tap or relocate it
- The tap body is cracked or heavily corroded
- You're not comfortable turning off the toby or working with the water supply
- The tap seat is damaged and you don't have the right tools to re-seat it
Always verify your plumber is licensed via the PGDB register.
Safety note: Never work on any plumbing while the water supply is still on. If you can't locate or operate your toby valve, contact your local council or a licensed plumber before proceeding.
Master Plumbers
