A tap that leaks around its base — pooling water on the bench or vanity rather than dripping from the spout — is almost always caused by a worn O-ring or deteriorated packing material around the tap body. This is one of the more approachable plumbing DIY jobs for a NZ homeowner, and with the right parts and a bit of patience, you can usually sort it in under an hour.
Understanding Why a Tap Base Leaks
When water seeps out from where the tap body meets the sink or basin, the culprit is typically:
- Worn O-rings — rubber rings that seal the rotating or moving parts of the tap body
- Deteriorated packing — older taps use graphite or fibre packing rope around the spindle
- Loose tap body — occasionally the tap itself has simply worked loose from the bench
Knowing which type of tap you have (ball, ceramic disc, or older compression/jumper valve) helps you buy the right parts before you start.
Tools and Materials You'll Need
- Adjustable spanner or basin wrench
- Flathead and Phillips screwdrivers
- Needle-nose pliers
- Replacement O-rings (a mixed pack covers most sizes)
- Plumber's grease (silicone-based)
- Packing rope or replacement cartridge (if applicable)
- Cloth or small bucket
- Torch
Replacement O-rings, cartridges and packing rope are widely available at Bunnings and Mitre 10. Take the old O-ring with you to match the size, or photograph the tap brand/model to ask staff for help.
Step-by-Step: Fixing a Leaking Tap Base
1. Turn Off the Water Supply
This is the most important step. Locate the isolating valve under the sink (turn clockwise to close) or, if there isn't one, turn off the water at the toby (main stopcock) — usually near the boundary or under a small lid in the front garden. Open the tap to release any remaining pressure and drain the line.
2. Disassemble the Tap
- Remove the tap handle — there's usually a decorative cap hiding a screw on top. Unscrew it and lift the handle off.
- Use your spanner to unscrew the packing nut or gland nut — the large nut at the base of the tap body. Turn anticlockwise.
- Carefully lift out the spindle or cartridge assembly.
3. Inspect and Replace the O-ring or Packing
- Look for O-rings seated in grooves around the spindle or cartridge body. If they look flattened, cracked, or shiny, they need replacing.
- Roll the new O-ring into the groove — do not stretch it. Apply a thin smear of silicone plumber's grease to help it seat properly and extend its life.
- If your tap uses packing rope, remove the old material with needle-nose pliers and wind new packing rope clockwise into the gland before reassembling.
4. Check the Tap Body Is Secure
While you have things apart, check the tap body locknut underneath the bench. If it's loose, tighten it with a basin wrench — this alone sometimes stops the leak.
5. Reassemble and Test
- Reassemble in reverse order. Hand-tighten the packing nut first, then snug it up with the spanner — do not overtighten, as this can crack older fittings.
- Slowly turn the water supply back on and watch the base carefully for any drips.
- If it still weeps slightly, try tightening the packing nut by a quarter turn at a time.
NZ Regulatory Context: What Homeowners Can and Can't Do
In New Zealand, routine maintenance such as replacing washers, O-rings, tap cartridges and packing on existing fittings is generally considered work a homeowner can legally carry out on their own home. However, any work that involves altering, extending or connecting to the water supply pipework is restricted work under the Plumbers, Gasfitters and Drainlayers Act 2006, and must be carried out by a licensed tradesperson registered with the Plumbers Gasfitters & Drainlayers Board (PGDB).
If you're a landlord, also be aware of your obligations under the Healthy Homes Standards — a dripping or leaking tap can contribute to moisture issues that affect compliance.
For general guidance on what work requires consent or a licensed professional, MBIE Building Performance is a reliable starting point.
When to Call a Professional
Some situations are best left to a licensed plumber:
- The leak is coming from the supply pipes rather than the tap body itself
- You find corrosion, cracks or damage to the tap body or fittings
- The tap is very old and parts are no longer available — replacement may be smarter
- You're not confident working around water supply systems
- The leak persists after replacing O-rings and packing
- You need to move or extend any pipework
A qualified local plumber can diagnose the issue quickly and ensure the repair meets the NZ Building Code. You can find licensed plumbers in your area on tradedirectory.co.nz.
Safety note: Always confirm the water is fully off before disassembling any tap. Keep a towel handy and have a bucket under the work area. If you're unsure at any point, stop and call a professional — water damage to cabinetry and subfloors can be costly.
Master Plumbers
