· 6 min read · Taylor Plumbing
A kitchen renovation lives or dies on decisions made before the cabinetry arrives. Once the benchtop is templated and the joinery is screwed to the wall, moving a waste outlet or adding an extra tap point becomes expensive and messy.
We get called into a lot of Christchurch kitchens after the fact, when a dishwasher won't fit under the new bench or a sink is sitting over a waste that's twenty years old. Getting the plumbing right early saves both money and a second visit from the kitchen installer.
Plan the sink and waste position first
The sink waste needs a fall to the main drain, and that fall is fixed by where the pipe already runs under the floor. If you're moving the sink to an island or the opposite wall, we need to check whether the existing waste run can reach it with enough gradient, or whether a macerator or repositioned drain is needed.
In older Christchurch villas with suspended timber floors this is usually straightforward. In newer slab-on-grade homes in places like Rolleston or Pegasus, moving a waste means cutting the slab, which is worth knowing before you commit to a layout.
Choosing a mixer
Pull-out mixers are popular for a reason, they make washing large pots easier, but they need adequate water pressure to work well. If your home runs on a low-pressure gravity-fed hot water cylinder, some higher-end mixers won't perform properly. We can check your system's pressure before you buy.
Filtered water taps and boiling water taps both need an extra under-bench unit and often their own power point, so tell your electrician and plumber at the same time, not one after the other.
Appliance connections
- Dishwashers need a hot or cold water connection (check the manual), a waste connection with a high loop or air gap, and an isolating valve within reach
- Fridges with water/ice need a dedicated small-bore water line run before the cabinetry goes in
- Gas hobs need a certified gasfitter to run and pressure-test the line, and a compliance certificate at the end
- Instant boiling/chilled water units need their own isolating valve and usually a dedicated circuit
Isolating valves matter more than people think
Every tap, dishwasher and fridge connection should have its own isolating valve. Without one, a future leak or repair means shutting off the whole house at the toby. It's a small cost during a renovation and a real hassle to retrofit once the cabinetry is in.
Order of trades matters
Rough-in plumbing (pipework in the walls and floor before linings go on) has to happen before the gib goes up. Final fit-off of the sink, mixer and appliances happens after the benchtop is installed and templated. If a kitchen company templates before rough-in plumbing is confirmed, waste and tap positions can end up in the wrong spot on the new benchtop.
Common mistakes we see
- Benchtop cut for a sink before the plumber confirms the waste position
- No isolating valve fitted for the dishwasher
- Boiling water tap installed without checking bench thickness for the tap body
- Gas hob connected without a compliance certificate
Frequently asked questions
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Kitchen plumbing across Christchurch. Sinks, mixers, dishwashers, ice-maker fridges and gas hob connections.
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