· 6 min read · Taylor Plumbing
New build plumbing isn't one job, it's several, spaced out across the build programme and tied to inspections at each stage. Get the timing wrong and you can hold up the builder, the slab pour, or the code compliance certificate at the end. Get it right and it's one of the smoothest parts of the whole build.
With so much new residential building happening in Selwyn and Waimakariri as well as the rebuild areas of Christchurch itself, we work alongside builders on this sequence regularly. Here's how it typically runs.
Stage 1: Drainage before the slab
Wastewater and stormwater pipework goes in before the concrete slab is poured, laid out to match the approved plans so every fixture location has a drain waiting for it underneath. This stage needs a council drainage inspection before the slab can be poured over it.
Getting this stage right matters more than any other, since fixing a drainage mistake after the slab is down is a far bigger job than getting it right first time.
Stage 2: Pre-slab water and gas rough-in
Water supply pipe and, where the build includes gas, the gas pipe rough-in for under-slab runs happen at the same time as drainage, following the same principle of matching fixture positions to the plans before they're buried in concrete.
Stage 3: Framing rough-in
Once the frame is up, pipework for taps, showers, toilets and the hot water cylinder gets run through the walls and ceiling space before the gib goes on. This is when pipe positions for vanities, showers and the kitchen are locked in, so it pays to have any late layout changes finalised before this stage starts.
Stage 4: Pressure testing
Before gib covers the pipework, the system gets pressure-tested to confirm every joint is sound. This is a key checkpoint, since finding a leak after the walls are lined means cutting back into finished gib.
Stage 5: Fit-off
Once linings, tiling and cabinetry are in, we come back to install and connect the visible fixtures: taps, toilets, the hot water cylinder or continuous flow unit, dishwasher and washing machine connections, and gas appliances if the build includes them.
Council sign-offs along the way
- Drainage inspection before the slab is poured
- Pre-line inspection covering rough-in pipework before gib goes up
- Final plumbing and drainage inspection before code compliance is issued
- Gas certification for any gas fitting work, separate from the general plumbing sign-off
Working with builders in Selwyn and Waimakariri
New build programmes in growth areas like Rolleston, Lincoln, Rangiora and Kaiapoi move fast, and each council has its own inspection booking system and lead times. We coordinate directly with the builder's site programme so drainage, rough-in and fit-off line up with the concrete, framing and lining schedule rather than causing a hold-up.
If you're an owner-builder or managing your own build rather than going through a group builder, we're happy to talk through the sequence with you directly so you know what's needed before each inspection.
Frequently asked questions
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New build plumbing for Christchurch, Rolleston and Lincoln. From slab prep to final sign-off with the paperwork sorted.
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