Concreters and drainlayers frequently work on the same project — think driveways, paths, and outdoor areas where stormwater drainage is part of the job. However, in New Zealand there is a clear legal distinction between concreting work and drainage work, and crossing that line without the right licence can land both the tradesperson and the homeowner in trouble.
What Does a Concreter Actually Do?
A concreter specialises in forming, pouring, finishing, and curing concrete. This includes driveways, paths, slabs, retaining walls, and decorative concrete work. Concreters may also install channel drains (like ACO drains) that sit within or alongside concrete surfaces — but only up to a point. The key question is: where does that drainage connect to?
What Is Restricted Drainlaying Work in NZ?
Under the Plumbers, Gasfitters, and Drainlayers Act 2006, drainlaying is restricted work in New Zealand. This means that connecting, laying, altering, or repairing any drain that connects to the public sewer or stormwater network — or to an on-site wastewater system — must be carried out by a licensed drainlayer registered with the Plumbers Gasfitters & Drainlayers Board (PGDB).
This includes:
- Connecting a new drain to the council stormwater system
- Laying underground stormwater or wastewater pipes
- Altering existing drainage connections
- Installing soakage systems that are part of a regulated drainage network
A concreter who is not a licensed drainlayer cannot legally perform these tasks, regardless of how experienced they are with concrete work.
What Can a Concreter Legally Do?
There is some overlap between the two trades, and a concreter can legally carry out certain drainage-related tasks without a drainlaying licence:
- Installing surface channel drains (e.g. ACO-style strip drains) within a concrete driveway or path, provided the outlet does not connect to a regulated drain
- Forming concrete around existing drainage infrastructure
- Shaping and grading concrete surfaces to direct water flow (falls and crossfalls)
- Installing agricultural drainage in some rural contexts (though this can vary — always check with your local council)
The grey area is often where a surface drain discharges. If it flows to a garden bed or a legal point of discharge on your own property, a concreter may be able to handle it. If it connects to the council stormwater network, a licensed drainlayer must be involved.
The NZ Building Code and Consent Requirements
Drainage work is also subject to the NZ Building Code, particularly Clause E1 (Surface Water) and Clause G13 (Foul Water). Depending on the scope of work, a building consent may be required before drainage work begins. Some minor drainage work may fall under Schedule 1 exemptions, but this varies by council and by the nature of the work.
Always check with your local council before starting any drainage project to confirm whether consent is needed and what licensed trades must be involved.
Can One Person Hold Both Licences?
Yes — it is perfectly legal for a tradesperson to hold both a concreting background and a drainlaying licence from the PGDB. Some experienced contractors do hold dual qualifications, which means they can legally carry out both types of work on the same job. If your concreter claims they can do the drainage work, ask to see their PGDB registration. You can verify a drainlayer's licence directly on the PGDB website.
Practical Tips for Homeowners
- Ask upfront: Before hiring, ask your concreter exactly what drainage work they plan to do and whether they hold a drainlaying licence.
- Get it in writing: Make sure the scope of work in your contract clearly states who is responsible for drainage connections.
- Check with your council: Confirm consent requirements and whether the drainage work needs to be inspected.
- Don't assume: Just because a concreter has done drainage work before doesn't mean it was done legally.
- Use licensed trades: Unlicensed drainage work can void your home insurance, create liability issues, and cause problems when you sell your property.
For guidance on what work requires consent, MBIE Building Performance is an excellent starting point.
When to Call a Professional
If your project involves any connection to the council stormwater or wastewater network, you must engage a licensed drainlayer. This is non-negotiable under NZ law. For larger projects involving both concrete and drainage, look for a contractor who holds both qualifications, or engage a concreter and a licensed drainlayer to work together.
You can find qualified local concreters and licensed drainlayers in your area on tradedirectory.co.nz. Always ask for proof of relevant licences and check references before work begins.
Safety note: Improper drainage can cause flooding, structural damage, and contamination of waterways. Always use licensed professionals for regulated drainage work.
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