Replacing broken drain pipes in New Zealand is not as straightforward as it might seem — the law is quite specific about who can legally carry out this work. While a drain cleaner can unblock and maintain drains, actually replacing broken or damaged pipework is classified as restricted work under New Zealand law, meaning it must be carried out by a licensed professional.
What Is Restricted Work in New Zealand?
Under the Plumbers, Gasfitters and Drainlayers Act 2006, drainlaying — which includes the installation, replacement, alteration, or repair of drain pipes — is restricted work. This means only a person who holds the appropriate licence issued by the Plumbers, Gasfitters and Drainlayers Board (PGDB) can legally carry out this work.
The key licence types relevant here are:
- Licensed Drainlayer – authorised to carry out drainlaying work on sanitary drains and stormwater drains.
- Licensed Plumber – may also carry out certain drainlaying work depending on their scope of licence.
- Certifying Drainlayer – can certify that restricted drainlaying work complies with the relevant standards.
A general drain cleaner or drain unblocking technician who does not hold one of these licences cannot legally replace broken drain pipes, even if they are experienced at clearing blockages.
What Can a Drain Cleaner Legally Do?
A drain cleaner — someone who specialises in unblocking and maintaining drains — can legally carry out maintenance tasks that do not involve altering or replacing pipework. This typically includes:
- High-pressure water jetting to clear blockages
- CCTV drain inspections to locate damage or blockages
- Removing tree roots or debris from pipes
- Chemical or mechanical drain clearing
However, once a CCTV inspection reveals a broken, cracked, collapsed, or misaligned pipe, the repair or replacement of that pipe becomes restricted drainlaying work. At that point, a licensed drainlayer or certifying drainlayer must take over.
Does Replacing a Drain Pipe Require a Building Consent?
This depends on the nature and extent of the work. Under the Building Act 2004, some minor drainage repairs may be exempt from building consent under Schedule 1 of the Act — but the rules can be complex and vary depending on your local council.
As a general guide:
| Type of Work | Consent Likely Required? |
|---|---|
| Like-for-like repair of a short section of drain | Often exempt (confirm with council) |
| Replacing a significant length of drain | Likely yes |
| Altering drain layout or adding new connections | Yes |
| Work near a public sewer connection | Yes — also involves your council or Watercare |
Always check with your local council before work begins. Do not assume work is exempt. The MBIE Building Performance website has useful guidance on what requires consent.
Even where consent is not required, the work must still be carried out by a licensed drainlayer and must comply with the NZ Building Code (in particular Clause G13 – Foul Water and Clause E1 – Surface Water for stormwater drains) and relevant standards such as NZS 4404 and AS/NZS 3500.
Why Does This Matter?
Hiring an unlicensed person to replace drain pipes carries real risks:
- Legal liability – unlicensed restricted work is an offence under NZ law.
- Insurance issues – your home insurance may not cover damage resulting from unlicensed work.
- Health risks – faulty drains can cause sewage contamination, which is a serious public health hazard.
- Resale problems – unpermitted or uncertified work can complicate future property sales.
For rental properties, landlords also have obligations under the Healthy Homes Standards to maintain drainage in good working order.
How to Check If a Tradesperson Is Licensed
You can verify whether a drainlayer holds a current licence by searching the PGDB licence register. Always ask to see a tradesperson's licence before work begins, and make sure they provide a Certificate of Compliance once restricted work is completed.
When to Call a Professional
If a drain inspection reveals broken, cracked, or collapsed pipes, stop and call a licensed drainlayer or certifying drainlayer straight away. Do not attempt to repair or replace pipework yourself, and do not allow an unlicensed drain cleaner to do so either — regardless of how confident they seem.
For urgent situations such as sewage backing up into your home, contact a licensed plumber or drainlayer immediately, as this can pose a serious health risk.
You can find qualified, licensed drain and plumbing professionals in your area at tradedirectory.co.nz.
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