Yes, a waterproofer can legally subcontract your job to another tradesperson in New Zealand — but this comes with important conditions around licensing, quality, and your rights as the homeowner. Understanding how subcontracting works will help you stay in control of your project and avoid nasty surprises.
What Is Subcontracting?
Subcontracting is when the tradesperson you hire (the principal contractor) brings in another tradesperson or company to carry out some or all of the work on your behalf. This is common practice in the building and construction industry, particularly on larger or more complex projects. The principal contractor remains responsible to you for the quality and completion of the work, even when a subcontractor does the physical job.
Is It Legal in New Zealand?
Yes — subcontracting is entirely legal in NZ, provided the work is carried out by suitably qualified people. There is no law that prevents a waterproofing contractor from delegating work to a subcontractor. However, the key legal obligations depend on the type of work involved.
Waterproofing often falls under restricted building work (RBW) when it relates to the weathertightness of a home — for example, waterproofing a deck, balcony, or wet area that is part of the building envelope. Under the NZ Building Code, work that affects weathertightness must be carried out or supervised by a Licensed Building Practitioner (LBP). This applies whether the work is done by the principal contractor or a subcontractor.
You can verify LBP status at any time through the Licensed Building Practitioners register.
When Does Waterproofing Require an LBP?
Not all waterproofing is restricted building work. Here's a general guide:
| Type of Waterproofing | Likely RBW? | LBP Required? |
|---|---|---|
| Exterior deck or balcony membrane | Yes | Yes |
| Wet area (bathroom/laundry) in a house | Depends on scope | Check with your council |
| Basement tanking | Depends on scope | Check with your council |
| Swimming pool surrounds | Generally no | No, but skill required |
| Retaining wall drainage | Depends | Check with your council |
Always confirm with your local council whether a building consent is required before work begins. Some waterproofing work may be exempt under Schedule 1 of the Building Act, but exemptions have limits — your council is the right authority to advise you.
Your Rights When Work Is Subcontracted
As a homeowner, you have several important rights:
- Right to know: You can ask your contractor upfront whether they intend to subcontract any part of the work, and who the subcontractor will be.
- Right to check credentials: You can request the subcontractor's LBP licence number or other relevant qualifications before work starts.
- Contractual protection: Your contract is with the principal contractor. If the subcontractor's work is defective, your legal claim is against the person or company you hired — not the subcontractor directly.
- Consumer guarantees: Under the Consumer Guarantees Act, services must be carried out with reasonable care and skill. This applies regardless of whether a subcontractor does the work.
Consumer NZ has useful guidance on your rights when hiring tradespeople.
What to Put in Your Contract
Before any waterproofing work begins, make sure your written contract (or quote) covers:
- Whether subcontracting is permitted and who will be used
- Licence numbers of all LBPs involved
- Warranty terms — who backs the workmanship warranty if a subcontractor does the work?
- Product specifications — quality waterproofing membranes from reputable suppliers matter; products from brands like Sika or Ardex are widely used in NZ
- Completion timeline and who is responsible for delays
Get everything in writing before work starts. A verbal agreement is much harder to enforce.
Quality and Compliance Considerations
Waterproofing is one of the most critical elements of a building's performance. Poor waterproofing is a leading cause of weathertightness failures — a costly problem that has affected many NZ homes. BRANZ provides research and guidance on best-practice waterproofing methods that any competent contractor or subcontractor should follow.
For wet areas, compliance with the relevant NZ Standard for wet area membranes is important — confirm the applicable standard with your contractor or council. Exterior waterproofing must meet the requirements of Clause E2 (External Moisture) of the NZ Building Code. Make sure whoever does the work — contractor or subcontractor — is familiar with these standards.
When to Call a Professional
Waterproofing that affects the weathertightness or structural integrity of your home should always be carried out by a qualified professional. If the work is restricted building work, an LBP must be involved — it's not optional. Even for work that isn't technically restricted, the consequences of getting it wrong are expensive, so this is not an area to cut corners.
If you're unsure whether the person turning up to do your job is properly qualified, ask to see their LBP card or ask your contractor to confirm in writing. You can find qualified, vetted waterproofing professionals in your area right here on tradedirectory.co.nz.
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