Water dripping or staining through your ceiling is one of those problems that demands immediate attention — left unchecked, it can cause serious structural damage, mould growth, and costly repairs. In most cases, the first trade you need to call is a qualified plumber, but depending on the source of the leak, a roofer, builder, or even an electrician may also need to be involved. This guide walks you through how to identify the likely cause, which trade to contact, and what to expect from the process.
Why a Plumber Is Usually Your First Call
A plumber is the primary trade for water coming through a ceiling because the most common causes — burst or leaking pipes, failed hot water cylinder connections, leaking shower trays, and overflowing baths or toilets on an upper floor — all fall squarely within their scope of work. Plumbers are trained to diagnose water ingress, trace the source (which is often not directly above the visible wet patch), and carry out repairs safely.
In New Zealand, certain plumbing work is restricted work under the Plumbers, Gasfitters and Drainlayers Act 2006. This means it must be carried out by, or under the supervision of, a licensed craftsperson registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB). Connecting, disconnecting, or repairing any sanitary plumbing or water supply pipework is restricted — you cannot legally do this yourself. Always ask to see your plumber's current PGDB licence before work begins.
Common Causes of Water Through a Ceiling
Understanding the likely source helps you describe the problem clearly when you call a tradesperson:
- Leaking pipe or fitting — a burst, corroded, or poorly joined pipe in the ceiling cavity or wall
- Failed shower or bath waterproofing — water escaping through cracked grout, failed silicone, or a deteriorated membrane in a wet area above
- Overflowing or blocked drain — a blocked waste pipe causing water to back up and overflow
- Hot water cylinder or heat pump water heater — a leaking cylinder, pressure relief valve, or associated pipework
- Roof leak — rainwater entering through damaged roofing, failed flashings, or blocked gutters and finding its way to your ceiling
- Condensation — in some cases, particularly in poorly ventilated roof spaces, condensation can drip and mimic a leak
- Appliance connections — a leaking dishwasher, washing machine, or fridge icemaker on an upper floor
Which Trade Do You Actually Need?
The table below gives a quick guide, though a plumber can usually help you confirm the source:
| Likely Cause | Primary Trade | Possible Additional Trade |
|---|---|---|
| Leaking pipe or fitting | Plumber | Builder (if linings need repair) |
| Failed shower/bath waterproofing | Plumber or tiler | Builder, plasterer |
| Blocked or overflowing drain | Plumber/drainlayer | — |
| Hot water cylinder leak | Plumber | Electrician (if electric HWC) |
| Roof leak or failed flashing | Roofer | Builder, plasterer |
| Condensation in roof space | Builder or insulation specialist | — |
| Appliance connection | Plumber | Appliance technician |
What a Plumber Will Do
When you call a plumber, they will:
- Assess the situation — visually inspect the wet area, check for obvious signs of the source, and ask about recent events (heavy rain, appliance use, etc.)
- Diagnose the cause — this may involve accessing the ceiling cavity, using moisture meters, or running water through fixtures to reproduce the leak
- Recommend a course of action — they will explain what needs to be done and whether other trades are required
- Provide a quote — a reputable plumber will give you a written quote before starting work
- Carry out restricted work — all sanitary and water supply repairs will be completed to the NZ Building Code standards, particularly clause G12 (water supplies) and clause G13 (foul water)
- Issue a compliance certificate — for restricted plumbing work, your plumber must issue a Certificate of Compliance on completion
Could Other Trades Be Involved?
Yes — and your primary tradesperson will advise you if specialists are needed. Common scenarios include:
- Roofer: If the plumber determines the water is entering from outside through the roof or flashings, a qualified roofer is the right person to fix it. Roof repairs in NZ must comply with NZ Building Code clause E2 (external moisture).
- Builder or Licensed Building Practitioner (LBP): Once the leak is fixed, damaged ceiling linings, framing, or insulation will need repair. Structural or weathertightness work may require a Licensed Building Practitioner.
- Plasterer: Replacing damaged GIB or skim-coating a repaired ceiling is typically a plasterer's job.
- Electrician: If water has reached light fittings, ceiling fans, or wiring — stop using those circuits immediately and call a registered electrician. Electrical work is restricted under the Electricity Act and must be carried out by a registered electrician registered with the Electrical Workers Registration Board (EWRB). Do not attempt to inspect or repair wiring yourself.
- Mould remediation specialist: If the leak has been ongoing, mould may have established in the ceiling cavity. WorkSafe NZ has guidance on managing mould safely.
Do You Need a Building Consent?
Most leak repairs are maintenance work and do not require a building consent. However, if the repair involves replacing a significant area of roofing, altering drainage, or structural work, a consent may be required. Always check with your local council — what qualifies as a Schedule 1 exemption varies. Your plumber or builder can advise, and MBIE Building Performance has useful guidance online.
What to Do Right Now (Before the Tradesperson Arrives)
- Place a bucket under the drip to protect your floor and belongings
- Turn off the water supply at the toby (street valve) or internal stopcock if you suspect a burst pipe
- Switch off the circuit breaker for any affected lights or ceiling fittings — water and electricity are a dangerous combination
- Take photos and video of the damage for insurance purposes
- Contact your insurer — many home insurance policies cover sudden and accidental water damage; your insurer may have preferred tradespeople or a claims process to follow
- Do not attempt to open the ceiling yourself unless you are certain there are no live electrical cables in the area
When to Call a Professional
Always call a licensed professional for water coming through your ceiling. This is not a DIY situation for several reasons:
- Plumbing repairs to sanitary or water supply systems are legally restricted work in New Zealand
- Water damage can compromise structural framing and insulation in ways that are not visible
- Mould can establish within 24–48 hours in wet conditions
- Water near electrical wiring or fittings creates a serious electrocution risk
A qualified local plumber, roofer, or builder can be found quickly on tradedirectory.co.nz. Always get at least two or three written quotes, check that your tradesperson holds a current licence (PGDB for plumbers, LBP for builders), and ask for a Certificate of Compliance on completion of any restricted plumbing work.
Sources & Further Reading
- Plumbers, Gasfitters and Drainlayers Board (PGDB) — licence verification
- MBIE Building Performance — NZ Building Code and consents
- Licensed Building Practitioners — find and verify an LBP
- Electrical Workers Registration Board — verify an electrician
- BRANZ — building research and moisture guidance
- WorkSafe NZ — mould and health in buildings
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