What Trade Do I Need for a Leaking Roof?

A leaking roof is one of those problems that demands prompt attention — left unchecked, water ingress can damage insulation, framing, linings, and even create mould and structural issues. In most cases, the answer is a qualified roofer, but depending on the cause and extent of the damage, other trades may also be needed. This guide walks you through exactly what to expect.

The Right Trade: Start With a Roofer

A roofer is the primary trade you need for a leaking roof. They have the training, tools, and experience to handle this type of work safely and effectively — from diagnosing the source of the leak through to completing the repair or replacement. In New Zealand, roofing work sits within the broader construction trades, and while roofing is not a licensed restricted trade in the same way that electrical or plumbing work is, a qualified and experienced roofer is essential for safe, weathertight, and compliant results.

When choosing a roofer, look for:

• Membership of the Roofing Association of New Zealand (RANZ) — members agree to a code of practice and have access to ongoing training.
• A Licensed Building Practitioner (LBP) — if the work involves restricted building work (RBW), such as significant structural repairs or re-roofing that affects the weathertightness of the building, the work must be carried out or supervised by an LBP. Always confirm with your roofer and your local council whether your job qualifies as RBW.
• Proof of public liability insurance — ask before work begins.
• References and photos of recent local work — NZ conditions vary enormously between Northland and Southland, and coastal versus inland sites.

What a Roofer Will Do

A roofer will assess the situation, diagnose the cause, and recommend the best course of action. They will provide a quote for the work before starting. A thorough assessment typically includes:

1. Visual inspection from the ground and on the roof itself.
2. Identifying the leak source — this is often not directly above where water appears inside, as water can travel along rafters or sarking before dripping.
3. Checking flashings, valleys, penetrations (skylights, pipes, vents), ridgelines, and gutters.
4. Assessing the roofing material — whether it is long-run steel (e.g. Colorsteel), concrete or clay tiles, butyl membrane, or another system.
5. Recommending repair or replacement — sometimes a targeted repair is all that's needed; other times, widespread corrosion or tile failure means a full re-roof is more cost-effective.
6. Providing a written quote — always get this in writing before work starts, and ideally get multiple quotes to compare scope and price.

NZ-Specific Factors That Affect Roofing

New Zealand's climate creates some specific challenges:

• High UV — particularly in the North Island and at altitude, UV degrades sealants, membranes, and paint coatings faster than in many other countries.
• Coastal salt air — accelerates corrosion on metal roofing and fixings. Coastal properties need roofing materials and fixings rated for the exposure zone.
• Wind and driven rain — especially in Wellington, Manawatū, and exposed South Island locations, wind-driven rain can force water under flashings or tiles that would otherwise be watertight.
• Freeze-thaw cycles — in Central Otago, Mackenzie Basin, and alpine areas, water that gets under tiles or into cracks can expand when it freezes, worsening damage over winter.

These factors mean a roofer with local experience is genuinely valuable — what works in Auckland may not be the right solution in Dunedin.

Could Other Trades Be Involved?

Sometimes a job involves multiple trades. Your primary tradesperson can advise if other specialists are needed. Common situations where additional trades are required include:

If water has reached electrical fittings, ceiling fans, or downlights, stop using those fittings immediately and call a registered electrician before anything else. Electrical work in NZ is restricted work that must be carried out by a registered electrician under the Electrical Workers Registration Board (EWRB) — this is a legal requirement, not just a recommendation.

Consent and Compliance

Many roof repairs — such as replacing a few broken tiles or resealing a flashing — are minor maintenance and do not require a building consent. However, more significant work may require consent, including:

• Full re-roofing that changes the roofing material or profile.
• Structural repairs to rafters or roof framing.
• Adding or relocating skylights or roof penetrations.

Building consent requirements are set out under the Building Act 2004, and Schedule 1 of that Act lists certain exemptions. Always confirm with your local council whether your specific job needs a consent before work begins — do not rely solely on your contractor's advice on this point. The MBIE Building Performance website is a good starting point for understanding consent requirements.

Where restricted building work is involved, your LBP must provide a Record of Work on completion.

DIY vs. Professional

It can be tempting to get on the roof yourself, but roofing is one of the higher-risk DIY tasks:

• Falls from roofs are a leading cause of serious injury and death in NZ — WorkSafe NZ has clear guidance on working at height.
• Incorrect repairs can void manufacturer warranties on roofing materials and create new leak paths.
• If the work constitutes restricted building work and is done without an LBP, you may have difficulty selling the property later.

For anything beyond clearing a blocked gutter from a safely positioned ladder, engaging a qualified roofer is strongly recommended.

When to Call a Professional

Call a roofer promptly if you notice:

• Water stains or drips appearing on ceilings or walls after rain.
• Lifted, cracked, or missing tiles or sheets visible from the ground.
• Rust streaks running down exterior walls from the roofline.
• Sagging or soft spots in the ceiling — these can indicate significant water accumulation.
• Musty smells in the ceiling space, which may indicate ongoing moisture and mould growth.

Don't wait — water damage compounds quickly, and what starts as a minor repair can become a major structural issue if left. Search for qualified local roofers on tradedirectory.co.nz and always get multiple written quotes before committing.

Sources & Further Reading

• MBIE Building Performance — Building Consents
• Licensed Building Practitioners (LBP)
• WorkSafe NZ — Working at Height
• BRANZ — Building Research
• Electrical Workers Registration Board (EWRB)