Detecting Leaky Homes in NZ: How Thermal Imaging Helps Spot Issues in Monolithic Cladding

New Zealand's building history has been significantly impacted by the "leaky homes" crisis, particularly during the 1990s and early 2000s. Many of these problematic dwellings feature monolithic cladding systems and were constructed during a period when building codes and oversight were insufficient to ensure weathertightness. As a result, moisture ingress and long-term structural damage have plagued thousands of properties across the country. Today, thermal imaging technology plays a key role in non-invasively identifying hidden issues in these homes. This blog explores what monolithic cladding is, why it's problematic, and how thermal imaging can be used to detect potential leaky home risks.

What is Monolithic Cladding? Monolithic cladding refers to a type of solid, continuous exterior wall surface that includes systems such as:

• Stucco plaster

• Fibre-cement sheets (e.g., Harditex)

• EIFS (Exterior Insulation and Finish Systems)

These systems were often installed without sufficient cavity systems or ventilation, allowing moisture to become trapped behind the cladding. When water gets in and can’t escape, the framing timber (often untreated) is at risk of rot, mould, and significant decay.

Direct Fixed vs. Cavity Systems One of the most important distinctions in cladding systems is whether the cladding is direct fixed or installed over a cavity.

• Direct Fixed: The cladding is attached directly to the building paper or wrap over the timber framing. If water penetrates the outer surface, it has nowhere to go and can soak into the framing. This is a common feature in leaky buildings.

• Cavity System: Introduced as part of building code reforms post-2004, cavity systems create a gap between the cladding and the framing using battens or spacers. This gap allows moisture to drain and air to circulate, significantly improving the wall's ability to dry out and resist decay.

Homes with cavity systems are far less prone to long-term damage from moisture ingress. Identifying whether a monolithic home is direct fixed or cavity-based is a crucial part of assessing risk.

The Leaky Homes Crisis in New Zealand Between the mid-1990s and early 2000s, New Zealand experienced a wave of residential construction that prioritised appearance and cost-efficiency over robust weatherproofing. The result was a widespread problem affecting thousands of homes, especially those with monolithic cladding. Some of the key contributors to the crisis included:

• Lack of cavities or drainage systems behind cladding

• Poor flashing installation around windows and doors

• Use of untreated timber framing

• Inadequate roof eaves or overhangs

• Design trends promoting complex rooflines and minimal protection from rain

While building code reforms have significantly improved construction standards since 2004, many homes built prior to these changes are still in circulation and remain a risk for buyers.

How Thermal Imaging Helps Thermal imaging (infrared thermography) is a non-invasive technique that detects temperature variations on surfaces. In building inspections, it can be used to identify potential moisture intrusion by locating cooler, damp areas behind walls and cladding systems.

Key Benefits of Thermal Imaging in Leaky Homes:

• Non-destructive: No need to cut into walls or remove cladding

• Fast and effective: Areas of concern are identified in real time

• Guides targeted repairs: Helps focus invasive testing or remediation only where needed

• Supports negotiation and decision-making: Buyers can use thermal reports to negotiate repairs or reconsider purchases

  
  

What a Thermal Inspection Can Reveal:

• Cold spots consistent with moisture presence

• Areas where insulation may be missing or compromised

• Differences in surface temperature that indicate trapped water or air leaks

It is important to note that thermal imaging should be performed by a certified thermographer and interpreted correctly. It is not a guarantee or substitute for invasive testing, but it is an invaluable tool in the early detection process.

When to Consider a Thermal Imaging Inspection:

• Buying a home built between 1990 and 2004

• Any property with monolithic cladding

• Signs of cracking, staining, or mould inside

• Previous repairs or known weathertightness claims

• Peace of mind before selling or purchasing

  
  

The legacy of New Zealand's leaky homes crisis still lingers in many properties across the country. For homebuyers, homeowners, and investors, understanding the risks associated with monolithic cladding and using advanced tools like thermal imaging is critical to making informed, confident property decisions. When used by qualified professionals, thermal imaging provides a fast, non-invasive way to assess hidden risks and protect yourself from unexpected repair costs.

Book a Thermal Inspection Today If you’re concerned about a property’s cladding or weathertightness, book a thermal imaging inspection with our certified team. We’ll help you see what’s beneath the surface—before it becomes a costly problem.

Thermal Imaging for Buildings in Queenstown-Lakes and Wanaka Region