What Is a Thermal Break, and Do You Need One in Perth?

When building or insulating a home, shed, or commercial space in Western Australia, one term you’ll hear is thermal break. But what exactly does it mean—and is it necessary in Perth’s unique climate?

Let’s explore what thermal breaks do, why they matter in construction, and when you should include them in your insulation strategy.

What Is a Thermal Break?

A thermal break is a material placed between conductive surfaces—typically metal framing and external cladding—to reduce heat transfer. Without a thermal break, heat can travel directly through your structure’s frame, bypassing insulation entirely.

Think of it as a buffer zone: it separates materials that would otherwise act like a heat bridge. In Perth, where summer temperatures can soar above 40°C, this is especially important for maintaining comfort and energy efficiency.

Where Are Thermal Breaks Used?

• Metal-framed walls – A thermal break is mandatory under NCC requirements when using metal framing and external cladding.
• Steel roof systems – Thermal break insulation can be laid under metal roofing to stop radiant heat from entering the ceiling cavity.
• Sheds and outbuildings – Steel sheds and Colorbond-clad studios benefit significantly from adding a thermal break layer.

Why They Matter in Perth

In warm climates like Perth, most energy loss comes from radiant heat entering through the roof and walls. If there’s no thermal break between cladding and structure, traditional insulation is compromised. You’ll notice:

• Hotter indoor temperatures
• Increased air conditioning use
• Lower insulation performance overall

Best Thermal Break Product for WA Projects

Our top recommendation is ThermalBreak 7, a 7mm extra heavy-duty foil-faced insulation that complies with NCC 2019 Section J requirements. It provides both a thermal break and radiant barrier in one product.

• Meets the minimum R-value requirement of R0.2 for thermal breaks
• Highly durable and compliant with Australian construction codes
• Easy to install under metal roofing or behind wall cladding

Complementary Products to Use

Thermal breaks are often used alongside:

• Wall Wraps – Adds an additional moisture and radiant barrier behind cladding.
• Cavity Wall Insulation – Used between studs or battens for thermal performance.
• R-Value Reference Guide – Understand thermal performance benchmarks.

Do You Always Need a Thermal Break?

If you’re building with timber studs and brick veneer, thermal breaks are less essential. But in any metal-framed or metal-clad build, the National Construction Code requires a thermal break to prevent thermal bridging.

If you’re converting a shed, building a new studio, or retrofitting an outbuilding in Perth, adding a product like ThermalBreak 7 can dramatically improve insulation performance.

Conclusion: Small Product, Big Difference

Don’t overlook thermal breaks when insulating metal buildings in Perth. They may be thin, but they make a major difference in comfort and compliance.

Need help figuring out if your project needs one? Give us a call on 0417 910 326 or browse our full range of insulation products online.