ATI Cavi-Break®
Cavi-Break is a thermal break cavity batten that installs between external framing and cladding, reducing heat transfer through steel and creating a defined cavity for condensation management on timber. Paired with Cavi-Vent, the two form a complete wall system.
- Outperforms the NCC minimum thermal break requirement by 40% to 350%, with R-values from R0.28 (X10) to R0.90 (X35).
- Designed to benefit both steel and timber framing, functioning as a thermal break and cavity batten in a single product.
- Self-adhesive backing means no power tools and no extra fixings for placement.
- High compressive strength maintains cavity depth and straight cladding lines under load.
- Cut to length on site with standard hand tools.
Technical information
All ATI products are manufactured from XPS that does not absorb moisture, rot, swell or twist. Once installed, they maintain thermal separation and cavity depth passively with no maintenance required. Minimum 50-year lifespan.
Major cladding manufacturers recommend or require a defined cavity behind their products to support drainage and ventilation. Cavi-Break and Cavi-Vent create that cavity depth while providing thermal separation at the framing interface, making it easier to align with cladding manufacturer installation requirements and support warranty conditions.
All ATI wall products are compatible with both steel and timber framing across residential and commercial wall assemblies. For steel-framed construction, they outperform the NCC thermal break requirement. For timber-framed construction, they create a defined cavity that supports condensation management as standards continue to tighten.
Cavi-Break and Cavi-Vent are supplied in 1,200mm lengths to align with standard framing layouts without cutting in most applications. Reduces waste on site and cuts to length with standard hand tools where needed.
All ATI wall products feature self-adhesive backing that holds the strip in place over the wall wrap or membrane while cladding is fixed through into framing as normal. No power tools, no extra fixings, straightforward enough for a single installer.
Cavi-Break and Cavi-Vent are manufactured from high-density extruded polystyrene (XPS) with high compressive strength to resist deformation under cladding loads. Maintaining dimensional stability is critical for two reasons: it keeps cladding lines straight and preserves the defined cavity depth over the service life of the building. Unlike lower-density foam products, they do not compress or creep under sustained load.
NCC Part 13.2.5 requires a minimum R0.2 thermal break between steel framing and external cladding in steel-framed construction. Independent test data referenced to AS/NZS 4859.1 is available to support compliance documentation and Energy Efficiency Aspect certification.
Cavi-Break and Cavi-Vent are each available in four independently tested R-values: R0.28 (X10), R0.34 (X12), R0.58 (X20) and R0.90 (X35). All variants outperform the NCC Part 13.2.5 minimum thermal break requirement of R0.2 for steel-framed construction, starting at 40% above the minimum. Higher R-values contribute more significantly to Total Wall R-Value, supporting stronger energy efficiency outcomes without increasing wall depth.
ATI packaging is designed with the job site in mind. Each carton features a tear-away strip for easy opening and a QR code giving immediate access to installation instructions. The self-adhesive product is kept clean and off the ground within the carton, and backing tape waste can be disposed of in the carton lid, reducing mess and keeping the site tidy during installation.
NatHERS software has expanded the allowable thermal break input range to R1.0, up from R0.5. This allows Cavi-Break variants including the X35 (R0.90) to be accurately represented in energy modelling. Entering tested R-values into NatHERS calculations gives designers and energy assessors a more accurate picture of wall performance, which can provide greater flexibility when balancing insulation levels and glazing ratios to meet 7-Star targets.
The Total Wall R-Value reflects the combined thermal resistance of all components in a wall assembly, including framing, insulation, cladding and thermal breaks. Upgrading from a standard R0.2 thermal break to Cavi-Break X20 can increase Total Wall R-Value by approximately 23 to 24 per cent in a typical lightweight framed wall. This can allow a step-down in batt insulation specification without sacrificing overall wall performance.
Thermal bridging occurs when a conductive material creates a direct path for heat to bypass insulation. In framed wall construction, steel and timber studs conduct heat and cold through the wall regardless of how much batt insulation sits between them. Cavi-Break reduces this by placing a continuous layer of low-conductivity material between the framing and the cladding, breaking that conductive path at the framing interface.
Relevant downloads
Product benefits
ATI products are designed with the working site in mind, not just the lab. It installs simply and consistently, without complex detailing or improvised workarounds. The result is a repeatable process that’s faster than traditional batten methods.
Meeting NCC requirements shouldn't require guesswork. Cavi-Break is independently tested to Australian standards with full documentation to support compliance.
Not every wall build-up is the same. Cavi-Break is available in multiple thicknesses, whether you need to match an existing cavity depth or step up your Total Wall R-Value for stronger 7-Star outcomes.
Cavi-Break is built to perform across the life of the building, not just at handover. Dimensional stability under load, tested R-values and compatibility with major cladding manufacturer guidance are built in from the start. That means fewer callbacks and drier walls for the long term.
Frequently asked questions
In many cases, yes. Independently calculated wall system R-values for Cavi-Break X20 strips on steel framing with R2.0 batts outperform competitor systems using R2.7 batts. That means builders may be able to step down their batt insulation specification without sacrificing thermal performance, with potential savings of around $2,000 to $2,500 per home on insulation alone.
Yes. Both products are compatible with steel and timber framing across residential and commercial applications. On steel frames they provide thermal break performance to exceed NCC requirements. On timber frames they create a defined cavity for condensation management.
Cavi-Break reduces cold bridging through framing members, a primary cause of condensation forming within wall systems. When paired with Cavi-Vent, the two products together address both thermal separation and moisture management, going well beyond minimum code requirements.
No. Cavi-Break integrates within conventional lightweight wall build-ups without increasing overall wall thickness or requiring fundamental redesign. Cavity depth is defined by the product profile, and thermal separation is achieved at the cladding interface rather than within the framing zone.
Yes. Several major cladding manufacturers recommend or require a drained and ventilated cavity behind their products, and some limit warranty coverage for condensation and mould damage where no cavity is provided. Cavi-Vent helps builders meet those conditions, reducing the risk of warranty disputes and callbacks well after handover.
Yes. All ATI products are manufactured from high-density XPS that does not absorb moisture, rot, swell or twist. Each product is designed with a minimum 50-year lifespan. Once installed, they work passively with no maintenance required.
No. Vapour control strategy remains dependent on climate zone, building use and overall wall design under NCC and AS 4200.2 requirements. ATI products work alongside, not instead of, membrane and vapour control elements in the wall build-up.
In most wall systems, yes. Cavi-Break is applied vertically over studs to provide continuous thermal separation, while Cavi-Vent is applied horizontally to form a drained and ventilated cavity behind cladding. Used together, they deliver a complete wall system without requiring additional components or complex detailing.
Condensation management and thermal performance must be demonstrated through documentation, including the Energy Efficiency Aspect Certificate (Form 43). A defined thermal break and drained cavity system makes it easier to demonstrate compliance at handover.
No. Strips are supplied in 1,200mm lengths for easy handling and alignment with typical framing layouts. The self-adhesive backing holds the strip in place while cladding is fixed through it. No H3 treated timber, no treating of cut ends, no pre-fixing battens. Installation is typically at least 30 per cent faster and straightforward enough for a single installer, apprentice included.
A thermal break reduces heat transfer through framing members, which are natural weak points in a wall's thermal performance. Without one, the frame itself conducts heat and cold regardless of how much insulation is installed between studs. For steel-framed construction, NCC Part 13.2.5 requires a minimum R0.2 thermal break. Cavi-Break starts at 40% above that requirement at its thinnest variant.
Both Cavi-Break and Cavi-Vent are available in four tested configurations: X10 (R0.28), X12 (R0.34), X20 (R0.58) and X35 (R0.90). For Cavi-Vent, the X12 variant is specifically relevant where a defined 12mm drained and ventilated cavity is required under NCC 2025 in Climate Zones 6, 7 and 8. For Joist-Break Ultra, two variants are available: Ultra10 and Ultra20.
Product brochures and installation guidance are available in the Resources section. For specifiers requiring tested R-value data, compliance documentation or energy modelling notes, a Specifier Pack is available upon request.
All ATI products are available through ATI's reseller and stockist network. Find your nearest stockist on the Where to Buy page, or contact ATI directly if you need help identifying the right supplier for your project.
No. Both Cavi-Break and Cavi-Vent are manufactured from high compressive strength XPS engineered to resist deformation under typical lightweight cladding loads. Dimensional stability is maintained across the service life of the building, preserving cavity geometry and straight cladding lines.
Yes, meaningfully. In a typical lightweight framed wall, upgrading from a standard R0.2 thermal break to Cavi-Break X20 can increase Total Wall R-Value by approximately 23 to 24 per cent. That supports stronger 7-Star outcomes without increasing wall depth or changing the fundamental build-up.
