Advanced Slab Edge Details for Termite Management in Steel Frame Kit Homes

Introduction

Welcome, advanced owner-builders, to this comprehensive treatise on slab edge detailing for termite management in Australian steel frame kit homes. As an experienced owner-builder, you understand that building in Australia presents unique challenges, not least among them being the pervasive threat of subterranean termites. These insidious pests can compromise the structural integrity and value of your most significant investment. While steel framing, particularly products like TRUECORE® by BlueScope Steel, offers inherent resistance to termite attack compared to timber, the non-timber elements of your home – such as plasterboard, timber architraves, door frames, and internal fit-outs – remain highly susceptible. Consequently, robust termite management is not merely a recommendation; it is a mandatory, non-negotiable component of Australian building compliance.

This guide is designed for the discerning owner-builder seeking an advanced understanding of the regulatory landscape, engineering principles, and practical application of slab edge termite barriers. We will delve deeply into the National Construction Code (NCC) requirements, relevant Australian Standards, and state-specific nuances that govern effective termite management. Our focus will be squarely on the integration of physical termite barriers at the slab edge, a critical juncture often overlooked or inadequately addressed, yet fundamental to preventing concealed termite entry. We'll explore various methodologies, material specifications, and installation techniques, providing the granular detail necessary for you to oversee, specify, or even execute these vital components with confidence and precision. By the culmination of this guide, you will possess the expert-level knowledge required to ensure your steel frame kit home is not only structurally sound but also comprehensively protected against Australia's most formidable natural destructor, securing its longevity and your peace of mind.

Understanding the Basics: Termite Biology, Risk, and Management Philosophy

To effectively combat termites, an advanced owner-builder must first understand their adversary. Subterranean termites (e.g., Coptotermes acinaciformis, Schedorhinotermes intermedius, Mastotermes darwiniensis) are eusocial insects living in complex colonies. Their primary sustenance is cellulose, found abundantly in wood and plant-derived materials. They operate primarily underground, creating intricate tunnel systems to forage for food, which allows them to bypass traditional timber structures entirely unseen. Their entry into a building is typically concealed, often through service penetrations, cracks in slabs, or, critically, via unprotected slab edges.

Australia is considered one of the most termite-prone countries globally. The CSIRO estimates that one in three homes will be affected by termites at some point, causing hundreds of millions of dollars in damage annually. The risk varies geographically, with tropical and subtropical regions (e.g., coastal QLD, NSW) experiencing higher activity, but no region is entirely immune. Even in southern states, microclimates and existing colonies can pose significant threats.

The philosophy behind effective termite management, as enshrined in the NCC and AS 3660, is multi-faceted, focusing on detection and prevention of concealed entry. While chemical soil treatments were historically prevalent, the trend has shifted towards durable physical barriers, especially for new construction. Physical barriers, when correctly installed, offer a non-toxic, long-lasting solution, creating an impenetrable layer around the building's perimeter and at critical entry points.

For steel frame kit homes, the advantage of steel (e.g., TRUECORE® steel) is its non-cellulose composition, rendering it impervious to termite consumption. However, this inherent resistance can sometimes foster a false sense of security. Termites will not eat the steel frame itself, but they will readily tunnel around it to access plasterboard, skirting boards, timber flooring, cabinetry, roof timbers, and even electrical wiring insulation. The key is to prevent their entry into the concealed spaces within the building envelope. This is where slab edge detailing becomes paramount. A properly detailed slab edge, combined with other barriers, forms a comprehensive protective shell, denying termites the hidden pathways they exploit.

Australian Regulatory Framework: NCC, AS 3660, and State Specifics

Navigating Australia's building regulations requires a deep understanding of the interlocking requirements of the National Construction Code (NCC) and various Australian Standards. For termite management, the primary reference documents are NCC Volume Two (for housing and small residential buildings, specifically Class 1 and 10a buildings) and AS 3660.1, Termite management Part 1: New building work.

NCC Volume Two: Performance and Deemed-to-Satisfy Provisions

NCC 2022, Volume Two, H1P1 (Performance Requirement): "A building must be constructed in a manner that will prevent the penetration of termites where they are known to be a problem, or are likely to be a problem, from the soil into the building, whether by way of subterranean tunnels or otherwise." This is the overarching principle.

NCC 2022, Volume Two, H1D7 (Deemed-to-Satisfy Provisions): This section provides the primary Deemed-to-Satisfy (DtS) pathway for termite management. It states that a building must be protected against subterranean termites in accordance with AS 3660.1. Crucially, it also specifies that physical barriers must be installed so that the barrier, or combination of barriers, extends continuously to provide a complete barrier around the penetrations and perimeter of the building elements most susceptible to subterranean termite attack.

The NCC places the onus on ensuring the chosen termite management system is appropriate for the termite hazard level of the region, which your building certifier will confirm. For owner-builders, understanding H1D7 means that simply stating "termite treatment" is insufficient; you must demonstrate compliance with the specific provisions of AS 3660.1.

AS 3660.1: Termite Management for New Building Work

AS 3660.1 is the cornerstone for physical termite barriers. It details specific requirements for the installation and inspection of various barrier types. For slab edges, the standard focuses on creating a "visual inspection zone" and preventing concealed entry.

AS 3660.1:2014 Clause 5.2.2 (Slab Edges): This clause is critical. It mandates that where slab-on-ground construction is used, the slab edges shall be exposed to allow for visual inspection for termite entry. The exposed perimeter of the slab must be a minimum of 75 mm from finished ground level. This 75 mm exposure is vital; if termites attempt to enter, they must build their mud tunnels over this exposed edge, making their activity visible and allowing for detection and eradication before significant structural damage occurs.

AS 3660.1:2014 Clause 5.3 (Physical Barriers): This section provides specifications for various physical barrier types, including specific material requirements (e.g., stainless steel mesh meeting AS/NZS 3717.1, approved particulate barriers to AS 3660.3, or rigid sheet materials). The key here is the continuity of the barrier. It must be continuous across the entire perimeter and at all penetrations (pipes, conduits, and other services) through the slab.

AS 3660.1:2014 Clause 5.6 (Durability): Physical barriers must have a design life equal to or greater than the design life of the building. This typically means 50 years, which eliminates many older, less durable chemical treatments.

State and Territory Specific Variations

While the NCC and AS 3660.1 provide a national framework, states and territories can introduce specific amendments or interpretations through their respective building regulations. Owner-builders must consult these local legislative instruments.

• NSW (New South Wales): Administered by NSW Fair Trading. The Environmental Planning and Assessment Regulation 2021 refers to the NCC. No significant variations to AS 3660.1 are common for slab edges, but stringent certification and inspection regimes are in place. Owners-builders often engage Private Certifiers (PCs) who will focus heavily on photographic evidence of barrier installation and continuity.
• QLD (Queensland): Administered by the Queensland Building and Construction Commission (QBCC). The Queensland Development Code (QDC) MP 1.1 Design and Siting, Part A1 Termite Protection often reinforces NCC and AS 3660.1 requirements. High termite pressure in QLD means building certifiers are exceptionally vigilant. Specific attention is paid to articulation joints and other potential breach points in the slab.
• VIC (Victoria): Administered by the Victorian Building Authority (VBA). The Building Regulations 2018 adopt the NCC. Victoria generally follows AS 3660.1 closely. Emphasises on visual inspection zones for all new builds. Owner-builders need to be aware of permit conditions that might specify particular barrier types in certain high-risk areas.
• WA (Western Australia): Administered by the Building Commission (part of the Department of Mines, Industry Regulation and Safety). The Building Regulations 2012 adopt the NCC. WA often has higher requirements for termite resistance due to the presence of Mastotermes darwiniensis in northern regions, which are particularly destructive. While slab edge details remain consistent with AS 3660.1, the overall termite management strategy may be more prescriptive.
• SA (South Australia): Administered by Consumer and Business Services (CBS). The Planning, Development and Infrastructure (Building) Regulations 2019 reference the NCC. South Australia generally adheres to AS 3660.1. Owner-builders should confirm local council requirements for termite management system certificates.
• TAS (Tasmania): Administered by Consumer, Building and Occupational Services (CBOS). The Building Act 2016 and Building Regulations 2016 adopt the NCC. Tasmania, having lower overall termite risk, might sometimes have less stringent enforcement for some aspects, but the slab edge exposure requirement of 75mm always applies unless a full compliant physical barrier is in place to the entire perimeter eliminating the need for a visual inspection zone (e.g., full concrete encasement of a termiticide-impregnated barrier).

Professional Advice: Always engage a local Building Certifier (PC or Council) early in your design phase. They are the ultimate authority on local interpretation and will be signing off on your compliance. Present your chosen termite management system, including detailed slab edge specifications, for pre-approval.

Step-by-Step Process for Integrating Slab Edge Termite Barriers

The integration of effective slab edge termite barriers is a multi-stage process that commences during the foundation design and continues through to post-construction landscaping. For steel frame kit homes, the principles remain consistent, but the need for meticulous planning is heightened due to the prefabricated nature of the frame.

Step 1: Design and Documentation (Pre-Construction)

1. Termite Management Strategy Development:

   • Engage a Professional: Consult with a structural engineer and a licensed pest control operator specialising in physical barriers. Discuss the termite hazard level for your specific site, confirmed by your Building Certifier. Refer to AS 3660.1 Appendix A for guidance on termite hazard levels.
   • System Selection: Choose a compliant physical barrier system for the slab edge. Common options include:
     • Stainless Steel Mesh (e.g., Termimesh, Altis Termite Protection): High-grade, durable mesh. Requires specialist installation.
     • Granular Particulate Barriers (e.g., Granitgard, Termigran): Crushed granite or other inert materials forming a physical deterrent. Requires specific grading and compaction.
     • Sheet Materials (e.g., Termi-Film, Homeguard): Flexible or rigid sheets impregnated with termiticide that also act as a damp-proof course (DPC). Must extend vertically up the slab edge and horizontally under the slab.
   • Integration with Slab Design: Your structural engineer must detail the slab edge to accommodate the chosen barrier. This includes specifying recesses, formwork adjustments, or additional concrete cover requirements. For example, if using an embedded mesh system, this must be shown on the engineering drawings.

2. Council/Certifier Approval:

   • Submit Detailed Plans: Your building application must include detailed architectural and engineering drawings clearly showing the proposed termite management system, specifically the slab edge details. Include product specifications and installation instructions from the barrier manufacturer.
   • Compliance Statement: A statement from the pest control operator or a design certificate verifying that the selected system complies with NCC H1D7 and AS 3660.1 is often required.

Step 2: Site Preparation and Formwork (During Construction)

1. Site Clearance and Leveling: Ensure the building footprint is cleared of all cellulose debris (roots, timber scraps) to a depth of at least 300mm. Termites are attracted to these food sources. The sub-grade must be correctly prepared to achieve specified compaction for the slab. Any backfill used must be free of organic material and compacted to standard (AS 2870, Appendix B).

2. Formwork Setup for Exposed Edge System (75mm Minimum):

   • Accurate Datum: Establish a precise finished floor level (FFL) datum. Your slab edge formwork must be set to ensure a minimum 75mm vertical exposure of the concrete slab edge above the finished ground level (FGL) or paving level, as per AS 3660.1:2014 Clause 5.2.2.
   • Perimeter Scabbing/Rebates: If integrating a physical barrier that needs to extend vertically up the slab edge, consider formwork rebates or scabbing during the pour to create a flush finish for the barrier or to hold it securely. For example, some 'footing' systems incorporate a rebate for a DPC/termite barrier to run into.

Step 3: Barrier Installation (Prior to Slab Pour/During Slab Curing)

This is the most critical phase. The specific steps depend on the chosen barrier type.

Option A: Embedded Physical Barrier (e.g., Stainless Steel Mesh, Sheet Barrier)

1. Under-Slab Barrier (where applicable): If using a full under-slab barrier system (e.g., Termi-Film or Homeguard), it must be laid over the prepared sub-grade, extending beyond the slab footprint to integrate with the slab edge barrier. All overlaps must be sealed as per manufacturer specifications (typically 150mm overlap with proprietary adhesive/tape).

2. Slab Edge Integration:

   • Vertical Extension: The barrier material must extend vertically up the outside face of the slab and be securely fixed. For mesh systems, this involves proprietary clips or ties into the formwork/reinforcement. For sheet barriers, it's typically adhered or bonded to the formwork face. The barrier must extend a minimum of 75mm above the anticipated FGL/paving level, matching the visual inspection zone.
   • Horizontal Return (if required): Some systems require a horizontal return of the barrier material under the slab edge, tying into the under-slab barrier, or extending at least 50mm inwards from the slab edge to create an L-shaped profile. This ensures continuity and prevents termites from tunneling up alongside the internal face of the slab edge.

3. Penetrations: All service penetrations (plumbing pipes, electrical conduits) through the slab must have individual termite collars or boots installed around them before the slab pour. These collars must be mechanically fixed or chemically bonded to the pipe and the surrounding barrier material, creating a sealed, continuous barrier from the pipe to the slab.

Option B: Granular Particulate Barrier (External Perimeter)

1. Trench Preparation: A trench is excavated around the entire perimeter of the slab edge after the slab has cured, typically 300mm deep and 150mm wide. The slab edge must still maintain its 75mm exposed face.

2. Barrier Installation:

   • Geotextile Lining: The trench is lined with a geotextile fabric to prevent intermixing of the particulate barrier with surrounding soil.
   • Particulate Placement: The graded particulate material (e.g., crushed granite) is carefully placed into the trench and compacted in layers to ensure it forms a dense, immovable barrier. The top of the barrier must be flush with the FGL and terminate at least 75mm below the top of the exposed slab edge.

3. Continuous Seal: The particulate barrier must be continuous, with no gaps or bridging. It acts as a physical deterrent that termites cannot tunnel through due to the irregular particle size and density.

Step 4: Post-Slab Pour and Handover

1. Maintain Exposure: After formwork removal, ensure the 75mm exposed slab edge is maintained. No soil, paving, or landscaping materials should bridge this gap. This is crucial for the integrity of the visual inspection zone.

2. Landscaping Considerations: Design your landscaping to prevent bridging. Install garden beds or paving at least 75mm below the slab top. Use non-organic mulches (e.g., gravel, pebbles) within 300mm of the building. Timber retaining walls should be a minimum of 300mm away from the slab edge and ideally treated or naturally termite-resistant.

3. Warranty and Certification: Upon completion, obtain a Certificate of Termite Management from the licensed pest control operator. This certificate, typically valid for 12 months, confirms the installation complies with AS 3660.1 and registers the system. This is a mandatory document for your final Occupation Certificate.

4. Inspection Schedule: Implement an annual termite inspection program with a licensed professional, as recommended by AS 3660.2. Even with physical barriers, regular inspections are vital for early detection of potential breaches or termite activity.

Safety Considerations (WHS)

WHS Note: When working with formwork, concrete, or trenching, always adhere to Safe Work Australia guidelines and state-specific WHS regulations (e.g., NSW WHS Regulation 2017, QLD Work Health and Safety Regulation 2011). Ensure proper trenching safety measures (shoring, egress) if excavating for granular barriers. Wear appropriate PPE, including safety glasses, gloves, steel-capped boots, and high-visibility clothing. If using any chemical components, review Safety Data Sheets (SDS) thoroughly and follow all handling and ventilation instructions.

Practical Considerations for Steel Frame Kit Homes

While steel framing inherently resists termite consumption, the interface between the steel frame, the slab, and external finishes requires meticulous attention in a kit home context. Precision in manufacturing and construction is a hallmark of steel kit homes, and this precision must extend to termite barrier integration.

Integration with TRUECORE® Steel Framing

TRUECORE® steel by BlueScope Steel provides a lightweight, dimensionally stable, and naturally termite-resistant framing solution. However, the steel frame itself sits on either a sole plate or directly on the slab, and it's the junction at the slab edge where vigilance is paramount.

1. Slab and Sole Plate Interface: Traditional timber frame construction often uses a treated timber sole plate. In steel frame construction, the frame typically sits directly on the slab, or on a thin galvanised steel sole plate. The termite barrier must extend under any sole plate to prevent termites from gaining concealed access directly into the wall cavity from the slab. While termites won't eat the sole plate, they will use the concealed space beneath it to gain entry. For concealed barriers, the barrier must continue under the entire wall-floor junction to the internal face of the slab.

2. External Cladding and Concealment: Steel frame kit homes often utilise various external cladding systems (e.g., fibre cement, steel sheeting, composite panels). It is crucial that the chosen cladding system does not bridge the 75mm visual inspection zone at the slab edge. This means the bottom edge of the cladding must terminate at least 75mm above the FGL/paving level. If the cladding must extend lower (e.g., for aesthetic reasons or specific detailing), then the termite management system must be an embedded, continuous physical barrier that protects the entire concealed zone, thereby eliminating the need for the visual inspection zone at that specific location. This is a more complex detail requiring explicit engineering and certifier approval, often involving a continuous sheet barrier fully adhering to the slab edge and lapping into the under-slab membrane, with an inspection zone at a higher level (e.g., above the lower edge of cladding).

3. Articulation Joints and Control Joints: Concrete slabs, especially larger ones, will have articulation or control joints. These are inherent weaknesses where termites can exploit hairline cracks. Any physical termite barrier (e.g., sheet membrane) must be continuous across these joints, accommodating movement without tearing (e.g., by creating a re-entrant corner or using specific flexible sealant/tape over the barrier). If an external, visible slab edge barrier is used, these joints must still maintain their 75mm visual inspection zone.

4. Verandahs, Patios, and Garages: These unheated, Class 10a structures attached to the main Class 1 building also require termite protection. The common approach is to provide a physical termite barrier (e.g., a stainless steel mesh strip or impregnated membrane) at the junction between the Class 1 building and the attached Class 10a slab. This barrier must be continuous with the main building's termite management system. The perimeter of the Class 10a slab itself might also require a 75mm exposed edge, particularly if it abuts landscaping.

Advanced Detailing Tip: For high-end architectural designs where a 75mm exposed concrete edge is deemed unacceptable aesthetically, an alternative compliant solution for concealed slab edges (e.g., continuous external render down to FGL) must be engineered. This typically involves a fully embedded physical barrier (e.g., stainless steel mesh or a durable, termiticide-impregnated sheet barrier) permanently adhered to the slab face, extending a minimum of 75mm below the FGL and integrating seamlessly into the DPC and possibly under-slab membrane. This design eliminates the visual inspection zone at that specific point, relying entirely on the integrity of the concealed barrier. This requires explicit sign-off from the certifier and the termite management system provider, often incurring higher costs due to specialised materials and installation.

Specifics for BlueScope Steel Products

While TRUECORE® steel is termite resistant, the protective coating (ZINCALUME® steel with Activate® technology) is a sacrificial layer to protect the steel from corrosion. Maintaining the integrity of this coating during construction is essential. Termite barrier installation should not compromise this coating. For example, abrasive fixings or chemical adhesives used in conjunction with barriers should be checked for compatibility with the galvanised coating. Generally, the actual steel frame is installed after the slab and its integrated termite barriers are in place, minimising direct interface issues during barrier installation.

Cost and Timeline Expectations

Accurate cost and timeline projections are vital for owner-builders. Termite management, while a small percentage of overall build cost, is not an area to cut corners. Investing in a robust system upfront saves exponentially on potential future remediation.

Cost Estimates (AUD, as of mid-2024)

Costs vary significantly based on location, building size (linear metres of perimeter), system type, and installer expertise. The figures below are indicative for a typical 150-200 sqm home with a perimeter of 50-60 linear metres.

Cost Note: These figures do not include any additional concrete work (e.g., rebates, thicker slab edges for specific systems) or significant earthworks. Always get at least three detailed quotes from licensed and reputable termite management companies.

Timeline Expectations

The installation of physical termite barriers is often quick but highly dependent on the stage of construction and coordination with other trades.

• Design & Specification: 1-3 weeks (integrated into overall architectural/engineering design process).
• Under-slab/Perimeter Embedded Barriers: 0.5 - 1 day for a typical home. This occurs after sub-grade prep and before slab reinforcement is fully tied/slab pour. Precise scheduling is critical with your concreter.
• Penetration Collars: Installed same day as under-slab barrier or just prior to slab pour. Requires careful coordination with plumbers/electricians.
• Granular Barriers: 1-2 days post-slab cure, before landscaping. Requires specific trenching and compaction.
• Certification: Issued within a few days of satisfactory installation and payment.

Timeline Note: Delays can occur if incorrect materials are delivered, if site preparation is inadequate for barrier installation, or due to poor coordination between trades (e.g., rebar installers, plumbers, termite barrier technicians). Plan for contingencies.

Common Mistakes to Avoid

Owner-builders, especially at an advanced level, need to be proactive in identifying and mitigating potential pitfalls. Termite management system failures often stem from preventable errors.

1. Bridging the Visual Inspection Zone: The most frequent error. This occurs when soil, mulch, paving, decking, or external cladding is installed above or against the 75mm exposed slab edge. This creates a concealed pathway, entirely negating the purpose of the visual zone. Owners often make this mistake post-Occupancy Certificate during landscaping.

   Solution: Strictly enforce the 75mm rule during landscaping. Use inert materials (e.g., gravel, pebbles) in garden beds immediately adjacent to the building. Ensure deck and patio bearers are isolated from the slab or built away from the perimeter.

2. Lack of Continuity at Slab Penetrations: Pipes, electrical conduits, and other services penetrating the slab are prime entry points. If these are not correctly wrapped or collared with a compliant barrier, the entire system is compromised.

   Solution: Mandate the use of approved pipe collars or specialty boot systems for every penetration. Ensure these are installed by the pest control technician, not just the plumber or electrician, as per AS 3660.1 requirements. Photographic evidence should be taken during installation before the pour.

3. Damage During Construction: Physical barriers, once installed, can be inadvertently damaged by other trades. A dropped tool, wheelbarrow run over an edge, or careless backfilling can tear membranes or displace granular barriers.

   Solution: Implement a strict site management plan. Clearly cordon off areas where barriers have been installed. Educate all subcontractors (especially concreters, roofers, and landscapers) about the importance of the termite barrier. Conduct site walks and inspections after each trade to identify and rectify any damage immediately.

4. Incorrect Backfilling and Drainage: Poor drainage around the slab edge leads to moisture accumulation, which attracts termites. Backfilling with organic matter (e.g., topsoil containing wood chips, roots) provides a food source right next to the building.

   Solution: Ensure proper site grading away from the slab (minimum 5% slope for 1m). Use only clean, non-organic fill materials (e.g., sand, crushed rock) adjacent to the foundation. Install effective subsurface drainage where necessary (e.g., ag-drains).

5. Ignoring Attachable Structures: Verandahs, patios, decks, carports, and garages are often seen as separate but are integral to the termite management strategy if attached to the main dwelling. Leaving these unprotected can allow termites to enter the main structure via the common wall.

   Solution: Treat attached structures as extensions of the main building's termite management perimeter. Install a continuous vertical barrier at the interface between the Class 1 and Class 10a slabs, extending to the FGL and tying into the main building's barrier system.

6. Failure to Maintain Annual Inspections: Physical barriers are highly effective but are not set-and-forget. Damage can occur, and termites can still explore. Annual inspections by a licensed professional are critical for early detection.

   Solution: Budget for and schedule annual inspections. View the Certificate of Termite Management not as a one-off document but as part of an ongoing maintenance cycle.

When to Seek Professional Help

While owner-building empowers you with significant control, certain aspects of termite management demand specialist expertise. Knowing when to engage professionals is a mark of a shrewd and responsible owner-builder.

1. Structural Engineer:

   • Foundation Design: For any non-standard slab edge details, complex articulation joints, or situations where the 75mm visual inspection zone cannot be maintained due to architectural design, an engineer's specification for the barrier system and its integration with the slab is critical.
   • Complex Sites: Sloping sites or sites with unusual soil conditions may require engineered solutions for sub-slab drainage and barrier integration.

2. Licensed Termite Management Specialist (Pest Controller):

   • System Selection and Installation: This is non-negotiable. Only a licensed professional can install approved physical barriers and issue the mandatory Certificate of Termite Management. They are experts in AS 3660.1 compliance.
   • Specific Product Warranties: Manufacturer warranties for most physical barrier systems are contingent on installation by certified applicators.
   • Annual Inspections: Beyond the initial installation, regular comprehensive termite inspections must be carried out by a licensed and experienced pest management technician (refer to AS 3660.2).

3. Building Certifier:

   • Design Phase Approval: Present your proposed termite management strategy, including detailed slab edge plans, to your certifier for pre-approval. They provide the ultimate verification of NCC and state-specific compliance.
   • Inspections: The building certifier will conduct mandatory inspections at various stages, including prior to slab pour, to verify compliance of termite barriers. They will require photographic evidence from your termite management specialist.

4. Landscaper (Experienced in Compliance):

   • Perimeter Detailing: If your landscaping design is critical for aesthetics, engage a landscaper familiar with building compliance. They can advise on materials and designs that respect the 75mm visual inspection zone or integrate with concealed barrier systems without compromising their integrity.

Crucial Reminder: Never attempt to install certified physical termite barriers yourself unless you are a licensed and certified applicator for that specific system. This contravenes regulations, voids warranties, and more importantly, leaves your home vulnerable.

Checklists and Resources

Pre-Construction / Design Phase Checklist

• Site Assessment: Confirm termite hazard level for your region (with certifier/pest consultant).
• System Selection: Research and choose a compliant physical termite barrier system (mesh, sheet, granular) suitable for your slab edge details.
• Engineer Consultation: Engage a structural engineer to incorporate barrier details into slab plans, especially for complex architectural designs.
• Pest Consultant Engagement: Obtain quotes from licensed termite management specialists; discuss system integration and warrantee.
• Certifier Approval: Submit detailed plans of the chosen termite management system (including slab edge details and product specifications) to your building certifier for pre-approval.
• Budget and Schedule: Allocate sufficient funds and time for barrier installation and coordination.

During Construction / Installation Phase Checklist

• Site Preparation: Ensure sub-grade is clear of organic matter (roots, timber) within 300mm of the building footprint.
• Formwork: Verify formwork is set to achieve a minimum 75mm exposed slab edge above FGL/paving, or as per engineered design for concealed barriers.
• Barrier Installation (Pre-Pour):
  • Confirm pest management specialist is on site at the correct time.
  • Verify under-slab barrier (if applicable) is correctly laid with overlaps sealed.
  • Check slab edge barrier material is correctly extended vertically and horizontally (if required) and securely fixed.
  • Confirm all service penetrations (pipes, conduits) have compliant termite collars/boots installed and sealed by the specialist.
  • Take comprehensive photographic evidence of the installation before concrete pour.
• Concrete Pour: Ensure concreters are aware of the installed barriers and avoid damage.
• Formwork Stripping: Carefully monitor formwork removal to prevent barrier damage.
• Granular Barrier (Post-Pour, if applicable): Ensure trench is correctly excavated, geotextile laid, and particulate barrier installed and compacted as per AS 3660.1.

Post-Construction / Handover Phase Checklist

• Visual Inspection Zone: Verify the minimum 75mm exposed slab edge is maintained around the entire perimeter.
• Landscaping Design: Ensure landscaping (soil, mulch, paving, decking) does not bridge the inspection zone or compromise concealed barriers.
• Termite Certificate: Obtain the mandatory Certificate of Termite Management from the licensed pest control operator.
• Annual Inspections: Schedule and budget for annual termite inspections by a licensed professional.
• Maintain Records: Keep all termite management system documentation (plans, certificates, warranties, inspection reports) with your building records.

Useful Resources and Contacts

• National Construction Code (NCC): Access via Australian Building Codes Board (ABCB) website (free registration required). Specific reference: NCC 2022 Volume Two, H1.D7.
• Australian Standards: Purchase AS 3660.1:2014 Termite management Part 1: New building work and AS 3660.2:2017 Termite management Part 2: In and around existing buildings and structures from Standards Australia.
• State Building Regulators:
  • NSW: NSW Fair Trading (www.fairtrading.nsw.gov.au)
  • QLD: Queensland Building and Construction Commission (QBCC) (www.qbcc.qld.gov.au)
  • VIC: Victorian Building Authority (VBA) (www.vba.vic.gov.au)
  • WA: Building Commission (www.dmirs.wa.gov.au/building-and-energy)
  • SA: Consumer and Business Services (CBS) (www.cbs.sa.gov.au)
  • TAS: Consumer, Building and Occupational Services (CBOS) (www.cbos.tas.gov.au)
• BlueScope Steel: For technical information on TRUECORE® steel framing (www.bluescopesteel.com.au).
• Work Health and Safety: Safe Work Australia (www.safeworkaustralia.gov.au) and your state-level WHS regulator.
• Industry Associations: Australian Environmental Pest Managers Association (AEPMA) provides a list of licensed and accredited pest management professionals.

Key Takeaways

For the advanced owner-builder constructing a steel frame kit home in Australia, mastering slab edge details for termite management is not just about compliance; it's about safeguarding your investment. The 75mm exposed concrete slab edge is the most fundamental and cost-effective visual inspection zone, mandated by NCC and AS 3660.1, preventing concealed termite entry by forcing them to build visible tunnels. When integrating physical termite barriers, precision, continuity, and professional installation are paramount.

Never compromise on a compliant system to save marginal costs. Understand that while TRUECORE® steel frames are termite-resistant, the non-timber components of your home remain vulnerable. Proactive design, rigorous site management, and diligent post-construction maintenance, particularly consistent annual inspections, form the bedrock of long-term termite protection. By meticulously addressing these advanced considerations, you ensure your self-built steel frame home stands as a resilient and protected asset for decades to come.