Designing cantilevered terraced houses is simplified with KOROK® fire and acoustic wall systems. Whether you need cantilevered eaves or cantilevered walls, KOROK has detailed solutions to suit your needs.

Our systems help you create functional and stylish designs, such as:

• Maximizing floor space with larger second-story extensions.

KOROK’s innovative cantilevered wall systems are engineered to provide superior performance, offering both structural stability and efficient installation for terraced house construction. Choose KOROK® to streamline your building process and meet the demands of modern architectural design.

For Terraced Housing

Cantilevered terraced house design is easy with KOROK®. We have details for both cantilevered eaves and cantilevered walls. So if you’re wanting your buyers to be sheltered from the weather with an inset front door; or if you’re wanting to maximise your floor space with a larger second storey, we have the product to make that happen.

Cantilevered Eaves

Cantilevered Walls

For External Applications – (Commercial Only)

A Typical Parapet Detail illustrates the structure and support of a parapet wall, commonly cantilevered from the main building structure. This detail focuses on connections that ensure stability and durability, including reinforcement and weatherproofing layers to protect against the elements. Cantilevered parapets require careful attention to load distribution and deflection control, as they extend outward without external bracing, creating a clean, streamlined edge on the building façade.

Typical parapet detail

Typical parapet detail

High Performing and Lightweight

KOROK® 78mm galv panels are precision rollformed from high-quality zinc-coated steel strips. The steel used for our shells meets the AS/NZS1397:2001 standard, ensuring consistent strength and durability. Each panel features a base metal thickness of 0.4 mm B.M.T. with a Z275 zinc coating, enclosing a lightweight aerated concrete core. This combination delivers a nominal weight of just 10.2 kg per lineal metre, making KOROK® panels easy to handle and install while maintaining exceptional structural performance.

Our panels are designed for versatility and high performance, offering superior fire and acoustic ratings for a wide range of applications. They provide fast, efficient installation with minimal on-site modifications, reducing labour costs and program delays. The lightweight nature of KOROK® panels also eases transport and handling, particularly on multi-storey construction projects.

Backed by over 20 years of experience, KOROK® panels are BRANZ-appraised, Kiwi-owned, and widely trusted across New Zealand for projects ranging from residential developments to complex commercial constructions. Our systems are designed to simplify installation, maximise safety, and deliver long-lasting performance, making KOROK® the preferred choice for builders, architects, and developers seeking reliable fire and acoustic wall solutions.

High-Performing and Lightweight Panels for Superior Building Solutions

Engineered Fire and Acoustic Systems for Industrial and Commercial Spaces

KOROK® Warehouse and Retail Systems are high-performance, non-loadbearing internal wall systems designed to provide secure fire separation and acoustic control in industrial, warehouse, bulk retail, and intertenancy environments.

The system consists of interlocking steel-faced panels with an aerated concrete core, engineered for certified fire resistance, acoustic attenuation, structural reliability, and long-term durability. Panels can be installed vertically or horizontally and are suitable for both single-wall and twin-wall configurations. The systems have been developed in accordance with recognised Australian and New Zealand Standards and are substantiated through BRANZ testing and appraisal (Appraisal No. 559), ensuring verified and compliant performance.

How the System Works

KOROK® panels are roll-formed from zinc-coated steel strips and encapsulate a lightweight aerated concrete core. The interlocking tongue-and-groove profile forms a continuous sealed barrier that enhances both fire integrity and acoustic isolation.

System performance is achieved through the combined effect of panel mass and composite action, the engineered interlocking joint design, and a tested fastening and support methodology. Optional linings and cavity configurations can also be incorporated to meet specific Fire Resistance Rating (FRR) and Sound Transmission Class (STC) requirements.

Systems are non-loadbearing and must be supported by primary structural elements designed in accordance with NZBC structural requirements. Only genuine, tested KOROK® panels and proprietary components guarantee certified system performance. Substituting alternative products may compromise fire and acoustic ratings and cannot be supported or certified.

KOROK Warehouse and Retail Systems

All-in-One Fire & Acoustic Solutions for Boundary and External Walls

KOROK® External Wall Systems are non-loadbearing, fire- and acoustically-rated vertical wall systems combining a zinc-coated steel outer shell with a 400kg/m³ aerated concrete core. BRANZ appraised and designed for New Zealand conditions, they provide durable, high-performance external and boundary wall solutions for commercial and industrial buildings.

Delivering fire rating, acoustic separation, and weather-tight performance in a single integrated assembly, the lightweight system enables faster installation, reduces structural demand, and can eliminate the need for specially engineered slabs on many projects. Available in single-skin or over-clad configurations, the systems are engineered to perform under defined design wind pressures.

How the System Works

The system uses 78mm interlocking panels with a 250mm effective cover width, installed vertically to form a continuous fire- and acoustically-rated barrier. The interlocking geometry limits acoustic leakage while maintaining fire-resisting continuity. The steel shell provides durability and weather protection, and the concrete core delivers inherent fire resistance and acoustic mass. Five system configurations are available:

• EX1 – 78mm COLORSTEEL® panel, single-skin system
• EX2 – 78mm COLORSTEEL® panel with internal fire-rated lining
• EX3 – 78mm panel with engineered over-clad metal system
• EX4 / EX5 – Over-clad systems incorporating internal fire-rated lining

All systems provide two-way fire resistance and are designed as vertical in-fill wall systems fixed to supporting primary structures.

External Wall System Engineered for Commercial and Industrial Applications

KOROK® External Wall Systems are suitable for warehouses, factories, sheds, cinemas, lift shafts, and other commercial applications where fire separation and acoustic control are critical.

EX1 and EX2 systems are appraised as single-skin, non-loadbearing, fire- and acoustically-rated external walls. EX3, EX4 and EX5 systems incorporate drained and vented cavity cladding systems and are subject to project-specific engineering design. The systems are designed for defined wind pressures and vertical span limits, ensuring controlled structural behaviour under service and ultimate limit state conditions.

COLORSTEEL® Options:

Choose from a full range of COLORSTEEL® options to match your project’s external design. Explore our CAD Library for DWG files related to KOROK® External Wall Systems. Access detailed KOROK® External Systems Literature for specifications, installation guides, and more. If you have any questions or need further assistance, contact us for more information.

Durability and Service Life

Service life performance depends on environmental exposure category. COLORSTEEL® MAXAM™ external shells provide up to 25 years resistance to perforation in defined NZS 3604 zones, with paint finish durability of 15 years under normal conditions. Panels are intended to remain rain-washed and fully exposed. Geothermal environments require consultation with the relevant Building Consent Authority.

KOROK® External Wall Systems