Metal Roofing Options in Australia: Beyond Traditional Corrugated Roofing

When Australians think about a metal roof, COLORBOND® steel and ZINCALUME® steel are usually the first products that come to mind. They are widely used across Australian homes, sheds, verandahs, commercial buildings and industrial structures.

However, there is a much wider range of metal roofing available in Australia than the familiar corrugated sheet.

Profiles such as TRIMDEK®, SPANDEK®, KLIP-LOK®, LONGLINE 305®, Speed Deck Ultra®, Monoclad® and KingKlip® provide different appearances, fixing methods, spanning capabilities and applications. There are also specialist metal roofing materials, including aluminium and stainless steel, which can be considered where the environment or architectural requirements call for something different.

One important distinction should be made at the outset: COLORBOND® and ZINCALUME® describe steel materials and finishes, while TRIMDEK®, SPANDEK® and KLIP-LOK® describe roofing profiles or systems. A TRIMDEK® roof, for example, can still be manufactured from COLORBOND® steel or ZINCALUME® steel.

Understanding this difference makes it much easier for an Australian homeowner to compare the available metal roofing options.

TRIMDEK® Roofing

TRIMDEK® is one of the better-known alternatives to traditional corrugated roofing.

It has a trapezoidal ribbed appearance, with broad pans between the ribs. Compared with traditional corrugated roofing, it produces a more contemporary and structured appearance.

LYSAGHT® describes TRIMDEK® as a versatile roof and wall cladding profile suitable for residential, commercial and industrial buildings. The standard profile has a nominal cover width of 762 mm and a minimum roof slope of 2°, subject to the applicable design requirements.

The broad pans and relatively deep ribs give TRIMDEK® useful spanning characteristics, which can be advantageous when designing a roof with wider support spacing.

For Australian residential work, TRIMDEK® can be particularly suitable for:

• Modern homes
• Skillion roofs
• Verandahs
• Extensions
• Garages and carports
• Commercial buildings
• Low-pitched roof sections

The profile is generally installed with exposed fasteners, unlike concealed-fix roofing systems such as KLIP-LOK®.

SPANDEK® Roofing

SPANDEK® provides another distinctly different appearance.

Rather than the rounded waves of traditional corrugated roofing, SPANDEK® has a square-corrugated profile. This produces a stronger, more contemporary architectural appearance while retaining the familiar concept of profiled metal sheet roofing.

The LYSAGHT® residential roofing range describes SPANDEK® as a contemporary square-corrugated profile designed where a stronger and bolder corrugated appearance is required. Its profile combines strength, rigidity and relatively lightweight construction.

SPANDEK® can be used for both roofing and wall cladding, making it useful where an architect or homeowner wants the roof and wall materials to have a consistent appearance.

It is available Australia-wide through the LYSAGHT® range, although the exact product, material and finish available can depend upon the location and supplier.

KLIP-LOK® Concealed-Fix Roofing

KLIP-LOK® is particularly important when discussing alternatives to conventional screw-fixed metal roofing.

Instead of screws passing through the visible face of every sheet, KLIP-LOK® uses clips to secure the roofing sheets. The fixing system is therefore largely concealed beneath the roofing sheets.

This gives the finished roof a clean appearance with long uninterrupted lines and fewer visible fasteners.

LYSAGHT® currently offers KLIP-LOK® profiles including KLIP-LOK® 406, KLIP-LOK 700 CLASSIC® and KLIP-LOK 700 HI-STRENGTH®. Some versions are designed for roof slopes as low as 1°, subject to the relevant product and design requirements.

The concealed fixing arrangement can also be particularly useful on low-pitched roofs because there are fewer exposed penetrations through the roof sheet.

KLIP-LOK® is used on Australian residential, commercial and industrial buildings and is particularly suited to modern architectural designs.

LONGLINE 305®

LONGLINE 305® is another profile designed around a modern architectural appearance.

It uses tall, slender ribs separated by relatively broad, flat pans. The result is quite different from both corrugated roofing and the heavier appearance of some trapezoidal profiles.

It can be used for both roofing and walling and is particularly suited to buildings where long, clean lines are an important part of the design.

LYSAGHT® also lists a Western Australian variant of LONGLINE 305®, which is worth noting when researching roofing options for homes and buildings in WA.

Standing-Seam and Architectural Metal Roofing

There is also a growing range of standing-seam and architectural metal roofing systems available in Australia.

These systems are designed to produce a relatively clean roof surface with concealed or specialised fixing arrangements. Rather than relying on the familiar corrugated or trapezoidal appearance, they can produce long, narrow lines across the roof.

Examples in the LYSAGHT® architectural range include:

• ENSEAM®
• SNAPSEAM™
• IMPERIAL™
• LONGLINE 305®

LYSAGHT® describes IMPERIAL™ as a high-performance standing-seam steel roofing and walling profile capable of being curved. ENSEAM® uses a nailstrip-style arrangement, while SNAPSEAM™ uses a clip-fixed nailstrip system.

These products are more likely to appear on architect-designed homes and commercial buildings where the appearance of the roof is an important part of the overall building design.

Stramit Speed Deck Ultra®

Another significant Australian roofing option is Stramit Speed Deck Ultra®.

This is a concealed-fixed decking profile designed for long-run roofing. Stramit states that the product has a wide cover, deep ribs and full-length clips, with roof pitches as low as 1° possible subject to the applicable requirements.

The concealed fixing arrangement means the roof does not have the rows of exposed screw heads normally associated with conventional screw-fixed roofing.

Speed Deck Ultra® is used on commercial and industrial buildings but can also be used on domestic buildings. Its large water-carrying capacity and low-pitch capability can make it useful where conventional roofing profiles are unsuitable.

Interestingly, Stramit states that Speed Deck Ultra® can be manufactured from hi-tensile steel as well as aluminium-zinc-magnesium alloy or zinc-aluminium alloy coated steel.

This illustrates why simply describing a roof as a “metal roof” does not provide enough information about the actual roofing material.

Stramit Monoclad® and Longspan®

Stramit also manufactures several other Australian roofing profiles that move beyond conventional corrugated roofing.

Monoclad® is a long-run roof and wall cladding profile designed around water-carrying capacity, wind-load performance and relatively straightforward fixing.

Longspan® provides another long-run option with prominent linear ribs.

Stramit lists both products among its roofing options suitable for applications including residential buildings, commercial buildings and low-pitch roofs.

These profiles demonstrate that there are many different forms of screw-fixed and concealed-fixed steel roofing available to Australian builders and homeowners.

Fielders® KingKlip® 700

Another Australian option worth knowing about is Fielders® KingKlip® 700.

KingKlip® 700 is a concealed-fix roofing system with a 700 mm cover width. Fielders’ current technical information lists it as available in NSW, Victoria, South Australia and Western Australia, with different design capacities depending upon the base metal thickness and application.

For homeowners in Western Australia, this is particularly relevant because it demonstrates that KLIP-LOK-style concealed-fix roofing is not limited to a single manufacturer.

Fielders also offers other profiles, including TL-5®, Spanform™ and C-Dek™ 310, providing further alternatives to conventional corrugated roofing.

Aluminium Roofing

Steel is not the only metal that can be used for roofing in Australia.

Aluminium roofing can be particularly useful in locations where corrosion resistance and low weight are important considerations.

LYSAGHT® offers PERMALITE® aluminium roofing for marine and other challenging environments. Its range includes WAVELINE®, which provides a traditional Australian corrugated appearance, and ALSPAN®, which has bold ribs and broad pans.

Aluminium has the advantage of being naturally resistant to corrosion and is significantly lighter than many steel roofing products.

This can make it an option worth investigating for some coastal and marine environments.

However, aluminium roofing is not automatically the right choice for every coastal property. Roof design, fixing systems, wind exposure, compatibility with other metals and the particular marine environment all need to be considered.

Stainless Steel Roofing

Stainless steel is another specialist metal roofing material available in Australia.

It is generally associated with situations where a higher level of corrosion resistance is required. Fielders’ current NCC compliance information, for example, identifies SUPERDURA® Stainless steel within its roofing material range and specifies it for very high corrosive environments.

Stainless steel is more specialised and is not normally the first choice for an ordinary suburban roof. However, it can become relevant for buildings in particularly aggressive environments.

The cost of stainless steel can also be considerably higher than conventional coated steel roofing, making the application and expected service conditions important considerations.

Copper Roofing

Copper is another metal that can be used for roofing, although it is a specialist material rather than a mainstream Australian residential roofing choice.

Copper develops a characteristic patina as it weathers and can provide a distinctive architectural appearance.

Australian roofing documentation from Stramit includes copper among the materials available for certain applications, including its Speed Deck® 500 system, although availability and suitability depend on the particular product and location.

Copper should also be considered carefully where it comes into contact with, or drains onto, other metals because galvanic corrosion can occur.

Choosing the Right Metal Roof Profile

The most suitable metal roofing system is not necessarily determined by appearance alone.

Australian roof design needs to consider factors such as:

• Roof pitch
• Roof shape
• Wind classification
• Cyclonic requirements where applicable
• Sheet length
• Support spacing
• Drainage capacity
• Coastal exposure
• Corrosion environment
• Thermal movement
• Roof penetrations
• Flashings and cappings
• Fixing method
• Access for future maintenance
• Compatibility with other building materials
• Applicable Australian Standards and the National Construction Code

For example, a profile capable of operating at a very low roof pitch can be valuable on a skillion roof but may offer little advantage on a conventional steeply pitched tiled-roof replacement.

Likewise, concealed fixing can produce an attractive appearance and reduce exposed penetrations, but the complete roofing system—including clips, flashings, laps and installation details—must be correctly designed and installed.

Metal Roofing Is More Than Just Corrugated Sheet

The Australian metal roofing market provides homeowners with considerably more choice than the traditional corrugated roof.

TRIMDEK®, SPANDEK®, KLIP-LOK®, LONGLINE 305®, Speed Deck Ultra®, Monoclad®, Longspan®, KingKlip® 700 and architectural standing-seam systems can all provide very different appearances and performance characteristics.

There are also material choices beyond conventional coated steel, including aluminium and stainless steel, with copper available for more specialised applications.

The important point is that roofing profile and roofing material are two different things. A profile such as TRIMDEK® or KLIP-LOK® can be manufactured from particular steel products or finishes, while the underlying material and coating determine important characteristics such as corrosion resistance and durability.

For an Australian homeowner replacing an old roof, the decision should therefore begin with the building, roof pitch, environment and required performance rather than simply choosing a colour or sheet profile.

A properly selected metal roofing system can provide a long-lasting roof while also giving a modern Australian home a very different appearance from traditional corrugated roofing.

Product availability, profile dimensions, minimum roof pitches and suitable materials vary between manufacturers, products and Australian locations. Roofing should be designed and installed in accordance with the applicable manufacturer requirements, Australian Standards, the National Construction Code and relevant local requirements.