What Cladding to Consider
External cladding protects a structure from the elements, enhances its aesthetic appeal and adds to structural integrity. The fire safety of structural cladding has also been under scrutiny in the last few years.
When choosing external cladding, Australian designers and contractors must consider its compliance with Australian Standards AS 5113 and AS 1530, which lay out combustibility standards for large and small-scale structures.
There are also the 2018 amendments to the NCC’s requirements for external cladding, which include a new verification method, CV3, for fire propagation qualities.
From metal to ceramics, timber to concrete, here are some options for external cladding that are safe, beautiful and practical.
Timber cladding
Wooden finishes continue to have the wow factor that architects desire. In an environment dominated by concrete, hardwood timber such as blackbutt or spotted gum, with its natural variation, can be treated against termites and the weather.
While timber cladding needs re-staining periodically, this is a small price to pay for the result; especially when timber is used on ground-level structures where natural subtleties have more impact.
Timber-look aluminium cladding
Given that external cladding with timber is problematic in tall buildings due to flammability and cost, timber-look aluminium cladding is the preferred alternative.
The use of timber-look aluminium as an architectural element gives an architect a powerful visual palette of parallel lines. This product also retains its finish without maintenance, with finishes resembling hardwood timber like iron bark, cedar and jarrah.
Aluminium cladding
Non-corrosive, attractive, light and strong, aluminium is a popular choice for external cladding. With contemporary aluminium products, many types of texture, moulding and finish are possible. Add to this very low maintenance and easy implementation, and aluminium cladding makes it near the top of the external cladding list.
It's important to note that aluminium cladding is different to aluminium composite cladding, which contains high-density polyethene, or HDPE.
It was this type of cladding that caused the devastation at London’s Grenfell Tower in 2017 and prompted revisions of Australian and international standards around combustibility (e.g. AS 1530.1).
Fibre cement cladding
Made from cement, sand and cellulose, fibre cement panels have an organic, stone look that suits a high-architectural style. Resistant to weather, fire, rot, termites and moisture, fibre cement is easy to build with and cuts cleanly.
The thickness of fibre cement products, also known as fibre reinforced cement (FRC), ranges from 4.5 - 18mm. These products require little maintenance once installed. The thicker/denser fibre cement products have excellent impact resistance, but thinner products need to be protected from impact.
Brick veneer cladding
Having the look of brick but playing no structural role, brick veneer is a popular finish on apartments, especially in areas where new developments must fit with existing brick residential or commercial buildings.
Fitted to a steel or concrete structure, brick veneer can be arranged in traditional or modern patterns, from herringbone to basketweave. The many textures and colours of brick can be used to add character to a design. Although not intrinsically waterproof or a good insulator, brick veneer can be back-filled with insulation and fitted with drainage channels to take water from the structural surface beneath.
These materials show that the choice of cladding is crucial to a building’s safety and its aesthetics. Smart, safe choices are made when both considerations are combined through the imagination of architects and skilful implementation by commercial contractors.