The latest round of high-rise fire disasters involving sub-par cladding materials serve to highlight the potential sustainability and efficiency advantages brought by better quality systems for covering building exteriors.
While traditionally considered to be a cut-and-dry construction material whose sole purpose is to provide protection against the rigours of harsh weather, cladding can also serve a highly effective means of improving the sustainability and efficiency of buildings themselves.
This ability of cladding to play a greater role in enhancing the building envelope is perhaps highlighted by the recent safety failings of exterior wall installations in Australia and other parts of the world. Sub-par cladding has actually contributed to fire disasters in both Melbourne and Dubai in recent times, while it was recently revealed that Victoria’s tallest building is decked out in flammable product.
The dilemma of sub-par cladding would appear to be more widespread that previously anticipated, with a recent audit by the Victorian Building Authority uncovering a slew of non-compliant buildings in the heart of downtown Melbourne.
Instead of turning to sub-par material to cut down on short-term overhead, designers and developers could instead be availing themselves of higher quality cladding systems to shore up the safety, sustainability as well as aesthetic appeal of their building exteriors.
Some of the higher quality exterior insulation and finish systems (EIFS) serve as perhaps the best examples of cladding options currently available on the market which can serve to improve building performance across a broad range of areas.
EIFS are non-load bearing building cladding systems made from integrated composite materials. They generally consist of insulation boards made using materials such as expanded polystyrene, adhesive or mechanical fasteners that attach these boards to a substrate, as well as a reinforcing mesh to shore up resistance to fire or external impact.
Base coats are added to improve weather resistance and further secure the reinforcing mesh, while a finishing coat can be used to raise durability as well as impart aesthetically pleasing design qualities.
EIFS have been employed in North America since the 1960s, becoming a particularly sound option for wood-framed buildings toward the end of last century. Historic issues with water infiltration have led manufacturers to include drainage planes in the products, permitting the discharge of water to the rear of the cladding during heavy rainfall.
EIFS possess particularly strong insulating properties that can improve the efficiency performance of buildings.
The continuous insulation (CI) which is an intrinsic part of these cladding systems serves to reduce air leakages and eliminate thermal bridging almost completely, dramatically reducing heat flow between building interiors and the outside environment.
The continuous insulation provided by EIFS as a system external to the building structure stands in stark contrast to traditional insulation that is installed within wall cavities, the effectiveness of which can be significantly comrpomised by thermal bridging.
The enhanced insulating ability of EIFS can dramatically improve building efficiency when it comes to both the heating and cooling of interiors, thus reducing the burden on the HVAC systems which comprise a primary source of energy consumption by built environments.
The ability of EIFS to improve the energy efficiency of buildings has long been known by the North American construction sector, which was on the verge of making the cladding system a mainstay product in the wake of the 1970s oil crisis that left consumers with increasingly hefty energy bills.
In addition to the elimination of thermal bridging, EIFS can serve to improve the efficiency of the building envelope when it comes to mitigating other forms of interaction with the surrounding climate or outside environment.
EIFS can control the flow of water vapour, thus preventing problems caused by the accumulation of condensation within building interiors.
Moisture reduction is particularly important for building durability and long-term performance, given the damage that mould proliferation can cause following the buildup of condensation. The moisture prevention capabilities of EIFS can be improved via the addition of vapour control layers where required, while condensation potential is further reduced via isolation of the insulation from the stud-cavity wall construction.
The superior insulating properties of EIFS can also improve acoustic control and help cut down on noise pollution, thus improving the comfort of building interiors for occupants.