An important component of a green façade installation is the selection of the most appropriate support structure to suit the design and the building. Though climbers are known to cling directly to a wall surface, a support structure is required for a green façade on a multi-storeyed building to withstand wind and movement pressures.
Tensile recommends the use of metal structures for the purpose as opposed to wooden or plastic alternatives, for reasons such as longevity, strength, wind resistance and easier maintenance. Prior to designing a green façade and selecting the right support structure, it’s important to ascertain that the building can indeed withstand the weight and forces of a complete green façade structure. While this can be done at the design stage in a new building, retrofit applications will need a thorough assessment of the building to find the best solution for the particular site.
Considerations include the weight of dead loads (such as the final weight of the structure and all components), and transient loads such as wind and movement.
Metal structures
Green façade structures in metal include stainless steel netting, steel and wire rope systems, and cabling and hybrid systems. However, regardless of the chosen structure, precision engineering is required for optimum results.
For instance, cables need to be pre-tensioned to 1-2 kiloNewton or kN (with 1 kN equating to a load of approximately 100kg), and dead weight of plantings at 8kg per square metre. The engineering also needs to allow for 80% porosity as plantings tend to let a lot of wind through. The mesh should allow for 20kg weight per lineal metre while loads for hybrid systems are the same as for cables, plus the weight of the planter units at 60-80kg/m².
Common pitfalls
Over-engineering a façade structure will only add to the cost, which is unnecessary since some cabling systems are engineered way beyond the climbing plant requirements of 8kg per square metre, going even as high as 60kg. Precision engineering, as opposed to estimating or guessing, helps to avoid the extra expense that over-engineering can create.
Case Study: Warringah Mall Brookvale NSW
An example of Tensile’s know-how, experience and precision engineering is the Warringah Mall project in Brookvale NSW, which features a hybrid façade of planter units, and columns up to 14 metres in height. The green façade is suspended from cables rated to take up to 400kg, and the entire system is wrapped in Webnet mesh, applying 20kg per pre-tension. The system was engineered for 14-18 plant units per column, which eventually will become covered in greenery.
Precision solutions with Tensile
The Tensile team carries out an accurate and precise assessment of projects to arrive at the best solution for a green façade support structure. Tensile can design and engineer the green façade structure, or collaborate with a consultant team to meet the client’s objectives.
