For centuries plants have been used as a thermal cushion to shield walls from intense solar heat or wind driven cold. Index offer a modular green wall system which comprises rails which are fixed to the building’s face leaving a 50-200mm zone between it and the follow-on cladding panels. This ventilated cavity ensures that rain does not penetrate through to the structure. It also allows insulation boards to be integrated into the system, where required, to provide an external Part L solution. Cassettes, nominally 600mm wide x 300mm high containing the growing medium and decorative plantings are then mechanically fixed in a modular series. Bespoke panels can be fabricated to suit any finishing dimensions, openings or even curves.
Selected growing medium in the suspended cassettes absorbs and maintains 80% of liquid by volume while still leaving approx. 15% of air pockets to ensure active growth. It is necessary in most cases to install an irrigation system to ensure the plantings receive measured levels of water and nutrients to each section of the wall to provide the perfect environment for them to thrive in. Because the plantings are grown in nursery conditions they can be delivered to site in their cassettes once major building wet trades have been completed. Being a modular system the living wall palette can be changed with the seasons, a highly important factor in tourist areas and public landscapes. These living walls are also an effective way of overcoming problems of graffiti.
Recent University research has found that there could be a 30% reduction in our streets’ pollution levels through the intelligent use of living walls. As well as turning carbon dioxide into oxygen through photosynthesis, plants clean the air by soaking up nitrogen dioxide and particulate matter.