Green roofs are found on buildings that are either partially or completely covered by vegetation like grass, plants or even small trees. They are planted over a waterproofing membrane, often consisting of layers including drainage systems, irrigation systems and root barriers.
The purpose of a green roof is to not only provide insulation and a habitat for wildlife, but also to absorb rain water and mitigate the heat island effect. In Australia, you may have noticed that green roofs have been growing in popularity throughout the last decade. Let’s take a look at a few examples.
In 2010, The Victorian Desalination Project was announced, aiming to have almost 100,000 native plants across a green roof of more than 26,000 square metres. The idea behind this green roof is to blend into the landscape as part of the desalination plant’s sophisticated roofing system.
Earlier examples of green roofing in Australia include the Freshwater Place residential tower in Melbourne (2002); with its Level 10 rooftop called ‘Half Acre Garden’.
There’s also the CH2 building which houses the Melbourne City Council (2006), Australia’s first 6-star Green Star Design commercial office building as certified by the Green Building Council of Australia, and the Condor Tower with a 75-square-metre lawn on the 4th floor.
As you can imagine, green roofs with such complexity like those mentioned above require specialised green roof drainage systems. Drainage can be tricky, especially during times of storming when there is an excess of water.
Let’s take a look at one type of specialised green roof drainage system – ACO ProfiLine.
Excess water can be difficult to manage – and this is why ACO ProfiLine has been designed for green roofs to provide protection for buildings – collecting water as it runs down the facade, as well as below the drain’s surface through perforations in the channel walls.
The ProfiLine system can be installed directly above the roof or balcony membrane. The concept for the system has been carefully thought-out, so much that it has the ability to drain water from pavement surfaces, or by means of a grate along the facade.
The features of the ProfiLine design concept include:
- Height adjustable channels
- Choice of grates
- Stainless or galvanised steel construction; and,
- Perforated side walls (allowing for inward and outward percolation of rainwater)
In addition to green roofs, the ProfiLine can be applied to:
- Flat roofs
- Vertical facades; and,
Throughout periods of heavy storming, the ProfiLine system acts as a surface water trench drain. This is important because when the soil has been saturated during heavy rain fall, water can only be collected via the grate. This is in contrast to lighter rain fall, when water will seep through channel walls, enabling ProfiLine to function as a subsurface trench drainage system instead.
As a result of the above, ProfiLine is ideal for any type of situation, regardless of how heavy the rain fall is. However, as a general rule, it should be ensured that water is always directed towards the area it is required – this way it can be managed more effectively.