The move to ‘green’ the planet via rooftop gardening, to convert ugly concrete jungles into sustainable, usable green living areas, is increasing. Roof top gardens offer significant health, environmental and societal benefits. So why isn’t everybody doing it immediately? Well, it’s not without its challenges.
Two major challenges facing rooftop garden design is managing the weight restrictions and drainage issues. Solving these problems is Atlantis who have developed drainage cells of high strength, that are lightweight, easy to install, and compared to traditional methods, also low in cost.
These drainage cells were specifically developed to facilitate adding roof top gardens and planter boxes to building construction without having to add heavy aggregate for drainage. These cells drain excess water while retaining an optimum moisture level, which is ideal for promoting plant growth in planter boxes and roof garden applications.
An added bonus for the environmentally conscious is that Atlantis drainage cells are manufactured from quality recycled materials. They offer long term durability and are resistant to chemicals. Used in conjunction with Atlantis geotextile, it functions as a protective membrane for waterproofing and providing ventilation for concrete slabs which alleviates heat induced stress and cracking. It’s ideal for creating landscape mounts, structural fill for planter boxes, podiums and roof top gardens.
Problems solved! The next question is: Is it worth the bother? Here are a few reasons why rooftop gardens are worth the effort.
Enhancing Air Quality
Rooftop gardens enhance air quality. Rooftop gardens take carbon dioxide (CO2) out of the air while releasing oxygen. They absorb and transform sunlight and regulate ambient temperatures.
Rooftop gardens also lower both the surface and surrounding air temperatures through a process called evapotranspiration. This process reduces ‘heat islands’ in city communities responsible for increasing power demands and which also contributes to air pollution and greenhouse gases. In fact, rooftop gardens are proven to absorb heat and insulate buildings better than traditional roofing.
Reduce Energy Costs
Rooftop gardens are proven to assist in the reduction of energy costs because less power is needed for temperature control. Air conditioners don’t have to work harder or longer and there are fewer spikes in energy demands which also means reduced energy bills for consumers. (The National Research Council of Canada did a study and found exposed roofs can heat up to as much as 70 degrees Celsius on warm days whereas the same roof type, protected by a roof garden, remains around 25 degrees Celsius.)
Rooftop gardens also create large catchment areas for capture and harvest of rainwater. Rooftop trees and vegetation reduce stormwater runoff and protect against erosion. Canadian researchers found that roof gardens reduced the amount of runoff by as much as 75%, and delayed the run-off time by 45 minutes. In addition, run-off from bare roofs contain many pollutants, but this is also reduced as it is filtered through roof top garden soil.
Rooftop gardening also offers the opportunity to utilise these otherwise wasted building spaces to provide an affordable method to feed local populations. In Northern America, some restaurants are growing their ingredients on their own roof space. One company has established rooftop greenhouse farms and sells their produce in local city markets – a brilliant idea offering fresh produce without the need for expensive freight and providing employment for locals.
Enhancing Community Life
In other parts of the world, people living in apartment buildings have converted their wasted roof and landing spaces into communal garden areas where they can plant and share herbs and vegetables among residents. The health and cost savings for these families can be enormous.
Another benefit to rooftop ‘farming’ is the plants do not suffer from pest attacks like their ground-dwelling counterparts. Snails and slugs are too lazy to slime their way up skyscrapers!
And then there is the obvious benefit of adding aesthetically pleasing improvements to otherwise ugly concrete cityscapes. This also provides therapeutic benefits for those who live and work in high-rise buildings and offers space for relaxation or recreation that otherwise would not exist.
Finally, there are the savings from less wear and tear of roof structures during summer and winter months with contraction and expansion. Roofs covered by vegetation enjoy longer lifespans because contraction and expansion are reduced.
Initially, when considering a rooftop garden, you will need to contact your local Council for their laws and guidelines. Then you will need to determine what type of rooftop garden you want that meet the regulations. The easiest gardens involve container plants. These can include vegetables suitable for growing in pots and planter boxes. Just remember your rooftop garden will get very hot in summer, so choose plants that are more able to handle the added heat. Also, choose plants with non-invasive root systems or limited root systems that don’t need a lot of soil.
Obviously, you will also need to ensure your roof structure is suitable for a rooftop garden so you should consult a professional, an engineer or architect to determine this.
For some inspiring rooftop garden ideas, talk to the team at NewTechWood. Whether you want stylish, eco-friendly screening or decking, we’ve got the products to help make your rooftop garden an oasis.