According to the Guardian recently, Mexico City is trying to do something about its pollution problem by installing a number of azoteas verdes or green roofs. Hospitals, schools and offices have been the subject of a $1 million experiment to create a greener and healthier environment.
And Mexico is not the only city that is trying to go back to nature. New York has been a fan of green roofs for a while now. They are thought to have several effects apart from the aesthetic, including soaking up around 70% of the rainfall – great for a city that has long suffered from flooding due to run off water. A Columbia researcher has found that if all of New York’s roofs were turned green it would stop 10 billion gallons of water from entering the city’s sewer system.
With 944 million square feet of roofing, there’s plenty of opportunity in New York for a roof garden. It’s becoming a bug too with prices coming down and roofing businesses incorporating it into their product offers.
Green roofs aren’t a new thing. The Germans have been making them since the 1940s, as have the Norwegians. The truth is that green roofs have been around for centuries in one way or another. They have a number of benefits including insulation, reducing greenhouse gasses and purifying water, as well as having a certain visual appeal and providing additional habitat for the much lamented bee and other insects and animals.
Many people think that green roofs are high maintenance, that they cause structural problems to the building underneath and even leakage. Most well designed roof gardens should have a protective layer to stop roots breaking through and it is a myth that they cause more damage and are high maintenance. There’s even a suggestion that a green roof might protect you from damage and some experts say they can double the lifespan of a normal roof.
There could also be considerable energy saving benefits of having a green roof. Having an extra layer of insulation on your roof can decrease the amount of heat lost in winter and keep down energy bills as well as providing a cooler environment in the depth of summer.
Building a Green Roof
It’s not simply a case of throwing some soil on your roof and planting a bunch of nice azaleas. A garden roof will probably need a good deal of thought and access to some expertise. You need to be sure, first and foremost, that your roof can take the additional weight and that it is otherwise suitable for such a construction. You will also need a weather proof membrane, a root protection layer and a drainage layer before you even get round to your growing medium.
While you may have the technological and building know how to build your own roof, most of us will need to hire someone who knows what they are doing.
There’s no doubt that green roofs are becoming more and more popular across the world as we try to find new and innovative ways of making our world a nicer an eco-friendly place to live. Expect to see brighter and lusher city centres as people turn their spaces into something more aesthetically pleasing than tar and tiles.