These days, some of the most modern construction projects utilising the latest, high-tech materials, are also using a centuries old method in the design of their roofs.
Living roofs, sometimes referred to as green roofs, were used as far back as the 11th century, in traditional Viking dwellings. These days, the feature can be found in the most innovative building projects, including Manhattan’s most famous landmark, the Empire State Building.
The benefits of the technique are numerous. A study conducted by the University of Toronto was the first of its kind to suggest that green roofs dramatically reduce the energy it takes to keep a building warm during winter. You can find more details from this study, here. The vegetation on the roof acts as a layer of insulation, locking valuable heat in during the winter and keeping it out during the summer. It’s become an attractive prospect in a building industry concerned with reducing its carbon footprint. They’re also more appropriate for building projects in rural locations which are required to blend in with the natural landscape.
However, what is perhaps the most attractive aspect of green roofs, can be identified when they are compared with more traditional tiled or felt roofs. These alternatives are susceptible to damage from water: a risk which is eliminated when vegetation on the roof relies on a water supply to stay alive.
Though the benefits are abundant, this isn’t a simple addition that any home can benefit from. Naturally, soil and vegetation are heavier than traditional roofing materials, even more so when wet; so not all existing constructions will be able to withstand the added weight. Before you install a green roof, you should consult a qualified surveyor who has assessed whether the building can bear the weight.
If your building is strong enough to cope with this extra weight, you’ll need to prepare the existing roof. Firstly, it will need to be completely waterproof; the most effective method of doing this is liquid waterproofing, which is suitable for both new and existing buildings. Take a look at Tor Coatings, a UK based company specialising in roof coating systems. This method will create a waterproof layer on the roof that will last for up to 25 years, although the protection offered by vegetation could extend this dramatically.
You’ll also need to install a filter sheet, otherwise the whole thing will slide off the roof when it rains. After that, you’re ready to begin planting. It’s possible to grow everything yourself, but this will increase the time it takes to create the roof and you’ll be waiting even longer to see the benefits. For a much faster option, companies such as Lindum supply turf and wildflower meadow mats that are suitable for use on a green roof project. Take a look at their selection of green roof products, which includes biodiverse mats and sedum. They also provide a lot of information and guidance for designing a green roof, complete with case studies and examples.
It’s somewhat strange, that in an industry which is constantly looking forward to new techniques, a building method created over 1000 years ago leads the way in modern construction.