Ultralight extensive green roof

Recently our perception of city has changed. It is not wise, practical or ethic anymore to think about urban areas as the contrast of nature. People started to look for ideas and solutions how to bring nature closer, how to make the environment more pleasant and habitable and not only for humans.

That is how green roof systems started to spread very quickly. These living roofs became natural biological systems and the negative urban spaces were transformed into beautiful green islands.

There are millions of sqm of conventional roofs all over the world, which could be given back to the nature by existing technical solutions. Once the way of thinking has been changed, we can find easy and cheap solutions to make our environment healthier and more comfortable. Using materials from our region during building or modernization works, we can save significant amounts of money.

Lots of people think that an extensive green roof needs great surfaces with very special characteristics. The truth is that for every type of rooftop garden it exists a landscaping method, regardless the material of the roof. As a first step we have to determine the carrying capacity and the inclination of the roof.
The main issue is the waterproofing of the roof, which has to be repaired before landscaping, otherwise subsequent interventions are quite costly and difficult. Thanks to these new solutions, landscaping can be performed on existent buildings too, without modifying or strengthening the building’s structure. Pitched roofs up to 60° can be also landscaped.

Extensive green roofs don’t need special care, because the mature vegetation is self-sustaining. The access on these surfacing is quite difficult because of the lightweight structure, so in the early design stage access roads for maintenance must be taken into account.

There are several landscape technologies for these ultra-light extensive green roofs, but all of them have the same purpose: minimizing weight on the surface. The vegetation layer when is water saturated, should not exceed 70 – 80 kg/m², but apart from that necessary conditions for plants must be ensured. In these gardens, vegetation is not too rich indeed; still we can find different type of succulents, like sedum or moss.

If we use porous materials for the compound method, it is very important for the drainage course to be able to retain the necessary amount of moisture and to ensure the evacuation of excess rainwater. Porous materials could be minerals or recycled, like expanded perlite, volcanic clay etc. Every centimetre of the layer’s thickness is actually the weight of the mineral substrate between 10-13 kg/m², in water saturated status.

We can use another technology too: replacing substrate with a layer of mineral wool. This material is optimized for water retention. Because of the low weight without volume, we can fix the mineral wool with ballast for example, until the full vegetation is rooted, which will stabilize later the ultra-light extensive green roof’s layers.

Regardless the methods used, a living green garden on the top of our roof can bring us satisfaction and multiple benefits. Change your grey and dusty urban roofs into beautiful rooftop gardens!

Our company offers consultancy and turnkey projects for green roof and terrace design, landscape and long-term maintenance in order to obtain the best results. There are special solutions to build green roofs, even in lightweight surfaces, regardless the materials used for the roof.

We work with reliable building materials, plants especially developed for rooftop gardens and high quality vegetation rolls. Every landscape work of ours offers the best cost/effectiveness/safety balance and every project is adapted to our customers’ aims.

We are able to landscape extensive green roofs on top of industrial halls, vertical gardens in office buildings, and intensive green gardens with special relaxing zones, landscape green roofs with pedestrian traffic for shopping malls and many other ecological constructions. If the structure doesn’t allow all this, we can build lightweight or ultra-light extensive green gardens too. To increase the ecological value of the building, photovoltaic panels can be also installed.

We are happy to help you with green projects, system solutions, estimates, and consultancy in the field.