With a green roof, you’re not only doing something good for the environment. It also contributes to a pleasant microclimate (outside and inside) and transforms even unsightly sheds and garages into small green oases. In this article, you’ll learn what forms of green roofs there are, which surfaces and plants are suitable, and what you need to make a green roof yourself.
What is the point of a green roof in the first place?
Whether a green roof looks more beautiful than a conventional roof construction is probably in the eye of the beholder. However, many people find the sight of the living green much more pleasant than a classic roof covering with tiles and the like. Especially in densely built-up cities, green roofs offer a welcome change from the widespread gray in gray. In addition to its aesthetic effect, a green roof also has many other positive properties: it contributes to climate protection. It promotes biodiversity by creating an insect-friendly habitat. It counteracts the negative effects of increasing land sealing. It reduces fine dust pollution and serves as heat protection on hot days. Properly constructed, it protects the roof structure from the elements, contributing to a longer service life. Tip: As an alternative to fully concrete parking lots, grass pavers also support the natural water cycle and help maintain habitats for insects.
For which roofs is a green roof suitable?
Not all roofs can be greened, but as long as the slope is not too steep, even gable and shed roofs can be planted. Green roofs are particularly easy to implement on roof pitches between five and fifteen percent. Steep roofs with a greater slope require more effort to prevent the planted substrate from slipping and to ensure an adequate water supply for the plants.
If you want to green the roof of a house, garage or shed, you should also clarify in advance how much load the roof structure can bear. Depending on the structure of the green roof, the additional weight in rain and snow can add up to several hundred kilograms per square meter. For roofs that cannot bear this much load, only a much lighter, extensive green roof can then be considered.
Extensive or intensive green roofs?
Anyone who deals with the subject of green roofs will sooner or later come across the terms extensive roof greening and intensive roof greening. Extensive green roofs are particularly easy to maintain and are also suitable for less massive roofs. Here, a thin substrate layer (up to 15 centimeters) is applied, which is particularly suitable for low-maintenance plants such as mosses, grasses and succulents. They largely maintain themselves after the green roof is built.
An intensive green roof is more complex to implement than the extensive variant and can be planted (almost) like a conventional garden and even used for growing vegetables. The roof structure underneath must be designed accordingly for a greater load-bearing capacity and the maintenance effort for an intensive green roof is higher.
Which plants are suitable for a green roof? Depending on the form of the green roof, different plants come into question. While an intensively greened roof can even be planted with perennials, woody plants and other tall-growing plants, mainly smaller, low-maintenance plants that can also cope with longer dry periods come into question for extensively greened roofs. These include: Succulents (e.g., black wall pepper, white stonecrop and snow carpet), Mediterranean herbs (e.g., lavender, oregano, rosemary and sage) and hardy wild plants (e.g., speedwell, lady’s mantle and yarrow). Here’s a multi-page list of perennials and grasses for extensive planting.
Doing green roofs yourself Not every green roof variant is easy to implement yourself. For roofs with a steep slope and for people who do not have the confidence to build their own, it is advisable to call in a specialized horticultural company. If you are a skilled craftsman and would like to build the green roof (e.g. on a garden shed or garage) yourself, you can find the individual components in DIY stores or at specialized retailers. The following materials are required: root-proof waterproofing Protective fleece Drainage layer Filter layer Substrate Plants The green roof is applied to the roof surface layer by layer and finally equipped with the selected succulent shoots, seeds and seedlings. In this video, the individual steps for the construction of an extensive green roof are clearly illustrated:
It is even easier to do the green roof yourself if you use green roof prefabricated elements that can be placed directly on a protective fleece and already contain drainage, filter, substrate and plants. You can find them, for example, at suppliers such as SedumDach or sempergreen. What does a green roof cost? Depending on the solution chosen, the cost of a green roof ranges from 40 to 140 euros. You can also find a lot more information at the Bundesverband GebäudeGrün e.V.. In our books you can discover numerous small and big ideas for a better world and practical tips for your nature-oriented garden:
Have you already gained experience with a green roof? Then share your tips with us and feel free to share an inspiring photo of your green oasis below the post!
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
Please if you have any questions leave them on the article and i will get back to you personally.