Roof gardens are becoming increasingly popular, especially in cities. But how do you properly create a roof garden?
If you want to create a roof garden, you need a building permit. A roof garden must also have a direct irrigation system. The correct construction of a roof garden usually causes problems, in order to be able to subsequently ensure the irrigation of the plants over a large area and at the same time to achieve optimal thermal insulation for the residential building. That's why a roof garden is always built up in several layers.
Layered structure of a roof garden
First layer: waterproofing of the roof
The first layer is also considered the most important layer of a roof garden. It is used for sealing and therefore represents absolutely watertight protection for the residential building. At the same time, however, it also ensures optimal thermal insulation and is therefore rated as a positive insulation measure for the roof. Suitable for this is the use of weldable bitumen membranes, root-resistant roof garden tarpaulins made of plastic and the like. Specialist shops offer a wide variety of products for this purpose, which certainly always require a technical discussion before use.
Second Layer: Drainage Layer
A drainage layer is then planned for the roof garden in order to be able to transport excess water away from the roof via drainage pipes. The pipework usually leads from the roof towards the ground or sewage system. It is important that the drain lines cannot be blocked by garden waste (e.g. leaves).
Third Layer: Earth
Finally, earth is spread on the layers, which can not only level out any unevenness in the roof, but could also intentionally form unevenness.
Note: Expertise Required
The layered structure of a roof garden should always be carried out by a suitable specialist company due to the lack of specialist knowledge.
Plant roof garden
Once the layer structure has been successfully completed, the planting of a roof garden can begin. It should be borne in mind that each plant on a roof is always onerequires artificial irrigation. Therefore, you should primarily opt for easy-care, extremely robust plants that require little water. For example, boxwood, ivy, firethorn, some types of roses, butterfly bushes, bamboo, mahonia, etc. are suitable.
Tip: Roof plants should always be extremely hardy!
When planting, you also have to take into account that the roof garden is always under the influence of the wind. Therefore, all plants should be insensitive to wind. In addition, you must either fasten garden utensils (e.g. garden lighting, pergola, plant stakes, etc.) well or do without them entirely in the roof garden.
Alternative roof garden area
Alternatively, a roof garden can also be equipped purely with potted plants. The roof garden itself is laid with natural stones or a wooden terrace and then extremely stable potted plants are decoratively arranged on it.
Tip: Always use plant pots that have an integrated drainage system. In this way, the roof garden is not flooded unintentionally.
The advantage of pot plants is that many flowering ornamental plants, such as oleander and trumpet tree, can find their place on the roof. However, they must be kept in a frost-free room during the winter months.