Das Gründach

The green roof

A green roof is a flat roof that may be systematically planted with, for example, varieties of sedum, moss, or grass, but also with perennials and even bushes and trees. A green roof has many advantages. It improves the appearance of a building, and in big cities especially it serves as a 'substitute garden', thus boosting the residential value of the property. More than that, green roofs are advantageous in terms of construction physics and ecology. Plants form a natural shield for the waterproofing. They compensate temperature extremes and ward off environmental influences, such as rain or hail. Since this reduces the load on the waterproofing, roofs need to be refurbished less often, which makes not only the purse happy. At the same time, planted roofs positively influence the environment through, for example,  

  • Continuous air humidification: plants store a large proportion of the rainwater and allow it to evaporate later on.
  • At the same time, they trap dust and pollutants, thus improving the quality of the air.
  • Natural climate regulation: in winter, a green roof acts as a heat insulation layer, while in summer, it protects the interior from high temperatures. The result: well-tempered rooms and reduced energy costs.
  • The green roof as a habitat: planted roofs create living space for animal species. 
  • Enhanced noise protection: green roofs reduce noise reflection by up to 3dB. Interior noise abatement improves by up to 8dB.
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green roofzoom
green roofzoom
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Extensive vs. intensive planting

There are two ways of planting a roof: extensively and intensively. The distinction is based on the kind of plant involved. The plants that are mostly used on extensively planted roofs include grasses, mosses, herbs, and succulents. They are economical to buy and easy to care for because they largely survive and develop on their own. The quickly form a tight-woven carpet of plants and soon become an ecologically effective protective shield. Intensively planted roofs are often called garden roofs which, like an ordinary garden, may be planted with any kind of plant: bushes, trees, and even entire lawns. This wide variety of options increases the maintenance effort: intensively planted roofs should be regularly watered, trimmed, and cared for.

Extensively planted roofs

Extensively planted roofs are covered by low-growing vegetation in a manner that is close to natural. The generally closed vegetation cover consists of plants that rarely need watering and will withstand high temperatures. These are chiefly moss and grass varieties, although different varieties of sedum also appear frequently. Extensively planted flat roofs are not used for traffic as they only need to be walked on once or twice a year for inspection purposes.


Intensively planted roofs

Intensively planted roofs are also called roof gardens. In this version, numerous plant varieties including perennials, bushes, and even lawns and trees are given space on the flat roof. Intensively planted roofs need to be regularly supplied with water and nutrients, which is why the maintenance effort is greater in this case. From this, it follows that intensively planted roofs are always walkable. Thanks to the numerous design options they offer, like combinations involving terraces, seating arrangements, and walkways, intensively planted roofs increase the residential value of a building and decorate densely built-up areas with a piece of nature.

green roof - DELTA®-FLORAXX TOP
Green roof - DELTA®-FLORAXX
Dörken GmbH & Co. KG

Dörken GmbH & Co. KG
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E-Mail    bvf@doerken.de

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