Greening the garage roof - what effort does it make?


With the construction of a garage always a piece of green space is lost on the property. Green roofs could compensate for this loss. The requirements for green roofs on the garage roof and how they are carried out can be found in this article.

Intensive and extensive green roofs

Before planning a roof greening on the garage roof, one must first decide whether one would like to carry out extensive or intensive green roofs. In some cases, it can certainly be interesting to build a roof garden or a green roof terrace on the garage roof during intensive greening.

Intensive roof greening

Intensive greening is the more elaborate option. Shrubs and perennials are used here on the roof for planting, even lawns and even small trees are possible. It is therefore a real garden, with full soil and the need for a sufficient water supply. As a result, the costs are often very high.

Simple intensive greening

Here, the plants used are chosen so that no constant additional irrigation must be done. They are also lighter than fully fledged intensive green areas, and have a significantly lower maintenance costs.

extensive Green

Extensive greening is much easier and usually requires little care and no irrigation. Instead of plants, they are mainly used for:

  • Moose
  • grasses
  • ferns
  • Succulents (water-storing plants)

Advantages of green roofs

Green roofs have numerous advantages that should also be considered in advance. The gain in green space can often even be decisive that you can still build a relatively large garage on the property when the roof is greened.

Conditions for green roofs

First, it must be checked whether the roof is sufficiently tight and sufficiently stable. The construction of green roofs may also be made only on those flat roofs that are suitable for green roofs. What suitable usually the roofer knows. Otherwise, additional layers must be applied to the roof seal.

Load capacity requirements

Green roofs bring a considerable weight to the roof. The following basic weight loads for the roof and body heights can be assumed:

  • Type of roof greening
  • Weight load per square meter
  • acting weight / m²
  • installation height
Extensive0.5 - 1.5 kN / m²approx. 50 - 150 kg per m²6 - 15 cm
Simply intensive1, 5 - 3.0 kN / m²about 150 - 300 kg per m²15 - 25 cm
Intensivemore than 3.0 kN / m²over 300 kg per m²over 25 cm

This creates high static loads that the roof must be able to remove safely. In any case, the roofer or the structural engineer must decide whether an existing flat roof on the garage can carry these loads at all.

Tips & Tricks

When used as a roof garden, there are other regulations that must be observed: such as a surrounding railing, which meets the safety requirements, and corresponding fuses for an ascent or descent on the garage roof (safety stairs).


Video Board: Duke's Green Garage