Green flat roofs: Benefits, prerequisites and servicing at a glance

The wonderful sight of a lush green area on your own roof is a real alternative to classic roofing. But that is not all: a green flat roof offers you several immediate advantages  and will create a direct connection between your building and nature.

With a green roof, you are bring a piece of greenery back to nature and fully protecting your roof covering entirely coincidentally. With foresight during design and planning, green roof coverings are easy to implement and quick to install. In this overview, we show you the benefits and prerequisites for green flat roofs, and all other important aspects for green roofs.

Benefits of a green flat roof

The demand for green flat roofs has grown and grown in recent years. This is not least due to the numerous advantages that a green roof brings with it. If you opt for an extensive green flat roof, annual servicing and maintenance work is also minimal. This means you will enjoy the many benefits in a state of calm and can simply relax.

Benefit 1: improved thermal insulation in winter and heat protection in summertime

Thanks to flat green roofs, you can improve the thermal insulation of your house, permitting you to cut your energy costs and bills. What acts as improved insulation in wintertime, additionally also acts as heat protection during summertime. During the summer months, the green flat roof covering functions as a natural climate control system, keeping the inside of the house pleasantly cool.

Benefit 2: Relief for drains and sewers, natural air humidification and filtering pollutant

The plants of green flat roof coverings can absorb fine dust from the air and filter pollutants out. Thus, green roofs can help reduce fine dust pollution in cities and municipalities. In addition, the plants in green flat roof coverings gradually release their stored water. This transpiration humidifies the air, creating a natural cooling effect. This effect contributes to improving ambient atmospheric conditions and providing a pleasant climate for humans and animals. Storing rainwater relieves the burden on drains and sewers. Excessive water produced during heavy rainfall, which can no longer be absorbed by plants, is retained and released into the drains and sewers with a time delay.

Benefit 3: Additional protection for waterproofing roofs

Green roof coverings on flat roofs extend the life of your roof compared to ‘bare’ roof surfaces, with no green covering. The additional layer of green roofing protects the existing waterproofing on the roof against influences from wind and weather, heat and UV radiation.

Benefit 4: Contribution to preserving biodiversity

The number of waterproof surfaces in individual cities and municipalities continues to grow and grow. Therefore,  it is important to create environmental compensation areas and surfaces, in order to return habitats to plants and living creatures. With green flat roof coverings, you are returning a piece of greenery to nature and making an important contribution to preserving biodiversity. Bees, wild bees, butterflies and other insects can be found settling on a green roof - so it is not only people who enjoy green roof coverings.

Prerequisites for green roof coverings

In order for you to benefit from the numerous advantages, you should consider a few important points even during the design stage and prior to construction of the flat roof. For extensive green flat roof coverings, you must consider an additional weight per unit area of approx. 90kg/m² - 120kg/m². This additional weight is essentially determined by fitting the substrate of the green roofing build-up.

The additional weight per unit area will be even higher if you opt for an intensive green flat roof covering. Make sure the static engineering requirements and load-bearing capacity of your roof are  checked by a suitable specialist. If you decide to have a green roof covering retrofitted to a flat roof at a later date, you must also take the condition of current waterproofing of the roof into consideration. Only proceed with a green roof covering on a flat roof where flawless, root-resistant and watertight roof seals are present, which comply with FLL guidelines. The scope of green flat roofing options solutions is determined by the condition of your roof.

Subsidies for green flat roofing solutions

The wise variety of grants and subsidy programmes available in Germany, make it almost inconceivable you will not lose the overview in the funding jungle. Some subsidy measures for environmentally friendly and energy-efficient buildings also deal with green roof coverings on new-builds and renovation projects. Increasingly, cities and municipalities in Germany promote green roofs by means of direct financial subsidies or indirect measures, such as reduced charges for rainwater.

Build-up for a green flat roof covering

The build-up of a green flat roof covering consists of a total of 6 individual layers which are concealed beneath the wonderful appearance of lush greenery. When installing a flat green roof, first and foremost static engineering parameters of the roof structure must be taken into account. In addition to static engineering, there should also be a minimum inclination  of approximately 2%. Please note that if you are unsure about the static conditions of your roof, it is essential you seek expert advice from a roofing contractor.