Green Roofs FAQ

Here you can read answers to the most frequent questions about our green roofs.

In order to lay out our sedum planters, a watertight membrane is required, which is specially approved to lie beneath a green roof.

You can consult your felt supplier about this.


No, fortunately not. Our 60 mm sedum planters can be used on roofs with a pitch of up to 25 degrees. If the roof has a steeper pitch, one must use our 80 mm planters. We can supply green roofs for roofs of up to 45 degrees pitch, but, depending upon the pitch, additional safety arrangements must probably be installed.

In the case of pitches steeper than 15 degrees, support profiles, which hold the sedum planters in place, must be used.

Please consult Nature Impact for guidance regarding support profiles.

No, green roofs from Nature Impact are not maintenance-free. The sedum plants are placed in relatively low planters with growing medium and should be fertilised 1-2 times annually. There may be a need to remove small branches and twigs or other unwanted items, that shade the plats [See more in our guidelines for maintenance here].

At the end of the winter, there is not much nourishment in the soil. At this time, the plants need fertiliser, water and warmth to regenerate and to get chloroplasts going again. This is the explanation for the red colour. When it becomes warmer, which one notices in the course of spring and the roof is fertilised manually, the colour of the plants changes and they become green and vigorous again.

Sedum plants are extremely hardy. They can stand a dry summer. Typically, one will find that not so many flowers appear during a dry period. The plants are then using energy to survive and not to multiply, which flowers are designed for. In dry [periods, the roof becomes reddish, but as soon as the rain comes, the plants will change colour and become green and vigorous again.

This may vary. When we produce our sedum planters, it is with cuttings from 12-16 different plants. This is to ensure the best growing conditions on the roofs, where the sedum plants may experience many different environments. They should be able to withstand wind from the North Sea and heat from towns and may also ends up being placed in full shade. Amounts of flowers may be reduced in the course of the year, therefore we start with many plants in the planters. Irrespective of where our planters are placed, we are therefore sure that there will be sedum plants that survive and bloom profusely from May to September.

We do not sell to individuals, but you can contact your local carpenter, roofer or timber merchant. They can quite certainly help you further with your wish.

When we have delivered the sedum planters, the green roof should be laid within 48 hours.

The wight is always measures soaking wet, and thus the heaviest weight. Nature Impact’s 60 mm sedum planters weigh 50 kg per m2. The 80 mm sedum planters weigh 65 kg per m2 .

It is always a good idea to check the load-bearing capacity of the rafters before one lays a green roof.

Read more

Green Roofs

Nature Impact Roof – system solution for sedum roofs. Ensures drains, growth medium and plants in one system.


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Green Roof Case

Green roofs from Nature Impact can be installed on almost every roof construction. Read about the green roofs on the Solrødgaard Treatment Plant here.