Installation lightweight green roof

Please find below a written instruction for the installation of a lightweight green roof. This installation instruction is suitable for roofs with a maximum roof pitch of 10 degrees. Click on the button below to download this instruction as a PDF.

Download the installation instructions here 


STEP 1 – Clean the roof
Clean the roof and remove dirt, waste or other materials. Check that the roof covering is not damaged, to make sure that the roof is waterproof.



STEP 2 – Apply root barrier foil (optional)
If the roofing is not root-resistant, it is necessary to use a root barrier foil. Apply the root barrier foil in the direction of the arrow. Also cover the raised roof edge. Make sure the foil joins well by means of an overlap of 50 cm.


STEP 3 – Apply drainage layer
Roll out the drainage sheets to the roof edge, perpendicularly over the root barrier foil (see the direction of the arrow). If necessary, prepare the cutting of the drainage to size on the ground or take measures to cut safely. Never cut directly on the roofing.

The installation instructions for the drainage supplied are described on the product sheet. This sheet can be requested at Sales Support;

Cut a piece out of the drainage layer at the location of the rainwater downpipe(s). Cover the rainwater downpipe with a wire balloon guard, leaf trap or inspection pit.

STEP 4 – Apply separation profile
The separation profile serves as a separation between the green roof and the gravel strip. Place the profile at least 20 to 30 cm from the roof edge, with the base on the side of the gravel strip.



STEP 5 – Apply substrate roll
Roll the substrate roll perpendicularly over the drainage rolls (see the direction of the arrow). Ensure that the substrate roll joins well without overlap. Completely saturate the substrate roll with water before installing the vegetation mats.


STEP 6 – Apply vegetation blankets
Carefully roll out the vegetation blankets perpendicularly over the substrate roll (see the direction of the arrow).
Start with the end of the vegetation blanket on top. Carefully roll the end of the blanket back and make sure it is in the correct position at the start of the track. If necessary, cut or saw the blanket to the right length.

Tip: use a sturdy serrated knife or saw. Make sure that the vegetation blankets join well without overlap. Any bare patches can be filled with residual pieces of the vegetation blanket.

STEP 7 – Apply gravel
Apply the gravel between the green roof and the roof edge. Bring the gravel layer to the same level of the green roof.


STEP 8 – Irrigate
Water the vegetation blankets immediately after installation, until the substrate roll is completely water saturated. This is necessary for the rooting of the vegetation blankets in the underlying substrate layer. Water the green roof regularly when the roof is installed during a dry period.


STEP 9 – Maintenance and fertilization
The maintenance and fertilization advice for a Sedum roof can be read in the document Maintenance advice Sedum roof.

View other green roof structures