No simple roof tiles. On roofs of new homes, we more often see moss or carefully selected vegetation. And not only that. Terraces or even entire roofs are decorated with gardens with grown bushes and trees.
So-called green roofs have many advantages:
To select a particular type of waterproofing foil, you need to know what type of roof garden you plan to establish:
The particular selection of plants should be discussed with a garden architect. Do not rely on your own gardening experience. The plants on the roof have to face completely different conditions than those on the flower bed.
What to avoid
When designing a green roof, check the load bearing capacity of the roof structure including its individual layers. Do not forget to count the weight of the soil as well as the weight of the plants themselves. Vegetation created with stonecrops, grass, and herbs represents the load of approx. 15 kg/m²; in case of bushes the value is 20 kg/m²; in case of trees the load is 150 kg/m².
Utility loads and loads derived from weather conditions must be of course considered as well (snow etc.). In case of a small point loading capacity of the thermal insulation in roof structure, the bearing layer must be applied under the LITHOPLAST® DREN studded membrane.
Select a suitable studded membrane according to the following table:
|Forma vegetace||Tloušťka vegetační vrstvy (mm)||Hmotnost vegetační vrstvy (kg/m2)||Vhodnost použití nopové fólie LITHOPLAST DREN|
|mech - rozchodník||30 - 50||90||+++||+||+||+|
|rozchodník - mech - byliny||50 - 80||144||++||++||+||+|
|rozchodník - byliny - tráva||80 - 120||216||++||++||+||+|
|tráva - byliny||120 - 160||288||++||++||++||+|
|tráva - byliny||80 - 100||180||++||+++||+||+|
|divoké byliny - dřeviny||150 - 250||450||+||++||++||+|
|trávník||100 a více||180||++||++||++||+|
|nízké trvalky a dřeviny||120 - 150||270||++||++||++||+|
|vyšší trvalky a dřeviny||150 - 200||360||++||++||++||+|
|keřové výsadby||250 - 350||630||+||++||+++||++|
|stromy||450 - 600||1080||+||++||++||++|
1. The base of the green roof forms a balanced and coherent substructure of the supporting structure. It is important that there be no depressions, protrusions or other inequalities.
2. This layer includes subbase iron-smoothed geotextile resistant against scrolling on anchoring screws. The subbase geotextile can be part of the insulating foil (IZOLTECH S 300).
3. Waterproofing is the third layer whose details must be flawlessly made. FATRAFOL 808/2.3 or FATRAFOL 810/1.5 is the most suitable waterproof insulation for green roofs. PENEFOL 800/1.5 is a conditionally usable membrane for small structures; this membrane must be integrated and concealed in the structure.
4. The LITHOPLAST® DREN 20/1.0 studded membrane is then placed on the surface. Fit the mounting joint with a one-sided adhesive butyl rubber band. If you use LITHOPLAST® DREN 40/ 1.5; LITHOPLAST® DREN 60/1.6 or LITHOPLAST® DREN 80/2.0 foils, place them at the joint and anchor them with a stapler.
5. A plastic drainage element with small studs PetexDren 400 or PetexDren 900 with large studs must be placed on the studded membrane. Place the drainage foil on the joint. Use light gravel, such as kemzit to fill bigger studs to increase the bearing capacity.
6. Further place the IZOLTECH K 300 filter geotextile with an overlap of 50 mm.
7. If the vegetation layer on the roof is thick, lay the drainage from the lightweight aggregate to the kemrazite.
8. The last layer is soil.