Vegetation roofs

FATRAROOF Green – green roofs with a vegetation layer

The so-called green roofs are becoming an increasingly popular trend also in our country. Roof greenery features multiple positive functions, bringing benefits to both owners and the public.

There have also been ambitious business projects using large roofs to grow flowers and vegetables.  

Vegetation roof - FATRAROOF Green

1. Vegetation layer
2. Substrate
3. Filtration layer – geo-textile
4. Drainage layer (50 > 100 mm)
5. FATRAFOL 818 waterproofing membrane
6. Thermal insulation
7. Vapour control membrane
8. Roof supporting structure

Please see below the major positive effects of these roofs. Vegetation roofs suitably control water drainage in urban agglomerations, especially in industrial estates and shopping centres. This is of particular importance in large areas that have a significant impact on the landscape and change local water drainage conditions. The soil substrate with vegetation can contain up to 90 volume percent of water.

Positive functions of vegetation roofs

Vegetation roofs improve the thermal insulation of buildings. Air gaps and microbial movement in the soil allow a green roof to improve the thermal stability of the building by up to 25%. Green roofs are also pleasing to the eye, positively changing the urban appearance and creating new relaxation zones.

They further have an important sanitary function as they trap airborne dust, absorb carbon dioxide and reduce the noise level by up to 40 decibels. Last but not least, their economic effect is worth noting. Roof greenery not only saves energy costs but also protects the roof properties and extends the insulation durability by up to double. 

Vegetation layer of green roofs

Attention must also be paid to the types of greenery on the roof. If using the FATRAFOL 818 waterproofing membrane, two types of vegetation may be grown on the roof:

• Intensive (higher grass, annual plants, perennial plants, low- and mid-sized shrubs)
• Extensive (moss, lichen, stonecrop, houseleeks, arid grass).

Intensive greenery

Intensive roofs require greater care and are more costly to build than extensive roofs. They are suitable especially for large areas and representative buildings. Crops may be grown on intensive roofs.

Extensive greenery

In contrast, extensive roofs are easy to maintain and cheaper. The total costs of an extensive roof are approximately 10% higher than the costs of a non-vegetation roof.

Important aspects of vegetation roofs

To conclude, we wish to draw your attention to possible issues when building a roof garden. The main one is the roof structural strength, which may be affected by the heavier vegetation layer. In addition, greenery requires maintenance. The roof must be weeded and the greenery treated and fertilised at least once a year. Always make sure to choose the right waterproofing membrane as it must withstand increased load by the vegetation layer.

If using the FATRAFOL 818 membrane, you will build a perfectly functional green roof, which will put you on the right track to healthier surroundings and more environmentally friendly way of life (not only) in cities.