Vegetation element

A vegetation element for creating sod on artificial surfaces (such as roofs) is described. The vegetation element comprises a vegetation carrier consisting of synthetic and/or organic material for a vegetation, with the vegetation carrier consisting of at least one layer. The bottom layer of the vegetation carrier is attached to waterproof sheeting intended for sealing a roof to be sodded or designed as a rootproofing layer to prevent the roots from growing through.

It is known that vegetation elements are used to sod artificial surfaces 
such as the roofs of houses. An important component of a vegetation 
element is the vegetation carrier, which may be designed with one or more 
layers and is made of synthetic and/or organic material. The vegetation 
carrier comprises, among other things, a substrate and seeds for the 
plants or the plants themselves and their roots. 
The vegetation elements may be precultivated outside of their later site of 
use before they are installed on a roof. However, it is also possible to 
sod a roof directly on site and install the vegetation body directly on 
the roof. In the latter case, growth and cultivation of the plants take 
place on the roof itself. 
Regardless of the procedure described, it is necessary in any case to 
install the vegetation element with the vegetation carrier on the 
respective roof, preferably a flat roof or a roof with a slight slope. 
In practice, it must be recalled that the vegetation elements installed on 
a roof are exposed to outside influences in the form of erosion and wind 
suction forces, which can result in the vegetation elements being lifted 
up and blown away by the wind suction forces. This is especially true of 
thin, lightweight vegetation elements. However, mainly thin, lightweight 
vegetation elements are desired because then the roof is under a low load 
due to the low weight. 
The object of the invention is to create a vegetation element which can be 
installed easily on a roof to create sodding and which is protected from 
erosion and wind suction forces despite its low weight. 
The invention starts from the idea that the roof to be sodded is provided 
with a seal on its surface in the form of waterproof sheeting consisting 
of a suitable sealing material, e.g., PVC or bituminous roofing sheeting. 
In the past, the vegetation elements have been installed on this 
waterproof sheeting which is attached to the roof and usually has an 
underlayer of insulation. 
The invention now provides for attaching a roofing sheeting to the bottom 
of the vegetation element or to the bottom layer of the vegetation 
carrier, thus forming a unit consisting of the vegetation element and the 
roofing sheeting. This new vegetation element is installed on the roof, 
attaching the waterproof sheeting to the roof surface mechanically or by 
some other method in a known way, just as in the past the waterproof 
sheeting alone was attached to the roof. When the waterproof sheeting is 
attached to the roof, the vegetation element connected to it is protected 
from erosion and wind suction forces, so that thin, lightweight vegetation 
elements can also be used in the desired manner. 
When the new type of vegetation element is used, the conventional 
waterproof sheeting can be omitted from the respective roof, because it is 
already provided along with the vegetation element when the latter is 
installed. However, it is of course also conceivable to install the new 
vegetation element on roofs that have already been provided with a 
waterproof sheeting. 
In many cases the waterproof sheeting already present on a roof was not 
designed to be rootproof, so there is the danger that the roots of the 
plants of a vegetation element might grow through the sheetina. In this 
case, the invention provides for the waterproof sheeting which is attached 
to the bottom layer of the vegetation carrier to be designed as a 
rootproofing layer. 
The area of the waterproof sheeting is larger than the area of the 
vegetation carrier in this invention, so that the waterproof sheeting 
overlaps the vegetation carrier on two opposite sides, and there are free 
edges there. This is an advantage when several sheet-like vegetation 
elements are installed side by side. In the area of the free edges, the 
adjacent edges of the waterproof sheeting can be welded together. This 
yields a continuous closed waterproof sheeting for the roof. The free gap 
remaining under some circumstances between adjacent vegetation carriers 
can be filled subsequently with material of a vegetation carrier. 
The waterproof sheeting can be glued or even welded to the bottom layer of 
the vegetation carrier in an advantageous manner. 
Another expedient embodiment of the invention provides for a binder layer 
to be arranged between the bottom layer of the vegetation carrier and the 
waterproof sheeting, thus serving to attach the bottom layer of the 
vegetation carrier to the waterproof sheeting. 
An especially secure hold between the vegetation carrier and the waterproof 
sheeting is achieved by attaching it through the binder layer. The 
waterproof sheeting has very fine pores, while the vegetation carrier may 
be designed with large pores, and under some circumstances a connection 
between one surface with large pores and another with fine pores may not 
be reliably long lasting. The binder layer assumes a type of adapter 
function to adapt the different surface structures of the waterproof 
sheeting and the vegetation carrier, and it ensures a secure attachment of 
the waterproof sheeting to the vegetation carrier. 
Another embodiment of the invention provides for adhesives in the form of a 
dry adhesive to be arranged in or on the vegetation carrier. This yields 
the possibility of applying an additional vegetation layer to the 
vegetation carrier with the dry adhesive after the vegetation element has 
been installed on the roof. The dry adhesive is activated by adding water, 
and the additional vegetation layer is bonded with adhesive to the 
vegetation carrier below it or the layer below it, with the connection 
being maintained at least until a natural connection of the two layers is 
established in the sense of a biological reinforcement due to plant growth 
and the related root growth. 
Furthermore, it is expedient to provide fertilizers or soil conditioners 
and/or soil additives in or on the vegetation carrier. This especially 
promotes the growth of the plants. Furthermore, seeds for the plants which 
are to form the subseauent sod may also be provided in or on the 
vegetation carrier. 
In another expedient embodiment of this invention, the vegetation carrier 
serves as a rooting layer or as an irrigation and/or drainage layer, and 
it is provided to accommodate additional function layers. In these cases, 
it is thus the rooting layer or the irrigation and/or drainage layer of 
the vegetation carrier that is attached to the waterproof sheeting. Thus 
the rooting layer--the layer in which the roots of the plants essentially 
extend--or the irrigation and/or drainage layer may thus be followed by 
additional layers of the vegetation carrier having other functions.

Vegetation element 10 according to FIG. 1 comprises a vegetation carrier 12 
which is attached on its bottom side to a waterproof sheeting 16. 
Waterproof sheeting 16 either serves to seal a roof to be sodded or is 
designed as a rootproofing layer to prevent the roots from growing 
through. 
FIG. 2 shows the vegetation element according to FIG. 1 after cultivation 
is completed, so that vegetation element 10 is provided with sod 14 in the 
form of plan s. 
FIG. 3 shows a vegetation element 10 whose vegetation carrier 12 is 
designed in two layers with a top vegetation layer 22 and a lower drainage 
layer 24. In this case, the bottom layer, i.e., drainage layer 24, is 
connected to waterproof sheeting 16 which is in turn attached to a roof 26 
in a known manner and forms the sealing for roof 26. 
With the vegetation element illustrated in FIG. 4, a binder layer 28 is 
provided between vegetation carrier 12 and waterproof sheeting 16 to 
attach vegetation carrier 10 to waterproof sheeting 16. 
In general, the bottom layer of vegetation carrier 12 is attached to 
waterproof sheeting 16 by gluing or welding (i.e., with heat). 
It can be seen in the diagrams according to FIGS. 1-4 that the area of 
waterproof sheeting 16 is larger than the area of vegetation carrier 12, 
so that a free edge 18 and 20 remains on each side. These edges 18 and 20 
serve as welding edges when several strips of waterproof sheeting 16 with 
the vegetation element 10 on them are installed side by side on a roof and 
the individual strips of sheeting are welded together. 
Waterproof sheeting 16 may be constructed in a known way and may consist of 
a suitable sealing material, e.g., PVC, or it may also be designed as a 
bituminous roofing sheeting.