MULTILAYER ASSEMBLY OF FLUID PERMEABLE GEOMATRIX MATERIAL FOR USE IN VEGETATED ECO-SYSTEM
A multilayer assembly ( 10 ) for use in a vegetated eco-roof or wall system includes layers of progressively permeable geomatrix material. Preferred embodiments of the multilayer assembly are composed of a filtration layer ( 22 ) of a nonwoven type positioned between a three-dimensional drainage/aeration base layer ( 24 ) and a growing media support layer ( 26 ). The sizes and structures of the pores of the base layer, openings of the filtration layer, and pores of the growing media support layer cooperate to permit flow of liquid from the growing media support layer through the base layer and form a gas flow gradient throughout the multilayer assembly. The gas flow gradient permits passage of gas from the base layer to the growing media support layer to mitigate moisture accumulation at the base layer.
1 . A multilayer assembly of fluid permeable geomatrix material for use in a vegetated eco-system, comprising:
a base layer having first and second major surfaces that define an interior of the base layer, the base layer characterized by compressive strength and by pores of sufficient sizes through which gas can pass and liquid can drain from one to the other of the first and second surfaces;
a growing media support layer of high strength porous material, the support layer characterized by sufficiently high strength to support solid root structure formation of vegetation growing in the growing media and by pores of sizes that cause liquid retention by and drainage from the support layer and permit passage of gas through the support layer;
a filtration layer positioned between the base layer and the growing media support layer, the filtration layer characterized by biaxial strength to preserve structural integrity of the multilayer assembly and by openings of sizes and structure to allow drainage of rain and excess irrigation water while retarding migration of soil and occurrence of biological fouling; and
the sizes and structures of the pores of the base layer, openings of the filtration layer, and pores of the support layer cooperating to permit flow of liquid from the growing media support layer through the base layer and forming a gas flow gradient throughout the multilayered assembly to permit passage of gas from the base layer to the growing media support layer to mitigate moisture accumulation at the base layer.
2 . The multilayer assembly of claim 1 , in which the filtration layer is of a nonwoven type.
3 . The multilayer assembly of claim 1 , in which the base layer comprises strands woven in an entangled mesh having generally planar first and second major surfaces that define an interior of the entangled mesh, the entangled mesh characterized by compressive strength and by pores of sufficient sizes through which gas can pass within the interior in transverse and lateral directions relative to the first and second major surfaces and through which liquid can drain from one to the other of the first and second surfaces.
4 . The multilayer assembly of claim 1 , in which the growing media support layer includes a nonwoven matrix of fibers.
5 . A vegetation roofing system, comprising:
a first set of multiple interconnected trays, the first set including trays having side walls that are unconnected to other trays in the first set;
a second set of multiple interconnected trays, the second set including trays having side walls that are unconnected to other trays in the first set;
the first and second sets arranged so that at least some of the unconnected side walls of the trays in the first set confront and are spaced-apart from at least some of the unconnected side walls of trays in the second set to provide an open space between the first and second sets; and
a multilayer assembly of fluid permeable geomatrix material positioned in the open space, the multilayer assembly including
a base layer having first and second major surfaces that define an interior of the base layer, the base layer characterized by compressive strength and by pores of sufficient sizes through which gas can pass and liquid can drain from one to the other of the first and second surfaces;
a growing media support layer of high strength porous material, the support layer characterized by sufficiently high strength to support solid root structure formation of vegetation growing in the growing media and by pores of sizes that cause liquid retention by and drainage from the support layer and permit passage of gas through the support layer;
a filtration layer positioned between the base layer and the growing media support layer, the filtration layer characterized by biaxial strength to preserve structural integrity of the multilayer assembly and by openings of sizes and structure to allow drainage of rain and excessive irrigation water while retarding migration of soil and occurrence of biological fouling.
6 . The vegetation roofing system of claim 5 , in which the filtration layer is of a nonwoven type.
7 . The vegetation roofing system of claim 5 , in which the base layer comprises strands woven in an entangled mesh having generally planar first and second major surfaces that define an interior of the entangled mesh, the entangled mesh characterized by compressive strength and by pores of sufficient sizes through which gas can pass within the interior in transverse and lateral directions relative to the first and second major surfaces and through which liquid can drain from one to the other of the first and second surfaces.
8 . The vegetation roofing system of claim 5 , in which the growing media support layer includes a nonwoven matrix of fibers.