Enrich Green Roof Soil

Transcription

1 Enrich Green Roof Soil

2 Introduction Architects and Landscape Architects are devising innovative ways to incorporate more green space into current residential, commercial and industrial development areas in order to benefit the environment and enhance our surroundings. With newly created Roof Foliage, previously unused surfaces can have a functional value, a design value and a biodiversity and wildlife value. One of the most exciting aspects of green roofs, from both a design and an environmental point of view, is their potential to support life in situations that would otherwise be largely barren and sterile. In high-density urban areas, where so much green space is lost at ground level, this becomes a vital function. A green roof is an extension of the existing roof which involves a high quality water proofing and root repellent system, a drainage system, filter cloth, a light weight growing medium and plants.

3 The Green Roof or Green Garden Green roof and green-roof garden both belong to a type of roof that supports vegetation. In general, there is a clear distinction between the two types. The roofs are labelled as extensive roof-greening or intensive roof-greening. Intensive roof greening is associated with Green Gardens. The terms extensive and intensive describe the grade of maintenance needed for a specific cultivation system and its degree of sustainability. Green roofs are known as extensive because they should require only little maintenance and be self regenerating. The following criteria can be used to characterize two different forms of Green Roofs: Extensive Green Roof Intensive Green Roof Maintenance Low High Irrigation No Regularly Plant communities System build-up height Moss-Sedum-Herbs and Grasses mm Lawn or Perennials, Shrubs and Trees mm on underground garages > 1000 mm Weight Low High Use Ecological protection layer Park like garden

4 The Natural Solution Enrich manufacture a lightweight roof soil that provides nutrients and a stable structure for the roots to anchor in. The lightweight roof soil is a blend of lightweight aggregates, compost and soil. A key consideration of the growing media is that it comprises of sustainable material that forms a living biological machine complete with insects, worms, fungi and mycorrhizae. What distinguishes the roof soil from natural soil? It is a blend of organic and mineral particles of varying sizes and composition. Over 50 percent of the roof soil serves as channels to allow free movement of air and water. Normal soils will either have good pore space but have a poor ability to hold on to nutrients or they will either retain so much moisture that it becomes waterlogged causing excessive loading and stress to the roof structure. There is a difference in the volume of components used in each of the Enrich roof soil blends, this is ultimately dependant on the depth of the planting area. For deeper planting (intensive) areas, more compost and soil is added. This mix is heavier and allows a higher water-holding and nutrient capacity in order to support the larger plants.

5 The growing medium for extensive roof, is typically made up of a mineral-based mixture of sand, leca, organic matter, and some soil. This varies in depth between 5-20 cm. Due to the shallowness of the growing medium and the extreme desert-like microclimate on many roofs, plants must be low and hardy, typically alpine, dry land, or indigenous. Typically the plants are watered and fertilized only until they are established, and after the first year, maintenance consists of two visits a year for weeding of invasive species, safety and membrane inspections.

6 Heat Expanded Clay This innovative material is specifically source by Enrich. It is a special lightweight substance made from expandable Lamstedt clay processed then fired and expanded in a special process without chemical additives in temperatures of 1,150 Celsius. This firing process allows the expanded clay to be strong enough to maintain open pore space within the soil to allow free air and water movement. However contrary to this, the hollow cavities in the pellets absorb and store water for the plants. Being a natural product LECA contains no harmful substances, it is inert with neutral ph, The granules are resistant to frost and chemicals, and will not break down in water. They are also noncombustible and have excellent sound and thermal insulation properties.

7 Installing a Lightweight medium by 1 cubic meter bags Installing a Sedum blanket A wild flower and grass roof

8 Benefits to Use of Enrich lightweight roof soil The increasing popularity of Roof top planting has being largely due to the versatility of each of its functions: o Storm-water management o Urban development o Open space planning o Ecological and biodiversity o Protection of roof surfaces o Urban heat island Storm-water management the special properties of the growing medium and the plants help to retain the rainwater. This delays the run-off, which helps reduce the potential for flooding and water damage. In addition, vegetation and substrate can absorb a range of pollutants including nitrogen, phosphorus and heavy metals such as cadmium, copper, lead and zinc. In many cities around the world it has been recognised that the most significant ecological advantage of roof planting is storm water management. It is hard to come up with average figures of performance, however, roughly 50-60% of rainfall can be expected to be retained by an extensive green roof. Trials carried out at Trent University in Nottingham found that roofs fitted with a vegetation layer growing on a lightweight aggregate substrate layer considerably reduced the volume of rainwater discharged. Expressed as a percentage of the unplanted control roof, the planted roof retained 100% of a 3 mm rainfall, 80% of a 3-23 mm rainfall and for one period where 41mm of rain fell over 47 hrs, 73% of the rain was retained. Obviously, the planted roof is not designed to act as a sponge and eventually the roof will become saturated and discharge water. The table below shows the drainage requirements of a 4500m² car park if green roofed or traditionally surfaced: (CRM rainwater consultants, Zinco)

9 Traditional Roofing Approach Green Roof Approach 27 No. 150mm diameter outlets 1 No. 150mm diameter outlets 162m above ground pipe work 6m above ground pipework 400m underground pipework 3m underground pipework Onsite water retention required No additional water storage required Urban development the creation of new development sites swallow up green spaces on the ground. Incorporating a green planted area softens the bland look of buildings. This can reduce community resistance to new development. There is a potential for local, regional, and national market exposure, depending on the uniqueness of the project. Green roofs can reduce energy requirements; By lowering the ambient temperature of the roof's surface, green roofs can reduce summer cooling needs by as much as 26%. Conversely, green roofs provide great insulation and can reduce heat loss during winter months by that same 26%. Green roofs superior insulating qualities help reduce noise pollution caused by traffic and airplanes. Open space planning green planted areas can be employed as amenity space and for aesthetics. Depending on access to, the area can be used for crèche, meeting and recreation. The space could be used by employees thus potentially improving productivity. The aesthetic appeal can increase the value of the property and the marketability of the building. Green roofs improve air quality; one square meter of leaf surface supplies enough oxygen, through photosynthesis, to supply one person's requirements for an entire year. Since the foliage in plants binds dust, green roofs further improve air quality by reducing dust. Some of the most comprehensive research carried out on the effects of urban vegetation on particulate pollutants was with regard to parkland trees in cities. Such plants were found to filter out up to 85% of suspended particles (Lohmann, 1990)

10 Ecological and biodiversity Growing media comprises of sustainable material that forms a living biological machine complete with insects, worms, fungi and mycorrhizae. This creates a natural habitat for flora and fauna to colonise and flourish. Green roofs can provide new opportunities for urban horticulture. The potential for roof top gardens to further enhance bio diversity in urban areas is immense and such gardens can provide important habitat for a wide range of insect species which in turn support birds, bats and other wildlife. Well planned and carefully planted roof top gardens will bring immense environmental benefits as well as providing attractive leisure areas, especially where space is at a premium and where conventional gardens are not possible. The benefits of such green spaces are well documented. They improve air quality and absorb carbon. They bestow many health giving benefits, especially by providing a natural haven for relaxation in an otherwise busy urban setting. Protection of roof surfaces Roof foliage provides noise insulation, insulation from summer heat, insulation from coldness and evident of the mechanic and physical wear of the roof structure by equalising temperatures extremes and by stopping the ageing process of the roof shell from UV rays. Urban heat islands- Traditional building materials soak up the sun's radiation and reflect it back as heat, making cities at least 2-8 C hotter than surrounding areas. This phenomenon is referred to as urban heat islands. Green roofs help reduce this effect by lowering roof top temperatures by 15º-30 C. The impervious surfaces of cities such as concrete, tarmac and the wide variety of roof surfaces soak up solar energy and reradiate it as thermal infrared radiation (heat). The result of this is that cities are warmer both day and night than the surrounding countryside. This can have profoundly negative effects on air quality in the city. Production of some pollutants can be higher and the flushing out of others is reduced as the inflow of clean cool air is reduced by the thermal conditions.

11 Conclusion Ireland is going to be increasingly dominated by climate change, both human induced and natural, the effects of the built environment on the global environment are going to be of major importance practically, economically and politically. The natural disasters that increasingly fill the headlines are only partly natural very often what happens is the result of human destruction or perturbation of natural environments; flash floods caused by impermeable concrete paving being simply one of many examples. While green roofs may hold and slow down runoff from a roof, the water must go somewhere. Often it is taken away by a drainage system, and forgotten about, this in many ways is wasteful of a resource. Utilizing, will become increasingly important in years to come. Reference: Living Roofs Green roofs for Healthy Cities Books Planting Green roofs and Living Walls. Nigel Dunnett and Noel Kiingsbury

12 Specification for Extensive Rooftop substrate Production Made from special blend of lightweight aggregate and organic compontents Grain sizes 0 20mm weight kg/m2 saturated ph Organic content 10-15% by mass Typical Substrate mm Depth Typical Plant Sedums grasses mosses herbs and succulents communities Permeability >12-3m/s Frost and fire yes resistance Specification for Intensive Rooftop Substrate Production Made from special blend of lightweight aggregate and organic compontents Grain sizes 0 20mm weight kg/m2 saturated ph Organic content 10-25% by mass Typical Substrate mm Depth Typical Plant Shrubs Grasses Trees communities Permeability >20-3m/s Frost and fire yes resistance