A Green roofing is a roofing of any building that is partly or completely covered with live vegetation. The vegetation is usually planted over a waterproof materials. The green roof structure does not make reference to the rooftops that are merely shaded green. Green roofs may also include additional levels of root barriers and irrigation systems. In the event where crops are grown up in pots and then positioned in roof tops, they are not considered to be true renewable roofs. Roof top ponds are another form of inexperienced roof and are being used to treat grey drinking water (Little, par. 1). Grey drinking water is any water that is used in the home for the purposes of washing except water from toilets. Normal water from laundry, sinks and showers is all referred to as grey normal water. This drinking water usually would go to waste but it may be reused for other purposes, especially irrigation. Grey water may therefore be run to roof backyards. Green roofs are also referred to as roof gardens and eco-roofs. Little says that roofing gardens provide several purposes for a building such as absorbing rainwater, providing insulation for the building, creating habitat for animals, and also lowering urban conditions thus lowering heat island effect (Little, par. 1).
There are two types of inexperienced roofs: intensive renewable roofs and considerable inexperienced roofs. Intensive green roofs are fuller and can support a wider variety of plants. They are simply heavier and require a whole lot of maintenance. They are created in such a way that they are accessible. The other type of green roofs is called extensive green roofs. These types of green roofs are covered by lighter vegetation and are better to maintain than the extensive green roofs. They are simply mainly developed for cosmetic purposes, but likewise have various advantages to the environment.
Green roofs can also be used to make reference to the types of roofs that may use some type of green technology such as cool roof structure with photovoltaic modules. Photovoltaic modules are interconnected assembly of solar cells. The main reason for the solar power is to convert the solar energy into electricity.
Population growth in the world today is happening at a very rapid rate. Many metropolitan areas on earth are speedily becoming highly urbanized with the engineering of properties and constructions in close contact with each other. Increased building of concrete structures has led to the increased loss of green cover therefore creating a great deal of environmental issues such as metropolitan heat island effect. This has generated a substantial upsurge in air heat in urban areas. The energy intake has increased as an result of heat island effect. Vegetation and vegetations play a very vital role in trapping mud and dust allergens in the air. Crops also utilize carbon dioxide in the process of photosynthesis and generate air and glucose substances during the day. This helps in reduction of carbon dioxide in the air as well as increasing the quantity of oxygen in the air. Along the way of metropolitan development, trees are decrease at a very higher rate. This contributes to cutting down of the quality of air as degrees of carbon dioxide increase and oxygen levels reduce. Regarding to Dowdey (para 3), places where there are no rooftop gardens, rainwater flows very fast from the structures' roofs into the sewer and in cases where the sewer cannot cope with the amount of water streaming from the roofing tops, floods appear.
The main cause of island temperature effect in the urban areas is the absorption and retention of solar heating in properties and other concrete constructions resulting in the environment heat in such areas becoming warmer than in the rural areas. Upsurge in heat means that the air conditioning load of these buildings will have to be increased. Which means that more energy will be needed by the conditioners that will in return release more warm exhaust air into the outdoor thus aggravating the urban heat island result. Roof gardens have been proven to lower the surface temperature and mid-air heat greatly. Little expresses that the main reason why renewable roofs lower these temps is basically because, they cover heat absorbing areas of the roof tops as well as the evapotranspiration cooling down ramifications of the plant life.
Roof vegetation improves the air quality by acting as a filter to snare air borne dust particles. A roof covering that offers a high temp tends to make a thermal draft appealing to dust particles from the avenues. The renewable roofs have been found to average the thermal draft thus minimizing the temp difference between the roofing tops and the streets. Green roofs also help reduce the formation of smog. Smog is very sensitive to high temperature ranges and the fact is the higher the temperature, the higher the attentiveness of smog. Regarding to Dowdey, vegetation through the procedure of photosynthesis absorb skin tightening and and release air in to the atmosphere thus enhancing the quality of air (Dowdey, par. 4).
The green roof structure helps to filter almost all of the heavy metals and nutrition present in rainwater. This is very beneficial in cities where precipitation is gathered for domestic consumption.
Roof gardens keep most of rainwater on the roof through the various layers and significantly reduce the peak discharge flow rate into the storm normal water drainage system. This can help to reduce the risk of flash flooding.
When surfaces absorb a lot of solar high temperature, urban warmth island is the producing effect. Therefore causes a considerable upsurge in the atmospheric temperatures within the metropolitan centers. This will likely subsequently lead to numerous energy intake for cooling tons. Roof gardens help to absorb a whole lot of solar high temperature that would otherwise raise the atmospheric temperature. Cooling lots will therefore not be asked to such a great level and hence decrease in energy consumption would be the beneficial end result. Green roofs also assist in reducing heat loss and energy intake in winter conditions (Kuhn, p 5).
Green spaces are extremely good for people living and employed in the metropolitan centers. These spaces help in promoting biodiversity, softening the building's environment, and assisting peoples' mental and physical health. Green roofs increase the value of the green space by giving accessible renewable space. Green roofs are very appealing to those who look at them. Some renewable roofs can be created for visitors to enjoy (Dowdey, par. 7).
If 50% of the roofs in Tokyo were protected with roof gardens, a study exhibited that air temperature could be reduced from between 0. 11c to 0. 84c. Translation of the statistics into real money value projected that about $1. 6 million each day in electricity invoice could be achieved as energy personal savings. Kuhn (p 6) says that about 15% of total annual energy saving may be accomplished with roof gardens. Cooling loads can be considerably reduced up to 80% resulting in downsizing of air-con systems which would greatly improve cost savings in capital assets. A reduction of peak roof structure thermal copy value of up to 80% make the rooftop tops a viable replacement for thermal insulation.
According to Dowdey, roofing gardens protect this proofing membrane as well as the roof top top surfaces from the harmful ramifications of the ultra violet rays. A lot of the drinking water which would normally reach the roof covering material creating dampness and rust is either considered by the vegetation or retained by the water evidence membrane (para 8). Coverage of water proofing membrane and the roof covering material stretches their life to about four times their average life. This particular proof material and the roof material itself will not be tampered with in the process of regular replacement. This greatly enhances the life span expectancy of the roof materials. Green roofs also play a very important role in guarding roofs from real human traffic, heavy particles and dust debris. Which means that the roofs are safe from being tampered with by people (Dowdey, par. 9).
Proper planning installing a green roof covering greatly reduces the negatives which may be supported with it. However, some types of renewable roofs do have more demanding structural expectations than others. Some existing buildings can't be retrofitted with certain kinds of green roofs due to weight load of the substrates and the vegetation which go over the allowed static loading, also referred to as the external make applied to a fixed position for a particular period of time. Depending on the kind of the green roof structure, the price tag on maintenance could be high. Some types of renewable roofs especially the intensive green roof require a very strong drinking water proofing material to prevent water and roots from penetrating this particular proof membrane. Installing adequate normal water proofing materials and root barriers takes a considerable amount of money. The vegetation on the backyards requires special fertilizers which can often be too costly (Kuhn, p 7).
Green roof structure are therefore very good for real human not only in terms of environmental protection but also in conditions of overall economy. Their advantages are incredibly many as compared to their drawbacks. The roles performed by green landscapes employ a great impact inside our lives. Adjustment of the surroundings through cutting down the island warmth, managing storm water, lowering air and water pollution and creating a wildlife habitat are a few of the renewable garden's environmental benefits. Green roofs have also been shown to raise the roofing life as well as reduce energy costs. Considering the benefits associated with the roof landscapes, the cost factor may be looked at the least for roof backyards to be widely adopted.
- Dowdey, Sarah. Exactly what is a Green Roof structure?, 2009. Retrieved on November 27, 2009 from http://science. howstuffworks. com/green-rooftop. htm
- Kuhn, Monica. Roof Gardening, 1996. Retrieved on November 27, 2009 from http://www. nea. gov. sg/cms/sei/PSS23slides. pdf
- Little, John. Green roof structure training, 2009. Retrieved on November 27, 2009 from http://www. livingroofs. org/livingpages/greenroofintro. html