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PROJECT 1 GREEN ROOF

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CEWB221 HYDRAULICS

PROJECT 1

GREEN ROOF TECHNOLOGY

SECTION: 01

GROUP MEMBERS:

1)SIVASANGKARAN A/L CHINNA SWAMI CE092006

2) SURENTHAR A/L SANDRASEKARAN CE0919433) SARNIYA A/P KESAVALOO CE0918314)

DATE OF LABORATORY SESSION: 16/06/2014

DATE OF REPORT SUBMISSION: 23/06/2014

LECTURER: DR. HAFIZ BIN ZAWAWI


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TABLE OF CONTENT

NUM TOPIC PAGE

1 INTRODUCTION

2 LITERATURE REVIEW

3 WHAT IS GREEN ROOF

4 HISTORY OF GREEN ROOF

5 TYPE OF GREEN ROOF

6 COMPONENTS OF GREEN ROOF

7 ADVANTAGE OF GREEN ROOF

8 DISADVANTAGE OF GREEN ROOF

9 CONCLUSION

10 REFERENCE


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INTRODUCTION

The layers of a green roof must, like any roof, accommodate drainage An aerial view of most

urban areas shows swathes ofasphalt,blacktar and gravel-ballasted rooftops. Heat radiates off

of the dark roofs, and water rushes over the hard, hopefully impermeable surfaces. Yet, there is a

new trend that breaks up the monotony of common roofs: green rooftops. Long popular in

Europe, green rooftops have begun to appeal tohome owners,businesses and even cities as an

attractive way to promote environmentalism while solving the problems of conventional roofs.

Green roofs supplement traditional vegetation without disrupting urban infrastructure -- they take

a neglected space and make it useful.

Green roofs last longer than conventional roofs, reduceenergy costs with natural insulation,

create peaceful retreats for people and animals, and absorb storm water, potentially lessening the

need for complex and expensive drainage systems. On a wider scale, green roofs improve air

quality and help reduce the Urban Heat Island Effect, a condition in which city and suburbandevelopments absorb and trap heat. Anyone who has walked across a scalding parking lot on a

hot, summer day has felt one effect of an Urban Heat Island and protect the building from the

elements with a waterproof membrane. But they also must create a growing area and potentially

provide support,irrigation and root protection barriers while staying as light as possible.
http://healthguide.howstuffworks.com/asphalt-cement-dictionary.htmhttp://healthguide.howstuffworks.com/tar-remover-dictionary.htmhttp://home.howstuffworks.com/real-estate/buying-home/house-buying.htmhttp://money.howstuffworks.com/business-channel.htmhttp://home.howstuffworks.com/green-living/how-to-conserve-energy-at-home.htmhttp://home.howstuffworks.com/irrigation.htmhttp://home.howstuffworks.com/irrigation.htmhttp://home.howstuffworks.com/green-living/how-to-conserve-energy-at-home.htmhttp://money.howstuffworks.com/business-channel.htmhttp://home.howstuffworks.com/real-estate/buying-home/house-buying.htmhttp://healthguide.howstuffworks.com/tar-remover-dictionary.htmhttp://healthguide.howstuffworks.com/asphalt-cement-dictionary.htm


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LITERATURE REVIEW

Vandermeulen, Valerie; Verspecht, A., Vermeire, B., Van Huylenbroeck, G., Gellynck, X.

(November 30, 2011)."The use of economic valuation to create public support for green

infrastructure investments in urban areas

Increasing urbanization has created pressure on land use. Today more and more land inurbanized areas is used for housing, industry, community services or other economic functions.

However, green spaces have a proven positive effect on people living in the neighborhood of

green spaces, as well as on people working or recreating in the urbanized area. Therefore, greeninfrastructure investments have been put high on the agenda in many European countries. In

order to convince the public and other stakeholders of the usefulness of these kind of green

investments, it is necessary to give a correct, understandable and easily repeatable method to

value the investment. The current article describes a model that can be used to put the value ofgreen infrastructure investments into economic terms. Evaluating the project at site scale and

regional scale will give a complete overview of all direct, indirect and use values of the

investment. By using costbenefit as well as multiplier analyses the monetary values can beestimated. The article shows that using this model helps to justify policy's support for and

investment in green space.

"University of TorontoNews@UofTGreen roofs in winter: Hot design for a cold

climate".17 November 2005.

Everyone studies how green roofs operate in warm conditions, says Brad Bass of the U of TCentre for Environment. No one else has looked at winter design. Bass analyzed a test roof

built in Ottawa by Karen Liu of the National Research Councils Institute for Research in

Construction, to offer the first conclusive data that winter green roofs can help reduce heat lossand energy consumption during cold months. The results are currently on display in the DesignFor the Cold exhibition at the Chalmers Design Centre, Design Exchange.
http://www.sciencedirect.com/science/article/pii/S0169204611002428http://www.sciencedirect.com/science/article/pii/S0169204611002428http://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://web.archive.org/web/20080411230309/http:/www.news.utoronto.ca/bin6/051117-1822.asphttp://www.sciencedirect.com/science/article/pii/S0169204611002428http://www.sciencedirect.com/science/article/pii/S0169204611002428


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WHAT IS GREEN ROOF

A green roof or living roof is aroof of abuilding that is partially or completely covered with

vegetation and a growing medium, planted over awaterproofing membrane.It may also include

additional layers such as aroot barrier anddrainage andirrigation systems.Container gardens onroofs, where plants are maintained in pots, are not generally considered to be true green roofs,

although this is debated. Rooftop ponds are another form of green roofs which are used to

treatgrey water.

Green roofs serve several purposes for a building, such as absorbingrainwater,providinginsulation,creating a habitat for wildlife, increasing benevolence and decreasing stress

of the people around the roof by providing a more aesthetically pleasing landscape, and helping

to lower urban air temperatures and mitigate theheat island effect.There are two types of green

roofs: intensive roofs, which are thicker, with a minimum depth of 12.8 cm, and can support awider variety of plants but are heavier and require more maintenance, and extensive roofs, which

are shallow, ranging in depth from 2 cm to 12.7 cm, lighter than intensive green roofs, andrequire minimal maintenance.
http://en.wikipedia.org/wiki/Roofhttp://en.wikipedia.org/wiki/Buildinghttp://en.wikipedia.org/wiki/Waterproofing#Construction_waterproofinghttp://en.wikipedia.org/wiki/Root_barrierhttp://en.wikipedia.org/wiki/Drainagehttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Container_gardenhttp://en.wikipedia.org/wiki/Greywaterhttp://en.wikipedia.org/wiki/Rainwaterhttp://en.wikipedia.org/wiki/Building_insulationhttp://en.wikipedia.org/wiki/Heat_island_effecthttp://en.wikipedia.org/wiki/Heat_island_effecthttp://en.wikipedia.org/wiki/Building_insulationhttp://en.wikipedia.org/wiki/Rainwaterhttp://en.wikipedia.org/wiki/Greywaterhttp://en.wikipedia.org/wiki/Container_gardenhttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Drainagehttp://en.wikipedia.org/wiki/Root_barrierhttp://en.wikipedia.org/wiki/Waterproofing#Construction_waterproofinghttp://en.wikipedia.org/wiki/Buildinghttp://en.wikipedia.org/wiki/Roof


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HISTORY OF GREEN ROOF

Modern green roofs, which are made of a system of manufactured layers deliberately placed over

roofs to support growing medium and vegetation, are a relatively new phenomenon. However,

green roofs orsod roofs in NorthernScandinavia have been around for centuries. The modern

trend started when green roofs were developed in Germany in the 1960s, and has since spread to

many countries. Today, it is estimated that about 10% of all German roofs have been

greened.Green roofs are also becoming increasingly popular in the United States, although

they are not as common as in Europe.

A number of European Countries have very active associations promoting green roofs, including

Germany, Switzerland, the Netherlands, Norway, Italy, Austria, Hungary, Sweden, the UK, and

Greece. The City of Linz in Austria has been paying developers to install green roofs since 1983,

and in Switzerland it has been a federal law since the late 1990s. In the UK, their uptake has

been slow, but a number of cities have developed policies to encourage their use, notably

London and Sheffield.

Rooftopwater purification is also being implemented in green roofs. These forms of green roofs

are actuallytreatment pondsbuilt into the rooftops. They are built either from a simple substrate

(as being done inDongtan)or with plant-based ponds (as being done by WaterWorks UK Grow

System and Waterzuiveren.be Plants used includecalamus,Menyanthes trifoliata,Mentha

aquatica,etc)

Several studies have been carried out in Germany since the 1970s. Berlin is one of the most

important centers of green roof research in Germany. Particularly in the last 10 years, much more

research has begun. About ten green roof research centers exist in the US and activities exist in

about 40 countries. In a recent study on the impacts of green infrastructure, in particular green

roofs in the Greater Manchester area, researchers found that adding green roofs can help keep

temperatures down, particularly in urban areas: adding green roofs to all buildings can have a

dramatic effect on maximum surface temperatures, keeping temperatures below the 19611990

current form case for all time periods and emissions scenarios. Roof greening makes the biggest

differencewhere the building proportion is high and the evaporative fraction is low. Thus, the

largest difference was made in the town centers.
http://en.wikipedia.org/wiki/Sod_roofhttp://en.wikipedia.org/wiki/Scandinaviahttp://en.wikipedia.org/wiki/Greywater_treatmenthttp://en.wikipedia.org/wiki/Treatment_pond#Rooftop_treatment_pondshttp://en.wikipedia.org/wiki/Dongtanhttp://en.wikipedia.org/wiki/Calamus_(palm)http://en.wikipedia.org/wiki/Menyanthes_trifoliatahttp://en.wikipedia.org/wiki/Mentha_aquaticahttp://en.wikipedia.org/wiki/Mentha_aquaticahttp://en.wikipedia.org/wiki/Mentha_aquaticahttp://en.wikipedia.org/wiki/Mentha_aquaticahttp://en.wikipedia.org/wiki/Menyanthes_trifoliatahttp://en.wikipedia.org/wiki/Calamus_(palm)http://en.wikipedia.org/wiki/Dongtanhttp://en.wikipedia.org/wiki/Treatment_pond#Rooftop_treatment_pondshttp://en.wikipedia.org/wiki/Greywater_treatmenthttp://en.wikipedia.org/wiki/Scandinaviahttp://en.wikipedia.org/wiki/Sod_roof


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TYPES OF GREEN ROOF


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INTENSIVE GREEN ROOF

Intensive Green Roof, Garden Roof, Roof Garden - An intensive green roof system is

characterized by its variety of vegetation ranging from herbaceous plants to small trees

with professionel maintenance and advanced green roof irrigation systems. A typical growingmedium depth of an intensive green roof is 6 inches or more. Intensive green roofs offer a great

potential for design andbiodiversity. This system supports everything from smallpersonal/home

gardenstofull scale public parks. Plant selection and design greatly affects the maintenancerequired for the upkeep of these roofs. Rooftop farms, urban roof farms or vegetable farms on

roofs are clearly intensive green roofs and require higher nutrient applications and focused

maintenance.

Examples of Intensive Green Roofs

Cruise Ships

While the green roof on the cruise ship may only have a 5 inch profile, the irrigation and workinvolved in maintaining the warm and cold season grass lawn to pristine standards earns it the

classification of an intensive green roof system. The green roof features a 1 inch drainage layer

with4 inches of growingmedium and specially selected sod mats. Subsurface irrigation and a24 hour computerized monitoring system ensures these lawns stay luxuriously lush for guests to

enjoy whether they are sailing in St. Petersburg, Russia or the Caribbean.
http://www.greenrooftechnology.com/biodiversityhttp://www.greenrooftechnology.com/biodiversity


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Peggy Notebeart Museum

The Peggy Notebeart Museum features a series of green roofs ranging from a sloped extensive

green roof to an intensive green roof. The intensive portion, features a 2-10 inch drainage

layerand a2.5 to 8 inch growing media layer,exhibits diverse examples of habitats. The

incredible set up of this green roof supports flora ranging from wetland plants to small trees.

Chicago City Hall

The Chicago City Hall green roof profile ranges from 4 inches to 2 feet in depth on a Geofoam

landscape. This roof amply supports over 150 plant species, including woody shrubs, vines and

trees. The plants were selected for their hardiness, native origins and their hardiness to the

extreme temperatures and wind of the city by Landscape architects. Jrg Breuning consulted this

project in all regards and developed Green Roof solution tailored for this unique location - and

the first green roof in the USA according modern green roof technology.


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EXTENSIVE GREEN ROOF

Extensive Green Roof - An extensive green roof system is characterized of its vegetation,

ranging from sedums to small grasses, herbs and flowering herbaceous plants, which need little

maintenance and no permanent irrigation system. The growing medium depth for an extensive

green roof system is typically 6 inches or less. These systems are ideal for efficient storm water

management with low maintenance needs. Extensive green roofs are very cost efficient. Please

read the case study "The Economics of Green Roofs from the Perspective of the Commercial

Client" in ourgreen roof case study section.Extensive green roofs are ideal for integrated

PV/Solar systems like the Sun-Root system.

Examples of Extensive Green Roofs

Bronx County Courthouse

The Bronx County Courthouse features a 1 inch drainage layerwith a 2.5-3 inch deep growingmedium profile. The green roof is composed of a mix of sedums and hardy herbs, with a

sweeping crescent of small grasses. Despite the 10 story elevation and center city location, the

green roof has attracted a variety of wildlife over the years.

Swarthmore College David Kemp Hall

The David Kemp Hall at Swarthmore College is a beautiful example of an extensive green roof

and is one of the best maintained green roofs in the area. The green roof features a 1 inch

drainage layer and a 3 inch growing media profile. The roof features a mix of sedum and herbs

with a few experimental plants such as a small colony of cacti.
http://www.greenrooftechnology.com/case-studieshttp://www.greenrooftechnology.com/Solar_PV_Greenroofshttp://www.greenrooftechnology.com/Solar_PV_Greenroofshttp://www.greenrooftechnology.com/Solar_PV_Greenroofshttp://www.greenrooftechnology.com/Solar_PV_Greenroofshttp://www.greenrooftechnology.com/case-studies


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COMPONENTS OF GREEN ROOF


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Components

Root barrier (not shown) goes directly on the roofing membrane; however, it is not

necessary if the membrane itself has root barrier protection.

Protection mat is often also a moisture retention mat designed to maximize water

retention for plant health.

Drainage layer moves and stores water. The type varies greatly depending on the climate,

water retention criteria, and thickness of the media which could crush some drainage types.

Drainage may be a layer of special drainage media or made of synthetic material.

Separation fabric allows water to penetrate but stops the media from entering the

drainage system.

Growth Media is engineered to be lightweight, to not compact over time and to have the

right amount of organic matter to support the plants. All media should follow standards for

green roofs.

Plants should be chosen for the specific roof conditions, media thickness and local

climate. They can be planted as cuttings, plugs or installed as a vegetated mat which

increases the cost. It is important that the customer understands that if cuttings or plugs are

used, the roof will take two years to fully mature with 80% coverage.

Wind protection can be temporary or permanent depending on the conditions of the site

and will not be visible once plants reach maturity.


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ADVANTAGES OF GREEN ROOF

There are many financial benefits that accompany green roofing

Green roofing can extend the lifespan of a roof by over 200% by covering the waterproofing

membrane with growing medium and vegetation, this shields the membrane from ultra-violet

radiation and physical damage

It is estimated that the installation of a green roof could increase the real estate value of an

average house by about 7%.

Reduction in energy use is an important property of green roofing. By improving the thermal

performance of a roof, green roofing allows buildings to better retain their heat during the

cooler winter months while reflecting and absorbing solar radiation during the hotter summer

months, allowing buildings to remain cooler.

Depending on the region in which a green roof is installed, incentives may be available in the

form of storm water tax reduction, grants, or rebates. The regions where these incentives willmost likely be found are areas where failing storm water management infrastructure in place,

urban heat island effect has significantly increased the local air temperature, or areas where

environmental contaminants in the storm water runoff is of great concern.

Storm Water Amelioration

Green roofs store rainwater in the plants and growing mediums and evaporate water into the

atmosphere. The amount of water that is stored on a green roof and evaporated back is

dependent on the growing medium, its depth and the type of plants used. In summer greenroofs can retain 70-80% of rainfall and in winter they retain between 25-40%.

In Green roofs also reduce and delay run off during times of heavy and prolonged

precipitation. A study in Germany has shown that during a 10mm rainstorm, 200 litres of

rainwater fell on an 18m2 extensive green roof and only 15 litres actually passed from the

roof to the ground.

Green roofs, therefore, reduce the impact of run off on the storm water drainage system, and

reduce the likelihood of local flooding.


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Health

There is a growing body of evidence that the visual and physical contact with natural

greenery provides a range of benefits to people. These include both mental benefits (such as

reduction of stress) and physical benefits (including the provision of cleaner air). Access to

green space can bring about direct reductions in a person's heart rate and blood-pressure, andcan aid general well-being

The thermal benefits that green roofs provide may also have indirect benefits for people

living or working within the buildings.

It is possible that the green roof reduced the fluctuation of daily mean temperatures within

the upper levels of the building, and/or the vegetation helped cool and moisturise in-going air

near ventilation ducts.

The provision of specific accessible green roof space for future workers appears to be

gaining currency, and could help off-set the likely constraints of green space provision on theground.

Energy Conservation improved thermal performance

Green roof systems are recognised as providing greater thermal performance and roof

insulation for the buildings they are laid on. This can vary depending on the time of the year,

and the amount of water held within the system.

Cooling [summer] Poorly protected and insulated roofs can lead to substantial overheating of

spaces beneath them. This can lead to the need for increased air-conditioning. A green roof

not only acts as an insulation barrier, but the combination of plant processes [photosynthesis

and evapotranspiration] and soil processes [evapo-transmission] reduces the amount of solar

energy absorbed by the roof membrane, thus leading to cooler temperatures beneath the

surface.

Thermal Insulation [winter] Green roofs can help to reduce heat loss from buildings during

the winter when root activity of plants, air layers and the totality of the specific system create

heat and thereby provide an insulation membrane. However the efficiency of green roofs as

thermal barriers is dependent on the amount of water held within the system. Water retention

can increase the amount of heat lost through the system and therefore any efficiency gains

are dependent on daily conditions. It is therefore difficult to provide accurate figures on the

net effect of green roofs on energy efficiency during the winter months.


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Noise and sound Insulation

The combination of soil, plants and trapped layers of air within green roof systems can act as

a sound insulation barrier. Sound waves are absorbed, reflected or deflected. The growing

medium tends to block lower sound frequencies whilst the plants block higher frequencies.

The amount of sound insulation is dependent on the system used and the substrate depth. Agreen roof with a 12 cm substrate layer can reduce sound by 40dB and one of 20 cm by 46-

50dB.

Standard Unvegetated 33dB

Vegetated [dry] 41dB

Vegetated [wet] 51dB

100mm Concrete Wall 43dB

This suggests that a green roof can reduce sound by 8dB compared with a conventional roof

system. This could be particularly important in areas of high noise pollution such in the

approaches to airports, as these levels are sufficient to provide noise insulation to buildings

under aircraft flight paths.

Recycled Materials

A number of materials used in green roofs are from recycled sources, such as the membranes

and growing mediums, such as crushed porous brick, which is used by some suppliers. In

London, uniquely, there has been a move to use recycled secondary aggregate as the growing

medium, preferably from the original site.

This reduces the need for waste disposal to landfill and reduces the transport miles/distances

for used for disposal of waste. This meets UK government targets for the reuse of secondary

aggregates and where reuse from site can reduce the impact of lorries in terms of importation

and exportation of materials.


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DISADVANTAGES

Initial cost of installing a green roof can be double that of a normal roof

The additional mass of the soil substrate and retained water places a large strain on thestructural support of a build

large amount of added weight as well as the added cost of reinforcing buildings to be ableto support such weight

Some types of green roofs do have more demanding structural standards especially inseismic regions of the world.

The wildlife they attract may includepestinsects which could easily infiltrate aresidential building through open windows.
http://en.wikipedia.org/wiki/Pest_(organism)http://en.wikipedia.org/wiki/Pest_(organism)http://en.wikipedia.org/wiki/Pest_(organism)http://en.wikipedia.org/wiki/Pest_(organism)


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