Oct 25, 2014
INTRODUCTION 50% of world’s population living in a metropolitan areas - 60% expected by 2030 due to population growth
80% of global carbon dioxide emission attributed to cities
Urban heat island effect - increased energy requirement - increased smog formation
Definition:-
A green roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems.
NECESSITY OF GREEN ROOF The groundwater resources in India are
greatly diminishing by several centimeters
per year and are not being replaced. As
global warming becomes more and more of
an issue, and towns and cities expand,
green space is becoming more and more
important. Green roofs are particularly
useful at filtering out pollutants from the
air and as such, purifying it.
TYPES OF GREEN ROOF
Green roofs are generally categorized as:-
(i) Extensive
(ii) Intensive
EXTENSIVE GREEN ROOF
Extensive Green Roofs are well suited to roofs with little
load bearing capacity and sites which are not meant to be
used as roof gardens.
The growing medium, typically made up of a mineral-
based mixture of sand, gravel, crushed brick, leca, peat,
organic matter, and some soil, varies in depth between 5-
15 cm
Extensive green roofs are often not accessible and are
characterized by:
• low weight,
• low capital cost,
• low plant diversity, and
• minimal maintenance requirements.
Extensive Green Roof
EXTENSIVE GREEN ROOF
INTENSIVE GREEN ROOFThese roof are also referred to as high-profile – They look like
traditional roof gardens because a much wider variety of plant
material can be included since growing media depths are increased.
These roofs generally require more effort for the tending of plants,
whereas the term extensive roofs call for a more passive approach.
The growing medium is often soil based, ranging in depth from 20–
60 cm.
Intensive green roofs are often accessible and are
characterized by:
• Deeper soil and greater weight,
• Higher capital costs,
• Increased plant diversity, and
• More maintenance requirements
INTENSIVE GREEN ROOF
COMPARISON OF EXTENSIVE &
INTENSIVE GREEN ROOF
Extensive Green Roof Intensive Green Roof
Maintenance Low High
Irrigation No Regularly
Plant communities Moss-Sedum-Herbs and
Grasses
Lawn or Perennials, Shrubs
and Trees
System build-up height 60 - 200 mm
150 - 400 mm on
underground garages > 1000
mm
Weight 60 - 150 kg/m2 180 - 500 kg/m2
Costs Low High
Use Ecological protection layer Park like garden
SYSTEM OF GREEN ROOFComplete systems
Modular systems
Precultivated vegetation blankets
COMPLETE SYSTEM
MODULAR SYSTEM
PRECULTIVATED VEGETATION BLANKET
CONSTRUCTION OF GREEN ROOF
Points to be Considered Before Installing a Green Roof
(i) SLOPE
(ii) CLIMATE
(iii) STRUCTURE
(iv) MATERIALS
(v) WATERPROOFING LAYER
(vi) DRAINAGE LAYER
(vii) GROWING MEDIA
BUILDING OWNER BENEFITSEnergy savingsRoof membrane protection and life extensionSound insulation PUBLIC BENEFITSUrban heat island effect Storm water retentionReduction of dust & smog levels
PRIVATE BENIFITSIncresed roof lifeReduced noise levelsHeat shield
BENEFITS
The main limitation of green roofs is the higher initial
cost.
Some existing buildings cannot be retrofitted with certain
kinds of green roof because of the weight load of the
substrate and vegetation exceeds permitted static loading.
Depending on what kind of green roof it is, the maintenance
costs could be higher, but some types of green roof have little
or no ongoing cost.
LIMITATION OF GREEN ROOF
ROOF GARDEN vs. GREEN ROOF
A roof garden is actually very different from a Green
roof, although the two terms are often and incorrectly used
interchangeably. A roof garden is an area that is generally
used for recreation, entertaining, and as an additional
outdoor living space for the building's residents. It may
include planters, plants, dining and lounging furniture,
outdoor structures such as pergolas and sheds, and
automated irrigation and lighting systems. A roof garden re-
establishes the relationship between man and nature that can
be lost in urban environments.
COST Given various assembly types and project descriptions
costs can range from Rs.5500/- Sq.m. to Rs.6900/- Sq.m.
or more. These figures include membrane through plants.
Cost per square meter depends on many factors:
i) The size and slope of the roof,
ii) Depth and complexity of the system,
iii) Height and accessibility from the ground,
iv) Cost of labor, and need for specialized elements,
such as drains, railings, pavers, slope stabilization
measure, etc.
MAINTENANCEMaintenance activities that must be performed on a green
roof are weeding, replanting, and inspections of the waterproof membrane.
Depending on whether the green roof is extensive or intensive, required plant maintenance will range from two to three yearly inspections to check for weeds or damage.
Eventually, after 30-50 years, the membrane will have to be replaced.
Green roofs provide numerous benefits to the building itself as well as the environment and society as a whole, but lack widespread awareness.
Future developments in materials and installation techniques should lower upfront costs, but further subsidies are needed to make the technology accessible to the general population.
In present state as land is becoming scarce in urban areas, storm water drainage problem is growing, and energy prices are increasing for building heating and cooling, green roofs are becoming increasingly viable.
CONCLUSION
CONCRETE SLAB
DRAINAGE LAYER (SHINGLE - 0.05m)
WATERPROOFING LAYER(0.01m)
FILTER LAYER (PUMICE STONE - 0.02m)
GROWING MEDIA (0.08m)
VEGETATION,PLANTS
DRAINAGE SYSTEM(P.V.C. PIPE)
Material Cost Unit
Waterproofing0.01m
Rs. 100/- Sq.m.
Pumice stone0.02m
Rs. 175/- Sq.m.
Shingle0.05m
Rs. 500/- Sq.m.
Soil0.08m
Rs. 50/- Sq.m.
Elephanta Lawn0.02m
Rs. 270/- Sq.m.
P.V.C. pipe0.02 m(diameter)
Rs. 20/- L.S.
Plants Rs. 80/- Nos.
Tray Rs. 1200/- Nos.
Total = Rs. 2400/- Sq.m
Labour 10% Rs. 240/-
Transport 5% Rs. 120/-
Overhead 5% Rs. 120/-
Total = Rs. 2880/- Approximately Rs. 3000/-
Sq.m
Any question?
GREEN ROOFPrepared By:-
0701031 – SACHINDRAKUMAR P. MISHRA
0701032 – SWAPNIL S. MOHITE
0701033 – NILIMA S. MORE
0701034 – TEJASWINEE V. NAIK
0701035 – KETAN S. NAVALE
0701036 – YOGESH P. PAREKH
0701037 – KARAN K. PATIL
0701038 – MUKESH V. PATIL
0701039 – DNYANESHWAR S. PAVASKAR
GUIDED BY:-
PROF. S. V. CHAUDHARI
SUPPORTED BY:-
PROF. R. B. RAO