GREEN ROOFS AND TERRACE GARDENS - explains sections , methods , materials , issues and considerations for greening the roofs and sustainable development

1. Green roofs and Terrace
gardens
Ar S Kaalmegh
LAD College

2. Compare
Compare

4. The change can make
a difference ……..

5. Rooftop Gardens in history
 A roof garden is any garden on the roof of a building. Humans have grown
plants atop structures since antiquity. The garden may be on the roof of an
autonomous building which takes care of its own water and waste.

6. ROOF GARDEN SYSTEMS  UNTIL
RECENTLY…………. only for high-
end luxury projects for luxury
purposes
BUT NOW  most medium to large
projects are adopting roof garden
systems.
THEY ARE  considered ENERGY
EFFICIENT AND ECO-FRIENDLY and
have achieved A GREEN RATING,
Therefore green roof designing needs
a RIGHT APPROACH TO
DESIGNING AND WATERPROOFING
SUCH A SYSTEM.
IT WILL BE IMMENSELY HELPFUL
IF ATTENTION TO various
COMPONENTS is given WHILE
DESIGNING A ROOF GARDEN
SYSTEM.
As it WILL HELP IN PROVIDING A
DURABLE SERVICE LIFE FOR
SUCH GREEN ROOFS.

7. The green roofs / ROOFTOP GARDEN CONSTRUCTION
CONSISTS OF TWO EQUALLY IMPORTANT PHASED APPLICATIONS:
1. WATERPROOFING APPLICATION and 2. GARDEN ASSEMBLY.
( PLANTS AND SOIL )
The ultimate success of a rooftop garden depends largely on the
proper design and installation of both of these applications.
Rooftop Garden Construction -
Typically, a green roof begins with
an insulation layer, a waterproof
membrane to protect the building
from leaks, and a root barrier to
prevent roots from penetrating
the waterproof membrane.

8. GREEN ROOF :
 In the simplest terms, a green
roof is plants on top of a roof. It
is also known as a rooftop
garden.
A green roof typically consists
of the following components:
 An insulation layer,
 a waterproof membrane to
protect the building from
leaks.
 a root barrier to prevent
roots
from penetrating the
waterproof membrane;
 a drainage layer, usually
made of lightweight gravel,
clay, or plastic;
 a geotextile or filter mat
that allows water to soak
through but prevents erosion of
fine soil particles;
 a growing medium;
 Plants
 and, sometimes, a wind
blanket.

9.  Water proofing
 soil AND plants
2 COMPONENTS

10. THE
WATER PROOFING
ASSEMBLY

11. LOCATION AND SIZE OF
ROOF DRAINS
THE WATERPROOFING
SYSTEMS INTEGRATION i.e.
THE MEMBRANE AND
SYSTEM
THE TYPE OF SUPPORT TO
HOLD THE ADDED WEIGHT TO
THE BUILDING
There are three
waterproofing design
elements essential to
the success of the
system:

12. The support system

16. THE MEMBRANE

17. TYPES AND
METHOD OF
APPLICATION

18. Membrane Considerations
 The time and expense
associated with the repairs of
the membrane prohibit the use
of an "economical" 15- to 20-
year membrane system.
 The membrane system must
be durable enough to resist
mechanical damage from
gardening tools, the
penetration of plant roots, and
last without repair or
replacement for the life of the
building.
 It is essential that the designer
consider membrane systems that have
worked within this configuration in
previously successful applications.
 Membrane systems that are new to the
roofing industry do not have the
performance record required for these
applications.
 It may be advantageous to consider the
use of below-grade waterproofing
materials.
Photodegradable
netting
• Mats for soil
laying & plant
growth

19. Leachate from plants, fertilizers, and/or
composters comes in contact with
certain roofing membranes, leading to
possible membrane breakdown, if
membrane is not compatible with these
chemicals and organic compounds
THE DEGRADATION OF MEMBRANE

20. THE DRAINAGE SYSTEM

21. • A drainage layer is
usually made of
lightweight gravel,
clay, or plastic.
• The drainage layer
keeps the growing
media aerated in
addition to taking care
of excess water.
• Since a green roof
system covers the
entire roof, drainage
points must be
accessible from above
for maintenance
purposes.

22. • On top of the drainage layer,
a geotextile or filter mat
allows water to soak through
but prevents erosion of fine
soil particles.

23. LAYING THE
DRAINAGE SYSTEM

24. Clogging and water logging
 The roof drainage
system gets clogged
with sand, soil, or
vegetation, and
water is forced to sit
on the roof for long
periods of time,
allowing it to either
break down the
membrane or work
its way through the
seams.
 Some waterproofing
systems are
designed for holding
water, others are
not.

25.  Enhance
absorption of
water by
texturing,
terracing, planting
and ensuring
permeability of
surfaces,
especially on
slopes (which
should be as
gradual as
possible).
 NEVER …..direct
water to inlet
drains unless
essential due to
weight limitations
or inadequate
waterproofing.
EFFECTIVE AND CORRECT
USE OF RAINWATER FOR
ROOF GARDENS

26. • Direct the flow of runoff to
planted areas and
detention areas so that as
much water as possible
can be retained on the site.
Ideally, runoff could be
directed to a subsurface
reservoir to provide water
to plants on an "as-
needed" basis
• Retain and store rainwater in a covered
reservoir/cistern for later distribution to
plants (watering by hand or by a "leaky
pipe" irrigation system).

27.  Irrigation - Landscaping with
native plants is an
environmentally-beneficial
garden design.
 Still, the designer should
plan for the need to
supplement rainfall with
irrigation.
 Drainage - A key
environmental benefit of
rooftop gardens is that they
absorb rainwater and reduce
runoff to sewer systems.
 Still, any excess water not
absorbed within the garden
must be effectively drained
from the rooftop.
 Most gardens should be able
to use the existing rooftop
drainage system with only
minor modifications.
.

28. THE GROWING MEDIA AND
PLANTING BEDS

29. • The top layers consist of growing media, plants, and a wind blanket.
• The growing media is lightweight material that helps with drainage while
providing nutrients to the plants.
• A wind blanket is used to keep the growing media in place until the roots
of the plants take hold
1 2

30.  THERE ARE TWO BASIC TYPES OF
GREEN ROOFS: DEPENDING ON
TYPE OF GREEN COVER
1. INTENSIVE GREEN
ROOFS
 Require a minimum of
one foot of soil depth
to create a more
traditional rooftop
garden, with large
trees, shrubs and
other manicured
landscapes.
 They are multi-layer
constructions with
elaborate irrigation
and drainage
systems.
 Intensive green roofs
add considerable load
to a structure and
require intensive
maintenance.

31. 2. EXTENSIVE GREEN
ROOFS
1. Range from as
little as 1 to 5
inches in soil
depth, Adding less
load to a building.
2. Extensive green
roof systems also
generally require
less maintenance
than intensive
systems.

32. 3. Some green roof designs incorporate both intensive and extensive elements
……………………..
THERE ARE ALSO THE ULTRA EXTENSIVE WHERE SOIL COVER IS LESS
.

33. • Roof drains should have
proper covers / MEMBRANE
and planters lined with a layer
of filter cloth and gravel to
keep the soil from draining out
with the water.
• Often a layer of filter cloth or drainage
mat is laid over the whole roof, just on top
of the waterproofing, to avoid this
problem - especially if there is the
likelihood of soil being spilled from
planters, or sand removed from
sandboxes
• Planters could be placed on overflow
trays;
composters should never sit directly on the
membrane because of their requirements
for aeration and turning/working.

34. CONTAINERS
ON ROOF TOPS

35.  A Leak from containers and can
be located and accessed after
the garden is already in place .
 Moveable planters/containers,
modular walkways/surfacing
treatment, and
compartmentalized planting
beds could solve the problem of
leakage / seepage .

36. Design considerations for roof
top / terrace gardens
Maintenance Issues &

37. THE DESIGN AND DEVELOPING A CONCEPT

38.  Condition of the Roof –
 In general, the most cost-
effective time to construct a
rooftop garden is when the
roof needs to be replaced or
newly constructed.
 However, some types of
green roofs can be installed
on existing roofs.
• Occupancy and the
size of the garden-
• as they relate to and
impact on adjacent or
superimposed
occupancies
• occupant load
i.e. the number of people
allowed to occupy the garden
Newly constructed and Existing …..
OCCUPANT LOAD

39. Structural Capacity of the Roof –
Prior to designing and constructing
of a rooftop garden, determine if the
roof can support the additional
weight of soil and plants.
A licensed structural engineer or architect
must be hired to conduct a structural
analysis to ensure that the garden design
and the structural capacity are compatible.
The structural capacity largely will
dictate the type of rooftop garden
that can be built.
If the structural capacity is
sufficient, there could be a need to
obtain the proper permits before
proceeding.
Structural Considerations of
Rooftop Gardens :
2 aspects
1. The new loading exerted by the
garden
(the size and distribution of which can be
altered by altering the layout of the garden)
2. The load carrying capacity of the
structure
(which can be enhanced by increasing the
strength of existing load bearing members
or by adding new ones).
Occupant load also relates to
and impacts on --
structural loading requirements
exiting requirements

40. • Requirements for
exits on rooftops :
• types of exits
allowed .
• number of exits
• required distance
between exits.
• travel distance to
exits .
• sizes of exits and
areas defined as
"access to exits“.
• fire separations
between exits and
the rest of the floor
area .
• possible
requirements for fire
alarms, exit lights,
emergency lighting

41. Access to the Roof –
Consider what kind of access to
the roof will be needed during
and after the rooftop garden is
installed.
Cost –
In addition to the cost of
structural analysis, the
construction budget should
include any needed structural or
safety improvements, irrigation
systems, garden materials,
maintenance costs,
transportation and fees
associated with any ongoing
professional assistance and
permits.

42. Constructed Structures :
• Specific requirements for
structures/buildings on roofs,
should be considered
• also relating to effect on
overall building height , fire
rating of structural members

43. HEIGHT RESTRICTIONS AS PER ZONING LAWS WHICH ARE LOCAL

44. SIDE ROAD
PASADENA e.g.
MAIN ROAD
PASADENA
HYDERABAD e.g.
HEIGHT RESTRICTIONS
ZONING LAWS

45. NEW YORK

46.  Handicapped
accessibility and
Barrier Free Design,
either as a Code
requirement or as a
Client/User
requirement
• The placement of
elements such as
planters adjacent to
enclosures which
may reduce their
effective height
• Climability of
enclosures

47. • Requirements
for enclosures
i.e. guards,
railings,
parapets, walls
around rooftops,
terraces, and
balconies
required heights
• loading and
structural
stability of
guards and
railings

48. • Other
applicable
issues might
include: possible
modification of
window washing
anchors on the
roof .
• Possible UPGRADING of
washroom and service
requirements , drainage
and water-proofing
requirements etc .

49. • Planting beds / surfaces are often used to protect and
insulate roofing systems. Plantings in containers should be
used extensively in roof top gardens.
However, problems arise if,--- the membrane isn't protected from
•point-loading,
•shovels,
•shoe heels, and
•dropping equipment.
A protective drainage layer between
the soil and the membrane under planting
beds, and raised surfacing treatment for
non-planted areas should avoid damage.

50. • Treating small spaces
• Maintainable spaces
hassle free .
• Right balance of soft
and hardscapes.
• Understanding
importance of needs ,
Structure and views.
• Using light and shade.
• Using colour and
textures
• Making spaces
functional.
• Services

51. Benefits

52. GREEN ROOFS / TERRACE
GARDENS / ROOF GARDENS
are provided for one or few of
the following reasons :
1. Decoration
2. Improving and adding value
by aesthetic enhancement to
spaces
3. Improve air quality,
4. Conserve energy,
5. Reduce storm water runoff
6. Temperature control
7. May provide food
8. recreational opportunities.
9. architectural enhancement.

53. DECORATION

54. The garden's plants reflect heat, provide shade and help
cool the surrounding air through evapotranspiration,
which occurs when plants secrete or "transpire" water
through pores in their leaves. The water draws heat as it
evaporates, cooling the air in the process. Plants also filter
the air, which improves air quality by using excess carbon
dioxide to produce oxygen.
AIR QUALITY IMPROVEMENT :

55. AESTHETIC
VALUE

59. PRIVACY ON
THE TERRACE

60. Available gardening areas in cities are
often seriously lacking, which is likely
the key impetus for many roof gardens.
ENERGY CONSERVATION AND ARCHITECTURAL ENHANCEMENT

62. INCREASING PRODUCTIVITY :
GROWING VEGETABLES AND OTHER FOOD PRODUCE.

64. RECREATIONAL OPPORTUNITIES

66. Hydroponics, Xeriscapes and other
alternative methods can expand the
possibilities of roof top gardening by
reducing, for example, the need for
soil or its tremendous
weight…………OR ……
REDUCING
ENVIRONMENTAL
FOOTPRINT ..
HOW?

67. A concept for roof and
structure integration:
Eco friendly , climate control ,
site responsive

68. HAYHURST AND CO.: HANGING BASKET ROOF DESIGN
CONCEPT
WHY ???
THIS IS THE SITE .
LANDLOCKED ON
ALL SIDES .
ITS CALLED THE
Garden House, the
two-storey residence
is located in the De
Beauvoir area of
London's Hackney

69. THE PLAN :
G. FL. F. FL.
SECTION