Post on 16-Apr-2017
transcript
Field Research
17th- 29th May,2012
Recommendations for Permanent Shelter in Coastal
Districts of Lower Sindh
Engr.Zubair Hashmi’s study as consultant
Handicap Pakistan funded this study
Research Methodology• Physical Investigation & Observation• Interviews a)Internal b) External• Focus Group Discussions a) Beneficiaries b) Self Builders c) Non-Beneficiaries d) Artisans (Carpenters/Masons)• Participatory work on MODEL • Coordination Meetings• Construction Material Source & Availability Survey
Coordination
• Coordination Officer ,UN OCHA• DDMA Representative, Badin • Shelter Cluster District Badin Focal• Operations Officer .Hands Organization• Site Supervisor , HF• Provincial Coordinator, IDC
• Logistic Officer, Tear Fund• Technical Lead, IOM Hyderabad• Chief Engineer , UN Habitat, Thatta• Fore man , KPT• General Secretary , PFF Badin• Rural Infrastructure Engineer, SCDP /
CDA, Badin
Shelter Response
Coverage Concentration in Accessible Area near Urban Settlements Limited Traditional Design optionLimited Transitional / Core Shelter Response to 2011, Flood
UNHabitat Design in Thatta
Hands Shelter design in Thatta
KPT Design in Thatta
SC Focal & UNOCHA resources and field observation concludes
Local Housing Typology & Practices
Local Materials & Behavior Material Source / Availability Behavior Environmental
ImpactStone
Blocks
Kotri, Hyderabad, Jamshoro
Urban areas
Durable
Vulnerable against salinity
Affecting the natural settings , with embodied energy utilized during transpiration
High effect because of Cement / Crush /Sand
Bricks Kilns working near river banks / canal banks to use saline free earth for bricks
Poor Against salinityChallenge to find Salt free bricks
Embodied energy during burning in kiln and transpiration
Babhur Timber
Devi
Locally available in Thatta & Badin abundantly
Stiff wood ,take long time to decayStiff but weak against pest / Termite
production cycle is 10-12 years , self growing because of seeds spread around
Takes long time to get mature
Lai cladding plants Thatta Kacha Area Hard sticks , long time to get decay and bear wind speed
Self growing plant , grooming in 1 year
Popular / Saveri KPK / Sukkur Poor against termite /pest Undefined yet
Sufeda Punjab / Local often Stiff to carry l.oad but poor against pest / termite
Undefined yet
Sand Jham Peer, Gharoo , Kotri Due to course quality does’nt give strong bond
Stone crushing Crushing impacts environment , impact to natural settings
Indigenous Practices
Construction Typology The house which is one room for a family is called as Kotha ,
Landhi, Chapra, Jhopra, Taike de Ja in Sindhi
Classification depending on foundation type A-Bundha Khor B- Tarh Dasu
“The house is called as Loh Kaath when steel nails are used to connect timber in framing, bracings and roofing rather tie up with rope. As “Loh means Steel and Kaath s for Timber in Sindhi language”
Posts standing on wall plate above masonry “ Tarh Dasu”
Posts provided directly into ground “ Bundha Khor”
Room Sizes Ranges between 16x12-24x12
Structural Overview:Foundation: “Charri” in local language”
Three types of practices observeda) Poles along with cladding provided deep in 2.5ft wide & 2.5-3ft
deep continuous excavation to hold the structure while poles spacing ranges between 6-8ft mostly in northern areas.
b) All the vertical Poles inserted into ground while poles spacing ranges between 1-4ft in the areas of heavy winds and cyclones towards sea.
c) Brick or stone mud mortar or CS mortar masonry with a heavy profile timber wall plate / Plinth beam provided on plinth level 1.5-2ft above ground level to carry the structure load through vertical posts resting on it. Such type of foundation is in old buildings but not observed in recent construction.
Walls: “Bhit in local language”
Walls of two types observed a) Heavy profile cross section posts spacing ranges between 6-8ft
filling with concentrated twigs to plaster and get thickness up to 1.5ft. This practice is observed in Tando Bago.
b) Relatively small cross section Posts spacing ranges between 1-4ft
filling with twigs in between to plaster and get thickness up to 6inches.
Indigenous Practices
Cladding: “ Banth in local language”There are different locally available twigs
are weaved together to be used as cladding.
a) Lai Twigs:b) Cotton twigs:c) Sunflower twigs:d) Timber irregular cut pieces or saw mill’s
waste: Horizontal Bracings: “ Patti in local
language” Horizontal bracings provided to vertically
align the cladding and tie the posts together internally and externally spacing ranges between 6” inches-1ft
Different types of wood is used in bracinga) Saveri:b) Babhur:c) Jar:d)Devi:
Indigenous Practices
Roofing: “ Chit in local language”• Two way slopes using timber profiles of
different size in Ridge, Purlin and Rafters resting on wall plate with two layers of “Kani or Pun” Thatch with a sandwich plastic sheet layer.
• Tie up thatch with structure using nails or rope “ Wanr”
Plastering: “ Laipa/ Raga in local
language” • Stabilized Plastering on cladding and
roof layer by layer normally three layers
Challenges
Challenges:
• Termite & Pest Attack deteriorates foundation poles causing major damage in flooding & Cyclones
• Excessive Salinity swallowing underground timber and erode plaster within few months
• Low Bearing capacity of Soil because of salinity / high water table during flooding
• Transportation / accessibility as material carriage costs 10-15 % of total cost
• Land Ownership
a) tanents (Hari) b) Land Lords barren lands resident c) “Pud” Resident d) Mallah on Coastal belts
• Carrying of Salt free Earth from canal beds (Silt) for Plaster by women mostly
• Conflicts
Indigenous Practices
Good Practices:
• Laying of Gross /shrubs over saline earth to resist Salinity to come up on floors
• Elevated stabilized Plinth Protection & Drain away
• Mud stabilization with Animal Dung and Husk
• Lime ,Jute Slush and sand mix final plaster
• Foundation Masonry with a heavy timber beam on top
• Tying up of roof Thatch with ropes or extra purlin on top
• Concentrated Bracing• Raised Platform• Not to plaster 1’ at bottom to avoid
plaster erosion• V Connections for corners and Flag Post• Polythene sheet wrapping to post stem• Proper Ventilation & Light
Indigenous Practices
Bad Practices:
• Connections / Overlapping & Joints
• Wall s Alignment / Plumb
• No brackets / Struts
• Load Transformation / Distribution
• Timber Quality Compromise
• No proper Compaction around vertical posts
• Large Room Sizes with week overlaps &
Connections
• Heavy Roofing
Indigenous Practices
Recommendations
• Community involvement from design to process with a strong Training component (On Job – Hands on)
• Demo Houses for internal staff / Artisans Orientations/ Capacity building before launching and segmental / Refresher orientations
• Maximum utilization of Community capacity & Involvement to create ownership feel for sustainability e.g Cladding , Plastering & Carriage
• Close Monitoring of process and construction through monitoring staffing other than supervisory and social staff.
• Local Purchase through purchasing from multiple hubs
Recommended Operational Strategy
Purchase Point
Purchase Point
Purchase Point
Purchase Point
Village 5
Village 6
Mid way Storage
Village 1
Village 2
Village 3
Village 4
Issuing Material to Community
Accountability through Monitoring Staff
“Tarh Dasu” is durable and resilient to Salinity, Cyclones and Flooding due to following characteristics
• Masonry Foundation• Timber detached from earth to get decayed • Plinth beam provides BOX behavior
Key Consideration:• Strong Base • Anchorage / Connections & Joints • Load transformation / Distribution • Water Proofing
Materials
• Babhur a stiff and durable locally available timber for structure framing and bracing as it takes more time to decay
• Lai Cladding • Stones best material to use in foundation masonry as its more resistant
against salinity • Lime sand mortar for masonry because of economy and low embodied
energy• Jute Slush to stabilize lime Mortar for Plastering final layer on roof top and
walls • I-Profile Girder as Ridge Beam
Design Recommendations
Foundation Plan Option: 1
Foundation Plan
Foundation Plan Option: 2
Foundation Plan
Foundation X-Section Opt:1
X-Section Foundation View
Joints / Anchorage / Connections
Ridge Anchorage
Roof Ties / Joints
Roofing Ties
Water Proofing
Water Proofing
(Traditional Housing – Weaknesses + Improvements ) = A strong , Durable , Safe and habitable local Design
Value of Money:
A strong house of life span 15-20 Years to avoid repeated repair / rebuilding time to time
Traditional House Costs: 900-1000 USD Cost = 1.5 x Traditional House Cost
Cost / Time Vs Quality
Time :5-6 Days with One Carpenter to erect framing and one mason day for masonry
Limitations:
• Main Timber Profile limited length in Babhur
• Stone Min supply of 650 cft / load , which can be a limitation for replication
Challenges