CORE shelter design recommendations for coastal areas of sindh pakistan
Engr.Zubair Hashmi’s study as consultant Field Research 17th- 29th May,2012Recommendations for Permanent Shelter in Coastal Districts of Lower Sindh 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 SurveyCoordination • Coordination Officer ,UN OCHA • Logistic Officer, Tear Fund • DDMA Representative, Badin • Technical Lead, IOM Hyderabad • Shelter Cluster District Badin Focal • Chief Engineer , UN Habitat, Thatta • Operations Officer .Hands Organization • Fore man , KPT • Site Supervisor , HF • General Secretary , PFF Badin • Provincial Coordinator, IDC • Rural Infrastructure Engineer, SCDP / CDA, Badin
Shelter ResponseUNHabitat Design in Thatta Coverage Concentration in Accessible Area near Urban Settlements Limited Traditional Design option Limited Transitional / Core Shelter Response to 2011, Flood SC Focal & UNOCHA resources and field observation concludesKPT Design in ThattaHands Shelter design in Thatta
Local Materials & BehaviorMaterial Source / Availability Behavior Environmental ImpactStone Kotri, Hyderabad, Jamshoro Durable Affecting the natural settings , with embodied energy utilized during transpirationBlocks Urban areas Vulnerable against salinity High effect because of Cement / Crush /SandBricks Kilns working near river banks / Poor Against salinity Embodied energy during burning canal banks to use saline free earth Challenge to find Salt free bricks in kiln and transpiration for bricksBabhur Timber Stiff wood ,take long time to decay production cycle is 10-12 years , Locally available in Thatta & Stiff but weak against pest / self growing because of seeds Badin abundantly Termite spread aroundDevi Takes long time to get matureLai cladding plants Thatta Kacha Area Hard sticks , long time to get decay Self growing plant , grooming in 1 and bear wind speed yearPopular / Saveri KPK / Sukkur Poor against termite /pest Undefined yetSufeda Punjab / Local often Stiff to carry l.oad but poor against Undefined yet pest / termiteSand Jham Peer, Gharoo , Kotri Due to course quality does’nt give Stone crushing Crushing impacts strong bond 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 “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” Classification depending on foundation type A-Bundha Khor B- Tarh Dasu Posts standing on wall plate above masonry “ Tarh Dasu” Posts provided directly into ground “ Bundha Khor” Room Sizes Ranges between 16x12-24x12
Indigenous Practices Structural Overview: Foundation: “Charri” in local language” Three types of practices observed a) 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 bracing a) Saveri: b) Babhur: c) Jar: d)Devi:
Challenges 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
Indigenous Practices 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
Recommended Operational Strategy • 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 Village 1 Purchase Village 2 Point Purchase Issuing Material to Community Village 3 Point Mid way Purchase Storage Village 4 Point Purchase Village 5 Point Village 6 Accountability through Monitoring Staff
Design Recommendations“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 behaviorKey Consideration:• Strong Base• Anchorage / Connections & Joints• Load transformation / Distribution• Water ProofingMaterials• 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
Cost / Time Vs Quality Time : 5-6 Days with One Carpenter to erect framing and one mason day for masonry (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
Challenges Limitations: • Main Timber Profile limited length in Babhur • Stone Min supply of 650 cft / load , which can be a limitation for replication
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