asistance with design build of a clinic shade in DRC Africa
I am tasked with building the site for a new 1st line clinic in rural Kabare District of Sud Kivu. The clinic is contained within a 40ft container which sits upon a concrete slab. The container is oriented on a North-South Axis. The waiting area for the clinic is to the west of the clinic with a space of approximately 4.3 meters to a 2 meter high wall that demarks the edge of the road. I want to design a tension fabric structure to cantilever over the waiting area, protect the roof of the container (and the 500 ltr water tank on the roof), and shade the windows on the east side of the container from the pre-noon sun.
Our container is a typical 8 foot wide, 9' 5" tall and 40 ft long. Prevailing winds for the site are East to West.
Posted on behalf of Matt Spector by Pauline at REDR
Can we get a little more information ?
a.) what are the details of the wall at the boundary / waiting area ... can it be load bearing ? b.) could the wall be strengthened (say with retro added pilaster columns, and a top bond beam which will also increase head height / clearance c.) can you then consider a lightweight truss frame secured either side of the container, with overhanging eaves, and spanning to the wall, possibly landing on the pilaster columns / top bond beam. d.) the water tank can presumably sit (depending on height) between the truss frames e.) Stretching fabric across batons between the truss frames with diagonal bracing between truss frames will give quite a resilient structure, shae and an air gap above the roof with air circulation through the truss frames.
We used a similar process for site containers in Cambodia to lower the temperature and create covered workshop space adjacent to and between container offices. We put a plastic layer under the fabric (which was left over safety mesh) so the roof would not leak and drip during the monsoon. The plastic makes it potentially very hot, though longitudinal airflow through the trusses alleviates this as a fairly cheap and robust solution .
Kind regards .... Chris N
I have lived in Africa for at least half of my life, and I have seen local people producing excellent roofed structures.
If this was me doing this I would go to the local villagers and ask them to help in building a shade roof using local materials and know how. If you can use thatch it will be cooler than any modern materials, and the villagers will be able to maintain it for years to come. If this container is be there for some considerable time I would plant a few local trees (fast growing) around it as well.
The picture here although with other emphases looks sort of like what you are describing: http://blog.predatorbdu.com/2011/08/natick-brings-solar-shade-brings-juice.html This idea is a bit extreme! http://homeinabox.blogspot.co.uk/2012/05/container-solutions-india-bangalore.html Nice picture of a thatched roof over a container (near the bottom of the page) here: http://www.tiffanystravels.co.uk/blog/east-coast-rr
However, I would say a local design with some guidance from your side is likely to be the best all-round solution. I would try to avoid having one big structure due to occasional very strong winds in that area - better to lose part of the shade system than all of it. If you can make both the Eastern side window shade/canopy and Western side waiting area shade separate from the over-container shade then you should get less overall damage in strong winds.
Having a double skinned with interstitial airflow approach always help reduce the temperatures but well maintained single layer thatching is very good all round. In S Kivu there may be a tradition of making roofing tiles? There is in Rwanda (even if much reduced by the 'ban' on cutting down trees). These provide a heavyweight option that is quieter in the rain than cgi sheeting but you always get some leakage/drips which if mud is used to bed the tiles can be a bit mucky. I like James's approach - get the local people involved, have a couple of sessions with them and bash some ideas into shape.
All the best with this.
This thread is public, all members of KnowledgePoint can read this page.