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=Cob: Characteristics & Benefits=

In Old English, //cob// was a root word that meant //lump// or //rounded mass//. Cob building has existed since before the 13th century and many cob houses still stand today after over 500 years (Wikipedia). Traditional materials include clay which binds the ingredients, sand to strengthen the mixture and straw to strengthen the walls once they are hardened (Daily Creek). Unlike adobe and straw bale construction, cob does not use bricks or blocks. Forming a cob house is similar to sculpting as the home is built from the ground up in any shape the builder desires. This creates flexibility as windows and entrances can be placed anywhere on the structure. A cob home may have sloping walls, arches and lots of wall niches. A dome shape also uses 60% less structural material than a traditional box home (PlanetGreenTV). Cob houses can even withstand rain and minor flooding, due to their porous nature, as long as the foundation and roof are strong. This can be achieved by layering cob over oak foundations. An even stronger option would be creating a rubble-filled trench on top of a perforated drain so that excess water naturally filters out. For a truly long-lasting cob house, finishes like plaster and stucco can be applied to the exterior walls. Earth plaster, which is a refined version of the cob using the same ingredients in a finer mill with the addition of plaster sand and/or flour paste can be applied and reapplied over time for protection without sacrificing the natural breathability of the home (low impact living initiative). Wide roof eaves also protect the walls from water damage. An important aspect to cob housing is their ability to withstand earthquakes. While they may not remain unharmed in every case, their dome-shaped walls carry much greater tensile strength than straight walls. If the structure fell apart, it would also be more likely to fall outward than inward, which could prevent the deaths of many people during a natural disaster. Also, the house benefits from its’ spherical design because the points of the structure distribute weight and handle stress evenly, unlike traditional box structures (rainforestinfo). Cob structures require additional heating in winter and remain cool and comfortable on hot summer days. As it is fireproof, cob can be used for building ovens, stoves and chimneys.

Since the materials are cheaply acquired (even free!) cob is an ideal building material in poor areas. It is however, a labour-intensive process, which can be beneficial in Haiti where homes are needed as well as jobs. Formal training is minimal and resources as well as workers can be found in abundance within the country already. For our solution, the substitution of clay for cow feces appears even more practical in Haiti. The feces serve as a binding ingredient, but also, allow for a material that would not require taking from the land, which already suffers from soil erosion. It also utilizes a resource the country has plenty of. Cob houses are bio-degradable, and all-natural. This is key in a country like Haiti where the eco-system is fragile from over-importing goods and soil erosion. Our solution would not upset the present environment. Cob also works well with other natural materials and therefore makes the homes customizable for the individual’s needs and tastes. Though our focus is on temporary shelters for families affected by the earthquake, it does not mean comfort is not an issue. For a family that must stay in a shelter like this for a long time, since re-building efforts can take years due to the severe damage incurred, we also considered the families themselves in our solution.

=Haiti: Facts and Climate=

** //[|Livestock in Haiti]:// **
 * **Cattle** || Sheep || Goats || Pigs || Poultry ||
 * ** 1,455,000 ** || 153,500 || 1,910,000 || 1,001,000 || 5,600,000 ||

<span style="background-color: #ffffff; color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 100%;"> Considering that cows poop an average of 128 lbs (58 kgs) a day. (from [])

<span style="font-family: Arial,Helvetica,sans-serif;">Climate in Haiti is tropical; semi-arid where mountains in east cut off trade winds (from [|CIA]). The best time to go is November-March, when day temperatures are in the 70s-80s F/23-32 C and nights are in the 60s-70s F/15-27 C. The rainy season is May-July, but even when it rains, it usually lasts for only an hour or two in the evening. Hurricane season is July-October. The hill country is always about 10 degrees F/5 C cooler. Evenings can be cool even colder in the mountain areas. (from @http://www.southtravels.com/america/haiti/weather.html )



=How to Build a Cob House with Manure:=



<span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">I am a strong adherent of cow manure. If you are squeamish, just get over it. Seriously. Manure has been used in plaster for eons – it is totally safe and beneficial, and yes, the smell //will// go away. Manure lends strength, durability, and texture to earthen plaster. The fibers make for great tensile strength, and I think that overall, manure helps make the plaster softer (at least to work with). <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Try to get manure from cows that are strictly grass-fed. I am a little leery of manure with grain in it, although that is what I had to resort to using in my interior plaster. I don’t think that it is a huge deal, but 100% grass-fed is what to aim for. Fill up some 5 gallon buckets and keep them covered to prevent the poop from drying out. After a day or two, the manure will ferment a bit and expand and become quite airy. That’s the best time to use it. ( [|Cob & Natural Building] ) <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"> <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;">media type="youtube" key="lS1vmfIRkkg" height="315" width="420" <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"> <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;">media type="youtube" key="DGz_ExY1wP4" height="315" width="560" <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"> <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"> <span style="background-color: #ffffff; font-family: Tahoma,sans-serif; font-size: 10pt;">Here is the video of the house made of Cow's pooh that was introduced in the Korean television show.

<span style="background-color: #ffffff; font-family: Tahoma,sans-serif; font-size: 10pt;">They find out that not only it is very cozy and strong, the house doesn't smell; and it contains the room temperature and the humidity on the adequate levels; and also it doesn't leak even in rainy weather. <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px; text-align: left;"> <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px;"><span style="background-color: #ffffff; color: #111111; font-family: Arial,Helvetica,sans-serif; font-size: 100%;">Building the huts seemed like a straightforward process. Dried cowpies are placed into stacks numbering into the hundreds. Wet poop is then molded around them. The poop is presumably mixed with a higher concentration of straw than normal, probably to function much like rebar would in cement. The exterior poop is spread thick and strong to keep the interior poop dry through the rains. It's doubtful that the houses can survive much more than a few weeks of rain, but that should be enough to keep the fuel flammable until the weather clears up enough to dry more cowpies. <span style="background-color: #ffffff; color: #111111; display: block; font-family: Georgia,'Times New Roman',Times,serif; font-size: 14px;"> <span style="background-color: #ffffff; color: #111111; font-family: Arial,Helvetica,sans-serif; font-size: 14px;"> Build time depends on how many people are involved in the construction process and the size. Unlike a typical house, building with cob is a much smoother process because there is no need for power tools and spackling. In dry weather, the cob wall can be finished within one day. Hence, cob houses can be the manifestations of the builder’s artistic skills. Often, a team of 5-6 people can construct a cob house of medium size in 6-8 weeks. media type="youtube" key="VJk_AFY4sgE" height="315" width="420"

Cob Recipe:
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">1. Mix mud/straw/sand mixture. The exact recipe is arbitrary but the consensus is that you start with clay soil, add water until it is mud-like, mix in sand, then add straw until the mixture holds together and is moldable. Depending on the clay content of your soil, start with two parts sand to one part clay soil. Add long pieces of straw to strengthen the mixture. Again, the exact amount of straw is arbitrary, but add enough so the mixture holds together.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">2. Make the cob blocks, loaves, or "globs." The mud mixture can be molded into bricks using any brick-shaped mold you purchase or make. Some cobb experts advocate making the mud mixture the consistency of bread dough. Then a large handful of mud is kneaded, just like bread, and formed into loaf-shaped bricks. These loaf-shaped bricks are then "globbed" or slapped on top of one another to form the walls. Still other cobb enthusiasts merely take handfuls, or "globs" of the mud mixture and slap them in place on the walls. Whichever method you choose, only mix enough of the mud mixture to apply a 6 inch course to the walls, which must then dry before continuing.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">3. Build the walls. The walls must be built slowly, over time. Only add about 6 inches to the height of the walls at a time, then allow it to dry completely. If you build the walls too high too fast, they will dry unevenly and crack. Use the cobb building-block method of your choice and stack the loaves, bricks or globs of cobb-mud mixture as though you were building a brick wall. Smooth the areas where the bricks come together using some of the cobb mud mixture so the wall looks like a solid mass. You shouldn't be able to distinguish individual cobb bricks, loaves or globs.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">4. Mix plaster coating. Once the walls are built to the desired height, a mud-based plaster is applied to both the interior and exterior surface. The plaster is made with similar materials to the cob mud, but it is smoother and thinner. Natural plaster contains sand, clay, short fibers--such as short chopped straw, cattail fluff or even fresh cow manure--and a binder such as wheat paste made from flour and water. Believe it or not, cow manure is the fiber of choice for many builders of cob houses. Once dried, plaster containing cow manure does not smell like manure. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Mix three 5-gallon buckets sifted sand, one 5-gallon bucket wet clay, three-fourths of a 5-gallon bucket cow manure about 8 cups of wheat paste, and enough fiber (chopped straw, cattail fluff or fresh cow manure) so you can see and feel the fiber particles in the mix.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">5. Apply the plaster. First, wet down the completed cobb wall (this helps the plaster adhere better). Don't soak the wall; merely wet down the surface. Then apply plaster either by hand or with a trowel. Apply a thin coat of plaster, something between ¼ to ½ inch. Smooth out the plaster until it is aesthetically pleasing. If the plaster is difficult to spread, add a little more water.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">6. Burnish surface of plaster. When the plaster has dried somewhat but not completely, burnish the surface with a piece of rubber or a wet piece of burlap. This will further smooth the surface and give it a finished look.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">7. Once the walls are built and plastered, install the doors and windows, and put on the roof.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">How to Build a Cobb House | eHow.com