Case Study

Earthbag constructions are becoming populor in many places of the world. This is mostly because of environmental issues such as climate change, shortage of resources and alternative construction for those places being damaged by disasters like tsunamis. Also, economical issues can be the reason for using Earthbags.

When researching about use of Earthbag constructions around the world, I have came across with an article called "Earthbag Building in the Humid Tropics; Simple Structures", this blog will be an introduction of it. 

Overall summary of general principles;

1. Light materials are effective for cooling the building. 

2. Use as little metal and timber as possible to stay away from rust and termites.

3. Make sure to waterproof base course no less than 600mm high.

4. Consider rainwater flow on walls and have slopes.

5. Wide roof overhangs are needed to avoid strong sunlight.

6. Test materials for exterior rendering.

Soil Test

As for soil tests, there are 2 types that is need to be considered, the (soil) ball test and the bag test.

Ball test is to see the hardness of the soil by dropping 40mm size balls from 1500mm height. Depending on the results, there are several ways of use for the soil.

Bag test is to see if the bags will have any cracks or shrinkage or not after being filled.

Layouts for non-hazardous areas

There are many options for plan layouts to fit the area. But Earthbags being not stable enough to tolerate hazardous such as hurricanes, tsunamis or earthquakes, it is only suitable for non-hazardous areas. The following is the examples of layouts.

• Square outside corners / Piers at outside corners - the corner will help the structure stand for buildings without steel reinforcement.
  
  
  
  
  

• Straight walls - piers are needed for this layout.
  
  
• Circles - strong structure within 5m radius.
• Corrugated walls - straight walls coming in and out every 4m to work as support without piers.
  
  
  
  

Exterior Finishes
Wall must be protected from rain which cause erosion. Clay based material works well including lime, ash, and animal products. Oil mixture is used often as well. If possible, getting local product for free or low cost would be ideal.

Cement stucco is not recomended due to its charactaristics of absorbing water but emitting water very slowly.