What is Earthbag Construction?
An Earthbag construction is an inexpensive natural building technique. It’s a method of creating structures which we can build very quickly, are very strong, and are able to withstand a host of natural occurrences such as flooding. Bullet and blast resistant earthbag constructions can even withstand tornadoes and earthquakes. Earthbag construction is one of the most innovative and sustainable architectural processes used today. It represents one of the strongest sustainable building systems known.
Additionally, they are wind, rain and fire resistant. Reinforced concrete is the only other thing stronger than an Earthbag building, which of course is not sustainable. Earthbag building is more sustainable than most conventional buildings because it minimises the use of energy-intensive industrial materials, and can create very energy-efficient building shells. It is also more economical to accomplish, and takes less skilled labour. Earthbag construction offers remarkable variability in building creation. Let your imagination run wild, add your creative edge to personalise your design.
What is Earthbag Construction like?
The method for building an earthbag home requires very basic materials for construction; strong sacks, filled with inorganic materials such as moist subsoil, sand and/or clay specifically. It is better not to use regular dirt because when you compact sand and clay and let it dry it makes a very hard substance. Standard earthbag building filling material has internal stability. Angular gravel or volcanic rocks (crushed) are examples of other materials that are being used to fill earthbags. Earthbag building uses polypropylene rice bags or feed bags filled with soil or insulation. We then stack them like regular masonry. By gradually laying the earthbags in courses similar to bricklaying, the walls of the structure are built up. Between each row there are two lines of barbed wire, which acts like velcro stopping the earthbags from slipping while adding tensile and lateral strength.
Once the barbed wire and earthbags are set it is virtually impossible to push/slide the earthbags off of the structure (except in very heavy rain while you are still building it – beware). When the structure is complete you then cover it with chicken wire. The final plastered walls resemble adobe structures. Earthbags walls can be curved or straight. However, curved walls provide good solid lateral stability.
Here’s a timelapse video from youtube on earthbag construction
How to Start Building an Earthbag Home?
The tools and materials necessary for building an Earthbag construction are:
Woven polypropylene bags (about 18” x 30”), bucket chute (4-gallon bucket with bottom cut off), 4 or 5 heavy duty 2-gallon cement buckets, stringline, metal chisel and scrap steel for cutting barbed wire (or bolt cutters), hammer, sheet metal slider (about 13” x 16”), 15 gauge galvanized wire, knife, wire cutters, tape measure, 4-point barbed wire, corner guide, grub hoe or grape hoe, level, tampers, bundle 500 bags, shovel.
The basic methods for the construction of an Earthbag structure begins by digging a trench 4 foot deep gravel foundation only for the walls. Add extra gravel to create a level base. Fill the first 3 layers of bags with D1 gravel for drainage. It is a good idea to add buttresses for support. These rocks are for holding down the 2 strands of 4-pronged barbed wire which will run between each earthbag layer. After placement, each layer is “tampered” by hand until solid.
How Can Earthbag Construction Benefit People?
Earthbag building methods have numerous advantages over traditional construction methods. Earthbag constructions are healthier, sturdier, and faster that traditional building methods. They also have tremendous potential for areas around the world which are prone to flooding, earthquakes and tsunamis.
Did you know that the average earthbag home can stay intact for well over a century? The wall materials themselves can be immune to moisture damage. They are naturally able to withstand great forces. An earthbag building in Haiti or Nepal for example could be the answer to re-homing those who have lost their homes due to the devastation of hurricanes, tornadoes and earthquakes. The speed and ease of build make them far more cost effective than conventional house building.
Have you built an earthbag construction? We’d love to hear from you if you have, or if you’re thinking of building one. Perhaps you’re looking for funding or partners? Consider joining the Save the Earth Cooperative to get an earthbag construction project off the ground!