Transcript Envirobeat Teacher’s Conference

Earth Bagging
Laurence Tockuss
Earthbag Building: An Introduction
Building with earthbags is both old and new. Sandbags have long been
used, particularly by the military, for creating barriers or for flood
control. These same reasons also make them useful for housing. Since
the walls are so substantial, they can resist severe weather, floods,
earthquakes, and even bullets. They can be erected simply and quickly at
little cost, with readily available components.
The military have been building bullet and blast resistant structures with
sandbags for about a century. Lately, homeowners and professional
builders have constructed homes, clinics, schools, orphanages, shops
and other structures this way.
Earthbag building fills a unique niche in the quest for sustainable
architecture. The bags can be filled with local, natural materials,
lowering the embodied energy associated with manufacture and
transportation of building materials.
Earthbag Building: Advantages
Fill material is generally mineral composition and not subject to decomposition,
not attractive to vermin, nor flammable. The fill will not off-gas noxious fumes
into the building. Earthbag buildings are safe, quiet, rodent proof, and fire,
hurricane and flood resistant.
Earthbags are very adaptable and so you can build almost any style or shape of
building imaginable: domes, vaults, structures with vertical walls, curved
'organic' designs, roundhouses, you name it. In addition, you can build planters,
benches, privacy and retaining walls, to name but a few.
The ease and simplicity of building with earthbags should also be mentioned.
There is potential for unskilled labor to be tapped for implementing this
technology. One person familiar with the basics of earthbag building can easily
train others to assist in the erection of a building. This not only makes the
process more affordable, but also more feasible in remote areas where many
common building skills are not to be found. As one of the simplest, lowest cost
building systems in the world, using very few tools and almost no special skills,
it boils down to filling bags with soil or gravel and tamping the bags solid. What
could be simpler?
Sustainability
Earthbags have the advantage of providing thermal mass (when
filled with soil) or insulation (when filled with lighter materials such
as crushed volcanic stone, perlite, vermiculite or rice hulls). Bags can
act as a natural non-wicking, insulated foundation when filled with
gravel. They can be adapted for any climate simply by changing the
fill material in the bag.
Because earthbags can be stacked in a variety of shapes, including
domes, they can virtually eliminate the need for common tensile
materials in the structure, especially the wood and steel often used
for roofs. This not only saves more energy, but also helps preserve
forests, which are increasingly necessary for sequestering carbon.
Another aspect of sustainability is found in the economy of this
method. The fill material is literally "dirt cheap," especially if on-site
soil is used. Polypropylene bags have superior strength and
durability, as long as they are not exposed to too much sunlight. For
permanent housing, bags should be covered with plaster for
protection, but this can also be earthen and not particularly costly.
Earthbagging continued
Because polypropylene bags are designed for flood control and not
affected by moisture, you can build underground structures such as
earth-sheltered homes, storm cellars and rootcellars.
The list of advantages goes on and on. Do yourself a favor and look
into how you can benefit from earthbag building. You can save
money, do less harm to the environment and have a more durable
structure.
Earthbagging Instructions
Once you have decided on a structure you want to build:
1. Take a length of polypropylene sausage (use smaller lengths to start with).
2. Sleeve with a bucket with bottom cut out.
3. Concertina one end and fold under the bagging.
4. Put 4-6 small buckets full into the bag , while holding the concertina end of the bag ,lift and
drop on the ground a number of times to compact the contents to a tight tidy end
5. Fill with a mixture of dampened soil and/or sand (This is done by using small 2-3 litre buckets
(which anybody can handle)
6. Move backwards along the desired shape you wish to construct, while continuously filling the
tube and taking the weight of the soil fill on your shin to ensure a full bag.
7. When the end of the open bag is near, fold the remaining bag under and tamp (pack down
tightly with a succession of blows or taps) the end flat to complete the run, or to provide a
flat end to continue your run.
8. When the first layer is complete, tamp again. Tamping solidifies the structure and remove any
excess space in bag.
Earthbagging Instructions continued
9. Fix barbed wire to the tamped surface, this will
hold the next layer in place and provide structural
strength
10. Tie wire can be affixed to act as an anchor for
render wire , fixed at about 1-1.5 meter lengths
11. Lay next course
The fill mix will be determined by the desired
outcome and available soil mix. If additives are
used in the mix and combinations are outcome
dependent, you may need a mixer. For example,
concrete/ lime /magnesium oxides can be added
to the mix for waterproofing.
Enjoy the process, and remember this type of
building is very forgiving and can be constructed
and enjoyed by all ages (3-77 years). If you make a
misalignment simply push it back into shape!