After our first building experiment (in the previous post), Earth Bags appealed to us greatly for DIY projects for these reasons -- very economical, no curing, not much industrial material, very low energy footprint. So, in May
2015 we constructed a pedestal for a water tank using earth bags. This
is probably the cheapest construction option. We had one hired helper (Subramani Anna) and three
volunteers work for two days to raise it to 5' height. We used the soil we had
excavated earlier while digging a pond. We had established the right mix for
this soil before starting the project.
As the first step, we dug out a circular trench of approximately 1' depth and 5' diameter and filled it with
two courses of gravel bags. We probably laid one course of gravel bags above the ground level.
After every course was laid, it was tamped very well both from
the top and outside. After achieving (both horizontal and vertical) level, we laid two barbed wire strands and
placed bricks on them. We found it easy to cut out the strands in advance before laying them. The loose end of the barbed wire roll was left
dangling by placing it as shown below:
Only when we reached a height of about 4’ did we realize
that we needed to have filled the hole in the middle! It was difficult to get
in there and tamp the bags. When we built our second pedestal, we filled the
center the same time we did a course. The center part was not 100% filled, we
basically placed two or three small bags.
Anna (in the picture above) plugged all the holes in between the bags.
Having a smooth structure was necessary to ensure that we used less cement for plastering. The next day we wrapped this structure with chicken wire and
plastered with a cement mix. The total construction cost of this was around Rs.
2500. This
is probably the cheapest construction option.
Two years later, this is how it looks:
The blue water tank at the back is sitting on top of the cement stucco Earth Bag base. We now have neem, bananas and tasty papayas growing around this water tank.
-- Hema
