Ferro-cement was invented around 1840 in France. Ferro-cement structures are created by constructing a frame from thin steel rods (rebar) that is then covered in a metal mesh to create the form of the structure. Then thin layers of sand and cement are plastered over, resulting in a hard, strong finish, ideal for a water tank. Nearly all land-based projects have a need for water storage in tanks and ferro-cement offers a long term pragmatic solution.
The tanks that I built are used for drinking water, harvested from the metal roof of a house located next to the tank. For catching drinking water use metal or tiled roofs and avoid thatch or wooden shingles. When the tank is finished the roof should be cleaned and a first flush system installed. This redirects the first part of the water coming out of the gutter away from the tank so any debris or leaves do not go to the tank (more about that in the designers manual).
It is a good idea to position the tank in a place that is shaded and easy to access. To maximise your harvest you can calculate the square meters of your roof and average rain fall in your area. There are several online calculators which make this easy. Then you will know the volume of the tank you can build. The tanks I built (shown in the photos) are 3000 liters and were built in workshops. If you build a tank of 1000 liters, it is still light enough to make it portable.
Matt Prosser 29.05.2017