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[[Image:Storage_tank_for_rooftop_harvesting_icon.png|right|100px|]]
[[Image:FerrocementTank.jpg|thumb|right|350px200px|Conclusion of Acul des Pins Ferro-Cement Tank Project – Haiti. Photo: [http://watercharity.org/node/253 Water Charity.]]]
Ferrocement water tanks are made of steel mesh and wire, covered on the inside and outside with a thin layer of cement-and-sand mortar. The walls may be as thin as 2.5 cm. The tanks can be used for individual households or for whole communities, and they provide a relatively inexpensive and easy-to-maintain storage method. To avoid bending forces in the material, most ferrocement tanks have curved walls, in the form of a cylinder, a globe or an egg. Compared to concrete reservoirs, ferrocement tanks are relatively light and flexible. <br>
To protect the water from contamination, the tank is covered with a lid or a roof that can be made of various materials, but is usually ferrocement. In this case, an aeration pipe with a screen is needed to allow fresh air to circulate in the tank, while keeping out rodents and insects. A manhole in the roof gives access to the tank for cleaning and repairs. Water flows into the reservoir through an inlet pipe, which is normally above the water level.<br>
'''Specific advice''':
[[Image:FerrocementTankDiagram.JPG|thumb|right|300px200px|Ferrocement tank components.]]
Range of volume: From 1 m3 to over 80 m3.
Range of depth: Usually, between 1.5–3.0 m.
====Build the roof of the tank====
[[Image:PaintedTank.jpg|thumb|right|300px200px| Freshly painted tank to match the colors of the Nicaraguan flag. Photo: [http://waterforwaslala.wordpress.com/2011/08/08/ferrocement-the-coolest-invention-since-the-smart-phone/ Water for Waslala's Blog.]]]
# Cut the wood boards so that one edge is curved outward. This can be done while the tank walls are curing. The tank size will dictate the necessary sizes of the forms.
# Once the walls are fully cured, position the wood beams inside the tank. One log will be the center pole sticking up vertically from the center of the foundation. Two logs will be cross bars near to the top of the walls to support the wooden roof forms. Additional vertical logs will also be used to support the wooden roof forms; these logs should be placed along the inside circumference of the walls.