Concrete Roof Tiles, puzolanic cement, earth houses, ecomaterials: EcoSur

In this third contribution in our series discussing Different experiences in reconstruction projects, the EcoSur E-magazine documents a project proposal for rapid action after a disaster.

Always after earthquakes, hurricanes, landslides, wars and other catastrophes, fast action is needed to create shelter, the same scenarios each time. Usually the limited existing financial resources are used to import tents, plastic and other non-durable materials. The population then builds sheds that protect from rain but do not provide any kind of security for the inhabitants and much less for their goods. Such provisional structures, that in reality have cost more than their worth, tend to become permanent...

From catastrophe to development?
Meanwhile, intern agencies and local governments profess that they want to take “advantage” of the emergency to bring real development to the affected zone…..organizing local workshops on material production and promoting self construction with local resources.  However, actual experiences reveal that rarely can these intentions be achieved because establishing local productions takes time and dedication. To buy concrete blocks from large manufacturers and import zinc sheets for the roofs seems more convenient. Additionally, many “rapid solutions” (and expensive) are being offered in the international market, from plasticized cardboard houses to the famous sandwich panels with Styrofoam and plastered mesh on both sides.

Strategic reserves
It’s evident that these parameters have to be changed in order to reach real solutions. Strategic reserves have to be established to be able to act in a rapid manner in emergency situations. EcoSur partner SofoNic has developed a system of lightweight ferro-cement panels that permit rapid assembly of an emergency module. They are managed by hand with ease and result in a module of a progressive house. Let’s draw a case that could be real:

SofoNic has its workshop to produce the panels and beams. This machinery is mobile and could be transferred to another place instantly, the only requirement on site is a roof and electric energy. SofoNic has a quantity of panels and beams in stock, enough to build 30 modules of 3x3 meters. As the panels, beams and roofing tiles are made of concrete; they can be stored without problem in even inclement conditions. In the case of a hurricane, an inundation or some other situation that needs rapid intervention, immediately the panels and roofing materials for three houses can be loaded onto a truck and, together with three qualified masons, the journey to the action area can begin. By organizing self-builders these three secure modules with the respective foundation, walls, floor and roof can be built in three days. If the conditions are ready, another truck arrives with the machinery to begin the production on site, from which point on three modules a day can be assembled...

The affected population can move into their small but secure module, can place a lock on the door and don’t have to fear thieves (this is a principal preoccupation of people living in provisional shelters). Little by little the small modules convert into houses…..the program is conceived so that rooms can be added. These additions can be with the same panels or another material. Here one could achieve a local small business...

And the cost?
The lightweight ferro-cement panel costs approximately the same as concrete blocks or bricks, but its fast assembly and good finishings (just waiting to be painted) make this construction economically attractive. SofoNic also builds commercially with this system.  CIDEM in Cuba, together with COSUDE (Swiss development agency), have agreed to use this technology in its post-hurricane reconstruction projects. Together with the involved municipalities they have the idea of responding to the current emergency, but in the near future want to build up a stock of emergency panels in each municipality to be able to act fast. The German NGO “SODI” has decided to support this same concept.

What is ferro-cement?
A technology that combines the best of cement with the best of steel... the result of which is little cement, little sand and little steel for slim and strong elements of reinforced microconcrete. It’s a technology that has been used all over the world, especially for large curved roofs as in the railway station of Milan. Dr. Hugo Wainshtok from Cuba is the expert in Latin America; he invented this system of panels more than twenty years ago, after the experience of having built the whole Cuban fishing fleet with this technology. Our colleague Wainshtok, friend of the EcoSur network, gives conferences and post degree courses about ferro-cement in many universities throughout Latin America.