Ms.UBIEDENDIECK of VRO appreciates to good work done by women in SEVAI centre in Ferro cement prefabricated roof and toilet panels.
The main objective of SEVAI -SRC is to identify, orient, motivate, train and assist the rural women self help group members to take self employment venture as an alternative career. The SRC provides training in Ferro-cement around for a long time; it can help contain construction costs, Sakthivel, Dr.K.Govindaraju, Chairman of South Zone Board of Continuing Education.. The trainees are mostly middle school educated unemployed young in the age group of 18-35 years,. Training is conducted by experienced professionals. A roof with chicken mesh, prefabricated walls is `assembled' on the spot to put up a house. Impossible, house hold toilets it may seem. Can construction be so simple, these are possible, thanks to the increasing popularity of ferro-cement, or construction based on the ferro-cement concept. The idea of using cement mortar reinforced with wire mesh for various purposes has been around for some time. Its durability and serviceability, coupled with the low production costs, has made ferro-cement a favourite of architects and engineers concerned with low-cost housing. However, the versatility of the material that allows itself to be moulded into any shape has endeared ferro-cement to more people these days. "You can go in for any shape," says Dr.K.Govindaraju, who prefers this material for the roofs of his famed mud houses. Ferro-cement is nothing but a thin slab of cement mortar reinforced with wire mesh, which provides the reinforcement needed for the strength of the structure. The use of ferro-cement dates back to the 19th Century, when the Frenchman Joseph Louis Lambot discovered the combination of cement mortar and wire mesh for constructing rowing boats, pots, seats and other items.
15 Years old ferro-cement school building constructed by SEVAI-SRC in Keerikalmedu
The aim was to find an alternative to timber, which was usually damaged easily by water or dampness. However, from making boats, ferro-cement soon graduated into a material suitable for roofing and also found a wide variety of applications in the marine sector, agriculture, water supply and sanitation as well as in the energy sector. It was found suitable for making storage bins and for lining irrigation canals, constructing water tanks, septic tanks, sewerages and latrines. The versatile use was in housing sector that ferro-cement has found its most versatile uses. In Tamilnadu, SEVAI and its SRC started using ferro-cement for construction purposes;. It was also widely used for making water tanks, mainly due to the low production costs and high durability. Ferro-cement an `appropriate building technology,' or as a building process that was appropriate to the `climate, socio-economic conditions and natural resources of an area.' Though ferro-cement makes use of cement and steel, it is considered somewhat `sustainable' because of the cost-effectiveness of construction. In SRC, ferro-cement is used for constructing roof channels, doors, water tanks, latrines, slabs and biogas plants.
The channels are the basic components that are used for roofing with ferro-cement. The semi-circle channels are moulded using a brick mould over which layers of cement mortar and wire mesh are applied. The cured channels are easily transportable and cost-effective in construction. Construction using chicken mesh and cement has been in existence for a long time, especially in the West. But only that it was just described as such and not `ferro-cement,' as it is now. However, the difference between the two is in the quantity of chicken mesh used. In the olden type of construction, only one layer of chicken wire mesh was used. This was enough for just holding the cement to the side of the wall. But, in the modern technique, two to five layers of a mesh of chicken wire are used, depending on the purpose of the panels and the required strength. The discovery of reinforced cement concrete (RCC) had brought ferro-cement back to popularity during the early decades of the 20th Century. But, later, especially in the second half of last century, it began to be more popular. However, the ferro-cement roofs, because of their thinness, requires additional thermal insulation, Dr.K.Govindaraju says. "The roof has to be leak-proofed, after which a layer of tiles can be laid," he says. This will be enough to give the necessary insulation from the severest of rain and sun. Dr.K.Govindaraju points out; it uses only half the natural resources needed for ordinary RC construction. If designed carefully, most of the structural system can be used later. It is also possible to repair any portion of the structure as and when necessary. Another interesting use of ferro-cement in many countries is for reinforcing the existing masonry structures against the stress caused by external factors, such as earthquakes. This is done by encasing the existing masonry or plain concrete structure in a layer of ferro-cement. Apart from roofs and walls, ferro-cement is used for foundations too. On the level of design, it is possible to `sculpt' a house with ferro-cement. It is also suitable for low-cost housing through mass production of ferro-cement panels. However, this highly versatile material also has its disadvantages. Highly skilled craftsmanship is a prerequisite for ferro-cement construction, in the absence of which the structure can develop flaws and start leaking, in case of roof or water tanks. Though the channels can be transported from one location to another, the comparatively higher weight of ferro-cement products makes production on site necessary. However, the actual construction of such complicated structures needs painstakingly precise calculations and accuracy. SRC facilitates loans for candidates, so that they are able to set up their own enterprises. EtNS.