Ferro cement Roofing Technology promoted in SEVAI Rural Technology centre

Ferro cement roofing in RTC of SEVAI

 The Ferro cement technology package for roofing developed by SEVAI uses state-of-the-art design principles to manufacture reinforced shells, commonly called channels. They are produced on specially designed vibrating tables and profiled moulds. The production system is uniquely tailored to provide special end details, consistent shape and thickness; all crucial for high performance. The channels made with an optimised proportion of cement, sand and water, have a very high density, are impervious to penetration of water and provide high structural strength. Ferro cement roofing channels produced on mechanised equipment can be used for intermediate floor applications as well. Ferrocement roofing technology offers a viable alternative to conventional flat roofing systems such as reinforced cement concrete, reinforced brick cement, sand stone, etc. in both rural and urban areas of the country.Ferrocement roofing channels have a uniform segmental profile; they are 2.5 cm thick and 83 cm. wide. Maximum length of mechanically produced channels can be 6 metres. Longer spans for roofing can be built with intermediate supports.Ferrocement roofing channels are manufactured using a fixed proportion of cement, sand and water to give high strength mortar that is reinforced with a layer of galvanised iron chicken wire mesh of 22 gauge and Tor steel bars of 8-12 mm diameter provided in the bottom nibs of the channel.Ferrocement roofing channels can be safely transported after a curing period of 14 days. The Unique Features of Ferro cement Roofing Channels are Speedy installation; no shuttering required,30% cost saving over RCC roofing, Lower dead load on the walls, Usable as an intermediate floor, High strength to weight ratio, Elegant profile and uniform sizes, Large spans possible with intermediate supports. Ferro cement roofing channels are prefabricated elements. The mechanised system of production uses a vibrating table and profiled steel shell moulds. The production yard consists of a vibrating table positioned under a gantry system 6.5mts. in width. The gantry is fitted with a chain and a pulley system for ease of handling of shell moulds. A production team consisting of 2 masons, 6 semi-skilled workers and a supervisor can produce up to 5 channels of 4.6 mts. length each in 8 hours operation. The shell moulds are lifted with the cast channels in the green state. After 24 hours, the roofing channels are demoulded by using a specially designed mould lifting frame and demoulding tongs. The mechanised system does not require high skills but ensures high quality. Whereas, manual method needs highly trained masons and stringent quality control measures.Ferrocement roofing channels are simply placed in a series, next to each other, resting on opposite walls of a structure. The valley between channels is then filled with a plain cement concrete, over which a layer of bitumen is spread to ensure water tightness. A lean concrete of 2.5 cm thickness or mud phuska with brick tiles can be laid to make a flat surface and provide thermal insulation. Ferro cement roofing channels, offer unmatched speed of construction and can be used for: Residences, Primary schools, and other community buildings, Porticos, verandahs and garages, Industrial sheds, workshops and godowns and Farm houses and semi-covered structures. Govin