MIPAA Mission Report – Part B projects/services
A&D, India
Aug, 2003
Micro concrete tiles for roofing (CART)
Part B1
Name of the project
Roof design solution for a private residence in Mysore
Type of project
Design and application of Micro Concrete tiles roofing
Location
Roopanagar colony, Mysore
Role played by the member
Design, consultancy and supervision
Reason for documentation
As expressed by CART
CART mainly works like a network. It has identified or created various resource people who can
construct with their technologies. While undertaking a project, it tries to put these people together
in the most effective way possible.
Thus without actually undertaking the responsibility of
implementing the project, they bring about a meaningful architectural solution.
As seen by the team
This project is a typical example of how CART works in partnership, sharing its resources, namely
technological know-how with other stakeholders who are involved in the actual activity of building.
About the project
Background
Most of the present day materials used in conventional building are energy intensive and
unsustainable. The techniques employed for constructing with them are also costly and
specialized. It therefore becomes necessary to employ cheap, local and less energy intensive
material to render building technology sustainable.
There are a many well-established alternative building techniques. However to make the use of
these techniques spread, the first step is to find acceptance among the people. It also becomes
imperative to be able to easily transfer the skills needed to construct with these technologies to
the local people at the field level. Also though being low cost, these technologies need not be at
conflict with aesthetics.
Moreover, these technologies should also have a potential to be
employment generating, apart form being energy conserving.
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A&D, India
MIPAA Mission Report – Part B projects/services
Aug, 2003
Project details
This bungalow is situated at Roopanagar, which is a middle and upper middle-class residential
colony and is located on the outskirts of the main central Mysore city.
Designed by Architect Mrs. Lalita Raj, it is a residence for an upper class client. The architect,
who also happens to be the wife of Mr. Ravi Kumar, approached CART for a roof solution using
Micro Concrete tiles.
With almost 12 years of efforts of CART and organisations like the Building Center and
individuals such as architects, engineers and sensitized entrepreneurs, the technology of MCR
tiles has found a good popularity. Many people, seeing built examples are now counting MCR as
an option for use. Presently CART is a Technical backup unit for micro concrete tile roof (MCR)
technology in the south Karnataka region, a technology being promoted in India by Development
Alternatives (DA)
The role played by CART was to give an appropriate roof design, which included working out the
shape, the load calculations, the design of the structural members and the quantity of tiles. They
recommended to the client a few tile manufacturers and dealers on the priority of quality. This is
another important role played by CART to encourage local entrepreneurs to manufacture
alternate materials, by promoting them to the clients who approach them. This also raises the
quality control level of the materials in the market due to the induced competition.
The design solution was to provide sloping roof on two levels, at the ground floor over the porch
and the entrance and on the first floor over the balcony and terrace. The tile color selected was
green to contrast the red of the compressed earth blocks masonry. A steel truss and purlin
understructure was selected.
After the designs were approved, CART provided supervision and management services to
ensure that the construction was carried out as per stipulated specifications and quality
standards. Due to its previous experiences in the construction of similar roof designs, CART has
been able to train a team of technicians who are able to erect roof structures using MCR tiles.
Hence, these technicians were employed for this project.
Completed only recently, this house stands as another example of CART’s endeavors to promote
alternate building technologies. In future after a few years another coat of paint will make the roof
look as good as new, and ready to last for a life time.
About the technology
Micro concrete tiles for roofing is one of the technologies alternatives developed by CART under
the Roofing Systems Habitat subprogram. MCR tiles compared to other slopping roof materials
such as G.I. sheets, Mangalore tiles, wooden shingles, slate and asbestos, are cost-effective and
thus offer more value for money; are highly durable; are lighter than other roofing tiles, thus
requiring less understructure; can be easily installed; can be colored; reduce the heat gain; do not
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MIPAA Mission Report – Part B projects/services
A&D, India
Aug, 2003
make noise during rains and do not contain asbestos fibers. Moreover, their production is eco
friendly, compared to other roofing systems.
MCR technology is a result of global research and development effort. The tiles are being
marketed extensively in Latin America, East and West Africa and South East Asia. Every year
over 40 million tiles are installed. MCR tiles are being marketed under different brand names such
us TARAcrete, Duracrete, Swisscrete, MYCON tiles in different region of the country by leading
product promoters.
MCR is highly profitable for micro and small-scale building material producer. A capital of about 3
lakh yields up to 40% profits in the first year of operations. It can be easily adapted to both urban
and rural markets.
It can be installed on both steel and wooden understructure. A variety of roof designs for farm
and country houses, bungalows, verandahs and pavilions are possible with MCR tiles. They have
also been used on industrial sheds, workshops and restaurant. It can be used to build any form
of roof like lean to, gable, hipped, Industrial sheds and many more. It can also be used for
cladding on sloped RCC roofs. It can be painted with any color. Special tiles for roof features like
ridge tiles, sky light tiles, smoke tiles are available.
Technical Specifications
Clear length of the tile: 500 mm
Length after overlap:
400 mm
Clear width of tile:
240 mm
Width of overlap:
200 mm
Thickness:
10 mm
Weight/tile:
2.80 KGS
Load bearing capacity: 80 KGS
Tiles required for 1 msq.
12.5
The moulding process of a micro-concrete roofing tile
Production process
MCR tiles are produced by vibrating an optimum mix of cement, sand, aggregate and water on a
vibrating table for about 45 seconds. The spread mixture is then transferred to a High Impact
Polystyrene mould and aligned where it gets the required shape. After curing for 24 hours in the
mould, the tiles are immersed in a curing tank for a minimum of 7 days after which they are
sprinkle cured for 14 days. Then they are ready to use.
The equipment is supplied by TARA, a leading sustainable technology marketing organization.
To make 12000 tiles per month, 160 cement bags, 10 cu.m of sand and 5 cu.m of aggregate are
required along with two skilled stuff and five workers.
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A&D, India
MIPAA Mission Report – Part B projects/services
Aug, 2003
Building with MCR Tiles
MCR roofs are constructed in a conventional manner using rafters and purlins made from wood
or steel. Rafters are according to the shape and size of the roof. The purlins are welded at a
distance of 40 cm from each other.
MCR tiles are secured by tying them to purlins with G.I wire. The angle of roof slope should be at
least 22’. Greater inclination of up to 30’ is preferred for more aesthetic appeal and high rainfall
area.
Standard architectural details for gable and hipped roof ridges, eaves, side over-hangs and
valleys can be used for MCR roofs.
MCR tiles are also excellent cladding materials for sloping RCC slabs. They act as an effective
damp proofing layer and enhance the aesthetic appeal of the buildings. The tiles can be fixed to
the slabs with cement mortar.
Impact
This is proving to be an effective alternative to burnt clay tiles. Apart from economy it is also
promoting local production and employment.
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