Roof is one of the important and appearance part of the houses and other
buildings. In Sri Lanka, the most common roofing materials use are clay tiles,
asbestos sheets and cement tiles. Earlier days most of the roof built by clay
roof tiles, but nowadays roof are built by asbestos sheets and cement tiles
even though those are not better than clay tiles, because it has some
properties better than other material such as good thermal insulation, high
fire resistance, long lifespan, UV-resistance, durable colour and good
Roughly the roof
cost will be 10-15% of the total cost, thus peoples most use asbestos sheets.
Because low cost, high roof covering, quick construction and good strength, but
recently asbestos sheet has some health risk, so it is banned by government.
World Health Organization has said that all type of asbestos sheet cause lung
cancer, mesothelioma, cancer of the larynx and ovary, and asbestosis. But
asbestos is a cheaper than other roofing materials and also can be constructed
quickly, no need to more timber bars, no more labors and it has good strength
better than clay roof tiles.
At present, peoples
who willing to use metal roofing sheet as roofing material, because peoples
mostly like material as economically. But that roofing material has low thermal
insulation, low thermal resistance and less lifespan. Thus it is not more
suitable for roof of house. And available of clay not everywhere in Sri Lanka.
So we have to find other method to roof material with friendly of environment
In Sri Lanka, there
is no good roof material as well economically and friendly of environment.
Usually clay roof tiles are costly and other roof materials have some problem,
such as asbestos sheet has some health risk (lung cancer, mesothelioma, cancer
of the larynx and ovary), low thermal insulation, low thermal resistance and high
water absorption, and metal roofing sheet has low thermal insulation, low
thermal resistance, less lifespan and we have to use sub materials with these
materials (cooling sheet, secondary sheet). Available of clay not more in Sri
Lanka. So we have to find suitable soil to extraction. Also that clay should
has suitable chemical properties, physical properties and good strength.
Here clay take from
extract the soil, so we have to find a method for extraction. There are some
soil washing machine for separation the soil particles. But it is not more
suitable for extract clay from soil. So we have to modify the machine. We have
to collect suitable soil through the experimental. If that clay has not have suitable
properties, we have to change properties of that clay.
Significance of the
In Sri Lanka, the most
common roofing materials use are clay tiles, asbestos sheets and cement tiles.
But cement tiles is more costly and asbestos sheet has some health risk. At
present, asbestos sheet has banned by government. Usually clay tile is costly
material to build roof construction and usually clay is somewhere in Sri Lanka.
So we have to find method to as roofing material.
Scope of the study
Find the suitable clay for manufacture of clay
roof tiles according SLS specification of clay roof tiles. Finally, the product
should be economical as well.