Dear Amogh
There are other way for roof such as
1. you may go with RSS Joist, batten and stone slate roof.
2. Other option is Iron truss and AC Sheet roofing.
3.Iron truss and GI Sheet roofing.
Ferror -Cement is mixture of cement coarse sand reinforced with layers of woven steel mesh and closely spaced small dia steel bars. You can go ahead with this option also.