supply of single skin colour coated profile roof sheet , supply of single skin colour coated profile roof sheet , supply of single skin colour coated profile roof sheets of 1015 mm effective cover width and nominal 28 . 3 mm deep ribs with subtle square fluting in the five pan at nominal 203 mm and centre to centre , the feed material for sheet is manufactured out 0 . 45 mm base metal thickness ( bmt ) , ( 0 . 50 mm tct , colour coating thickness is over and above the thickness stated above ) hi-tensil steel with minimum 550 mpa yield strength , metalic hot dip coated with zinc/aluminum alloy ( 55% aluminium , 45 %zinc ) as per as 1397 zincalume/galvalume az 150 ( minimum 150 grams per square meter , total on both side ) of steel make having the license of b ethlehem international engineering corporation ( biec ) the paint shall have a total coating thickness of nominal 35 um , comprisuing of nominal 20 um exterior coat on top surface and nominal 5 um reverse coat on back surface over nominal 5 um primer coat on both side of approved color shade for the sheets by the concern authority , the sheets shall have brand marking of the manufacturer giving product details on the back of the sheets at every 1 meter- 3meter c/c for confirming genuinnity of the material .