Fixed in the light steel keel h19 what it means
Flat roof if the level of the width of the width of 300mm between the expansion area can be calculated by the same material can be combined with the amount of calculation, which refers to the width of the horizontal distance. The difference between the height should be the vertical height difference, the calculation of the rules described> 300mm width can be calculated by the expansion area, the expansion of the vertical height size.
H type, specifications (H type light steel keel height) 19mm.
