Z steel and C steel contrast
When the roof slope is small, the bending modulus of Z-type purlin is slightly greater than that of C-type purlin, but the
difference is not significant. When the roof slope increases, the efficiency of the flexural modulus of z-type purlin
symmetrical in the vertical direction increases. Therefore, Z-purlin is suitable for the roof with a larger slope. For metope,
choosing Z or C does not make much difference. If a purlin is to be made into a continuous member, it is best to Z purlin,
because it is easy to lap.