Decking sheet selection should be based on the floor design, not only the profile size. For engineers, the important points are the deck span, sheet thickness, support spacing, concrete depth, construction-stage loading and final floor loading. During concrete casting, the steel deck may carry the weight of wet concrete and construction loads before the concrete reaches its required strength. After curing, the complete floor system is checked for strength and deflection. This is why the 45/150 mm and 75/300 mm profiles should be selected according to the structural design rather than simply choosing the deeper profile.