Sigma has a more complex web than a standard C profile. The contractor must therefore pay attention to the actual contact surfaces and the position of the holes. Careful preparation helps to exploit the advantages of this section. However, one should not expect the additional bends to forgive every mistake. Cold-formed profiles perform in accordance with the design only when their geometry and fixings remain consistent with the assumed conditions. The height of the sigma profile alone is not sufficient to prepare the detail. The flange widths, sheet thickness and the run of the bends are needed. The bend radii and the position of the edge stiffeners are also important. The shop drawing should clearly indicate the orientation of the element. This allows assessment of whether the support and the fastener land in the right place.

A profile can arrive on site in good condition and still be damaged before it becomes part of the structure. Poorly prepared storage is a common cause. Moisture, uneven support and repeated handling are bad for thin components. Galvanised profiles need protection from water and from deformation. The storage plan does not have to be complicated. It must, however, match the material lengths and the actual sequence of work. The ground should allow packs to be laid down stably and equipment to be accessed safely. Water traps and places exposed to accidental impacts must be ruled out. Distance from the ground is also important. Cold-formed profiles should not lie directly on a wet surface. It is worth planning the bearers and their layout rather than looking for random boards during unloading.