A sandwich-panel façade requires supports arranged in line with the direction in which the cladding is laid. In many industrial halls this role is performed by cold-formed channels. Their open section makes certain connections and framing easier to execute. This does not mean, however, that any channel will suit every panel. Good preparation of the wall begins with a coordinated drawing of the purlins, panels, openings and fixing details. The primary task of a purlin is to transfer the cladding loads to the main structure. In a typical arrangement the horizontal member spans between columns. Wind load reaches it through the panels and fasteners. The weight of the wall also requires a defined path of transfer to the supports.

Long cold-formed profiles require planned unloading. Their low weight relative to their dimensions does not mean that packs can be grabbed and moved at will. The geometry of the cross-sections, the surface and the markings must be protected. A well-prepared storage area also makes subsequent panel installation easier. The crew finds the required zed purlins, channels, sigma and omega profiles more quickly instead of having to dismantle several stacks at once. The storage area should be stable, accessible and suited to the length of the elements. Access for the unloading equipment and a safe working area must be provided for. The subsequent direction of transport on site is also important. It is not worth placing packs where they will have to be moved again shortly afterwards.