Installing cold-formed steel sections: what to prepare before delivery

Before production, the right-hand and left-hand elements, the direction of the flanges and the dimensioning base must be clarified. Z-sections may have different flanges, and sigma profiles additional web bends. A similar side view does not mean an identical orientation. In the documentation, it is worth noting how the element is positioned in space so that its marking corresponds to the actual installation.

Long profiles are light per metre, but the bundle may have considerable mass. Lifting requires suitable equipment and defined support points. The possibility of excessive deflection, twisting or crushing of thin walls must be limited. The organisational details should follow from the delivery and the work plan.

The prepared storage place should be stable and allow later access. It is worth separating the bundles according to the installation stages. Moving the entire delivery in search of a few purlins increases the risk of damage. Galvanised profiles should not be dragged over the ground or over other elements in a way that damages the surface.

When organising the site, a list of bundles with element numbers and their place in the structure is useful. The bundle intended for the first field should not be blocked by material needed at the end. This simple division limits moving and helps to maintain clear markings throughout the installation.

The markings of cross-sections, lengths, holes and the condition of the surface must be checked. A product made of a different sheet thickness may look very similar. It is worth clarifying a discrepancy immediately instead of assuming that the difference is insignificant. In a thin-walled structure, geometry and material are the basis of the design assumptions.

A comparison with element numbers and positions on the drawing makes checking easier. Fasteners, washers, support tables and stiffening parts should be listed separately. The absence of a small accessory can stop the installation of an entire roof section. The price of such a stoppage is often greater than the saving obtained from a simplified order.

Galvanised profiles require storage in accordance with the supplier’s recommendations. Water trapped in a tight bundle should not remain there for many days. Conditions enabling drying and ventilation of the material are needed. Covering with foil alone does not solve the problem if moisture remains enclosed beneath it.

Weather and temperature differences should be taken into account. Condensation may also appear inside the room after cold elements are brought in. Checking the bundle after delivery is therefore as important as protection against rain. Well-organised storage limits later cleaning and disputes about the condition of the coating.

A single installed profile does not always have the working conditions envisaged for the completed structure. Full stiffening may arise only after further connections, bracing or enclosure are made. The sequence and safeguards indicated in the installation plan must be followed. Decisions must not be based solely on the fact that the beam stands straight without load.

This applies to Z-sections, channels and sigma profiles. Even a small element can perform an important function in maintaining the geometry of the entire system. Temporary loading of the roof slope with bundles of material requires separate assessment. The distribution of the delivery on the roof must not result solely from the crew’s convenience or the reach of the lifting equipment.

The type of bolt or screw, the number of fasteners and the manner of their installation should comply with the design. Not every bolt that fits the hole is an equivalent replacement. The properties of the fastener, the washer and the connected parts matter. For connections, the requirements for the specific system must be applied.

If the holes do not fit, the cause must first be established. It may be a reversed element, an error in setting the support or an incorrect drawing version. Arbitrary reaming and cutting should not be the first solution. Cold-formed profiles have defined force-transfer zones that can be weakened by a seemingly small correction.

Before covering the structure, it is worth checking the completeness of connections, the alignment of beams and the condition of the coating. Residues from cutting and drilling must be removed. Any deviations should be clarified and recorded in the documentation. After the panels are installed, access to many places will be more difficult.

Omegas in a light grid also require checking of spacing, plane and fixings. A small cross-section does not mean little importance for the finished cladding. A well-prepared installation of galvanised profiles limits the number of improvised actions. It is precisely the predictability of the work that gives real time savings and allows the advantages of prefabricated elements to be used.