Steel profiles as wall girts for sandwich panels

Wall sandwich panels are not fixed to arbitrary parts of a building frame. They are usually supported by a system of wall girts that transfers loads from the cladding to the columns and other parts of the primary structure. Properly selected Z, C or SIGMA steel profiles can serve as wall girts.

Girt selection affects not only structural safety but also the correct installation, weathertightness and appearance of the sandwich-panel façade. Profile sections and spacing should therefore be determined by the design and the declared properties of the cladding system.

What is the function of a wall girt?

Girts are horizontal members of a wall structure. They support sandwich panels or profiled metal sheets and transfer loads acting on the cladding, primarily wind pressure and suction, to the building’s main structure.

The girt system may also provide support around windows, gates and doors. These areas often require additional framing members. Their location should be established before the profiles and panels are ordered.

What determines wall-girt spacing?

There is no single spacing suitable for every building. It depends on:

• the type, thickness and performance of the wall sandwich panel,
• whether the panels are installed vertically or horizontally,
• the height and location of the building,
• design wind loads,
• the spacing of the primary columns,
• gates, doors, windows and other openings,
• permissible deflection of the profiles and cladding,
• the panel fixing arrangement.

Panel manufacturers specify permissible spans for defined support and loading conditions. These values must be checked against the structural calculations for the building. Increasing girt spacing without verification can cause excessive panel deflection, joint problems or wind damage to the cladding.

C, Z or SIGMA profile – which section should be used?

C profiles are frequently used as single-span girts, trimming members and secondary framing around openings. Z profiles allow appropriately designed overlaps and can be used in multi-span systems. The more developed geometry of SIGMA profiles can provide an advantageous relationship between stiffness and member weight.

None of these sections is automatically the best choice in every situation. Selection depends on loads, span, support conditions, permissible deflection and the connection arrangement specified by the structural engineer.

What should be checked before ordering wall girts?

The following information is useful when preparing a quotation:

• structural and elevation drawings,
• column spacing and wall height,
• the panel type and installation orientation,
• the size and location of gates, doors and windows,
• the required profile section, thickness and length,
• hole patterns and connection details,
• the required corrosion protection,
• the number of members and planned installation date.

Factory-prepared holes can make installation more efficient, but their positions must comply with the documentation. Additional holes should not be made without verification, as they may weaken the profile or interfere with designed connections.

Wall girts as part of a complete cladding system

A correctly selected profile is not sufficient if the remaining cladding components do not form a coordinated system. Fasteners, fixing patterns, seals and flashings at the plinth, corners and openings must also be considered.

e-PROJECT21 supplies Z, C and SIGMA steel profiles used as wall girts and other components of lightweight steel structures. For larger projects, material supply can be combined with sandwich-panel hall design, hall construction or sandwich-panel installation.

The section, spacing, support conditions and connections of wall girts should be specified by a suitably qualified structural designer according to the selected panel, building geometry and site-specific loads.