Cladding means non-loadbearing precast panels connected to a supporting structure. The ten basic design principles for cladding panels are shown in FIGURE 1.


FIGURE 1 Ten Design Principles for Cladding Panels

The preferred jointing system for high-rise cladding panels is the open-drained joint, FIGURE 2


FIGURE 2 Open-Drained Joint Details


FIGURE 3 Eccentric Forces

The following principles should be recognised in the design of connections for precast cladding units:

  • Connections must be detailed to ensure that each unit supports only its own weight and no weight is transferred from the units above.
  • Connections should be chosen so that the loads are transferred through the connections as simply as possible with minimal eccentricities. The design of the fixings must recognise all forces and allow for them in the detailed design, FIGURE 3.
  • Units should be provided with at least four fixings as shown in FIGURE 4. The arrows show the freedom of movement that must be provided at each of the fixings in the plane of the panel. The fixings must provide resistance to wind forces perpendicular to the plane of the panel. Panels must not bear on one another.
  • The connection details should be standardised as much as possible. This results in economy, speed and simplicity during production and erection, and also reduces the chance of error.

FIGURE 4 Typical Panel-Fixing Details

Typical Panel-Fixing Details

  • Adequate tolerances and clearances are required.
  • Connections should allow economical fabrication of the precast elements. The hardware should not interfere with concrete placement, cause finishing problems nor make it difficult to provide the specified cover to reinforcement.
  • Connections should be detailed so that hoisting equipment can be quickly released. It may be necessary to provide temporary connections that are released after final adjustments are made.
  • Typical cladding panel connection details are shown in FIGURE 5.

FIGURE 5 Typical Connection Details for Cladding Panels

Design for repetition; aim for the least number of variations between panels and increased repetition of mould usage for maximum economy.

Design for the largest possible panel size within the limits of transport, crane capacity and temporary support arrangements. This will reduce costs and close up the building more quickly.

Have the panels preglazed if possible.

Detail the panels so as to minimise the effects of weathering.

Consult Hanson early in the design process.