Sandwich elements

 Sandwich panels are a composite form of construction incorporating both the internal and external leaves of a cavity wall with a layer of insulation 'sandwiched' between. The two leaves are connected to each other by a proprietary system which has been developed to avoid cold bridging issues. An internal finish may be required to the hand trowelled rear face. The outer leaf (minimum 80mm thick) is purely decorative whilst the internal leaf performs the structural function of the element. They can be either non loadbearing or loadbearing. Loadbearing sandwich panels

 It is also possible to stack a limited number of sandwich panels on top of each other on the front of the structural frame. The sandwich panels are simply restrained to the frame. The bottom panel is loaded onto a continuous foundation. The joints between inner skin of the upper panels are hard pointed to transfer loads to the panel below. The outer leaf is purely decorative and must have freedom to move in any direction. Soft joints should be used.

 Non structural sandwich panels perform purely an aesthetic function. A suitable primary support structure (steel or concrete) will need to be provided for this type of element. This will need to extend (at floor and column locations) to within close proximity of the rear face of the cladding and to achieve this some secondary steel work may be required. Each element will be independently fixed to the support structure and must have freedom to move in any direction. To accommodate this, tolerances must be given careful consideration and there should be no 'locking-in' of individual elements. Soft joints should be used.