The NZ Metal Roof and Wall Cladding Code of Practice is a comprehensive design & installation guide, and a recognised related document for Acceptable Solution E2/AS1 of the NZ Building Code.
When sheets are to be stored on the ground, they must be stacked horizontally on a firm and level surface on top of cross-stacked untreated timber fillets, inclined slightly for rainwater runoff and be covered with a loose tarpaulin allowing air to circulate.
Sheets should be stacked in sheltered positions preferably near areas of the building where it is to be fixed, and they should be stacked in the order in which they will be used.
The height of such stacks should not exceed 1 m, and they should be clear of the ground. If it is necessary to stack sheets in an exposed position, they should be secured against any movement by the wind.
Once packs are opened and laying of the roof or wall cladding commences, a continual visual check should be made to ensure the surface of the sheets are free of any noticeable defect or damage. This is particularly important with pre-coated materials.