Steel Buildings in Europe

Part 8: Building Envelope 8 - 2 2 1 3 4 5 1 Profiled steel roof cladding 2 Wall cladding 3 Purlins 4 Side rails 5 Primary steel frame Figure 1.1 Principal building components There are essentially three layers to the structure: 1. The primary steel frame, consisting of columns, rafters and bracing. The example shown in Figure 1.1 is a portal frame, but the guidance given in this publication is also applicable to other types of structure. 2. The secondary steelwork, consisting of side rails for the walls and purlins for the roof. These members serve three purposes: - To support the cladding - To transfer load from the cladding to the primary steel frame - To restrain the primary steel frame members (see Section 4.5 on limitations on such use) . 3. The roof and wall cladding, whose functions include some or all of the following: - Separating the enclosed space from the external environment - Transferring load to the secondary steelwork - Restraining the secondary steelwork - Providing thermal insulation - Providing acoustic insulation - Preventing fire spread - Providing an airtight envelope