Steel Buildings in Europe

Part 8: Building Envelope 8 - 6 1 2 1 Thickness (0,4 – 0,7 mm) 2 Profile height (18 – 20 mm) Figure 2.3 Liner sheet profile The shallow liner sheets are not strong enough to walk on, so it is essential that the insulation, spacer system and weather sheet are installed from boards or access platforms, as illustrated in Figure 2.4. However, they do provide a non-fragile barrier against falling once they have been fully fastened. Where walking access is required, it is common practice to replace the shallow liner profile with a more substantial sheet (i.e. 32 mm to 35 mm trapezoidal profile in 0,7 mm gauge steel). Figure 2.4 Liner sheet installation progressing into the span of the purlins. 2.2.2 Insulation The primary function of the insulation layer is to provide a barrier to the flow of heat between the interior of the building and the external environment. The thickness of the insulation layer in roof and wall assemblies has increased significantly in recent years from approximately 80 mm in the 1980s to values approaching 200 mm in 2009. Further increases in thickness are expected over the next few years as the regulations on energy use in buildings become more onerous. The most common form of insulation in built-up cladding systems is mineral wool quilt, which is favoured due to its light weight, low thermal conductivity, ease of handling and relatively low cost. Rigid mineral wool slabs are available, but are less deformable than mineral wool quilts, giving rise to the