Be safe when interpreting insulated panel load span data
Jonathan Arnold, Product Development Manager for Building Envelope products at Tata Steel, examines how to interpret data for load spans and wind loads with regard to insulated panels…
Buildings are subjected to a variety of loads throughout their lives and many of these loads are applied through the building envelope. The main consideration for envelope wall construction is wind and thermal load.
The magnitude of wind load is closely related to wind speed but also depends upon a number of factors associated with the shape and dimensions of the building and its local environment. We can help you at your design stage by providing indicative wind load calculations for your project.
The wind load maybe applied as a positive or negative pressure on the building, depending on the wind direction relative to the wall. The positive load is transferred directly through the cladding to its support and the main structure of the building, whilst the negative load requires the fasteners to provide resistance to the cladding and prevent detachment from the building structure.
The cladding, supporting steelwork and fasteners must all, therefore, be designed to resist the applied loads. Tata Steel has rigorously tested its panel systems in accordance with BS EN 14509 using independent test laboratories to provide declared structural performance figures for the panel. In conjunction with this panel testing we also work closely with our approved fastener suppliers to obtain fastener pull out performance into a range of steel rail and section sizes.
The results from this intensive testing programme have been used by the SCI to calculate load span performance for the panel system, which incorporates both panel strength and fastener pull out performance. This combined assessment provides the specifier with the peace of mind that both the panel and fastener layout has been independently checked and will satisfy the design load for the building.
The importance of fasteners on the load span performance can be best highlighted when considering a micro rib insulated wall panel system. For example the Trimapanel® FTF is a system from Tata Steel which is designed to span between portal frames. The secret fix joint design of this type of product minimises the number of fasteners per support to around 3 (dependant upon support width) and therefore over long spans the performance of these fasteners are critical.
Below are examples of the performance of this system firstly when considering the panel failure as the limiting factor (assuming it is fully restrained) and secondly when the actual system failure (i.e. combination of fastener and panel limits). Click the image to enlarge:
As you can see from the above it is essential that the fastener layout and performance is considered at an early stage in the building design.
All Tata Steel’s insulated panel data quote load span performance which uses this combined approach and will state a fastener layout and also a purlin / rail specification. However, if required, our Technical Department will be happy to produce bespoke tables to your specification.
Please contact us on 01244 892199 for further details
For further information on all Tata Steel metal cladding systems you can find literature downloads at our website or you can request a CPD on ‘Steel cladding systems for the non-domestic building envelope’.