I’m going to act daft here but feel the need to ask what others choose (or have been advised by their AB’s) to do…..
Where you have a roof of asbestos cement profile sheet on a steel portal (or similar) frame it’s easy enough to select from the Inference options (under >Project Database>Constructions for Roofs>) to get what is required but what do you do when the same roof construction is applied to the vertical walls (usually above a brick or block boundary wall to 2m or thereabouts). You can’t select the same options within >Project Database>Constructions for Walls> and you nearly always end up with wildly different U Value whatever you select.
If you instead choose to call this vertical element a roof rather than a wall you can then use the selections available from the Inference options (under >Project Database>Constructions for Roofs>) but, when it comes to input and you identify your element as a roof and select the Project Database item you’ve set up, you can identify the orientation, lets say North, but when you set the pitch to 90 degrees (i.e., vertical) iSBEM says this is out of validated range and rejects it. You could select 89 degrees but this seems like cheating.
Another option might be to simply set up a >Project Database>Constructions for Wall> using the >Project Database>Construction for Walls>Introduce my own values> option and copy the U-value and Km value from the item you have set up under the >Constructions for Roofs> tab for the pitched or flat parts. Whilst not able to evidence this introduced value with the SAP calculation and details of the qualified person who has provided it, surely site notes to explain that the values are from within iSBEM itself (or at least from the issued construction database) should be sufficient……
….or am I making too many assumptions along the way?
Thoughts anyone?
Grahame.
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