New Hot State Member capacity tool launched to decrease time and cost for designers and engineers
This week, North Yorkshire, leading structural and civil engineering practice MMCEngineer Ltd launched groundbreaking tool to calculate Hot State Member Capacity and fire ratings.
The new tool which has taken 5 years to develop can calculate Hot State Member Capacities for #LGS as well as offering a fire rating based on board manufacturer test data.
Using this test data specifiers, designers and Engineers are now able to specify studs and boards required at the earliest possible stage, freezing the design early and speeding up the design process.
The ability to conduct these calculations is required due to the finite capacity of test rigs the world over. Clause 13 of EN1365-1 lists changes that can be made to the as-built / designed structure without invalidating the test report and data and this includes as point ‘h’, that load applied can only be decreased.
As well as finite capacity of the rigs the cost of testing is relatively high and can be a barrier to entry to the industry for new suppliers. Using techniques proposed by MMCEngineer Ltd the costs are vastly reduced and offer infinite load application unlike physical rigs.
The MMCEngineer solution has been developed based on Euro Codes and British Standards – both of which have been around for over ten years – and developed with input from some of the leading lights in the fire industry. MMC's Stephen Napper CEng has presented our proposal at the I Struct E Structures in Fire Forum where it was very well received.
The member checks are comparable to the ambient member checks carried out daily by Engineers across the globe.
The checks use many elements of, the ambient member checks using reduced yield strengths and Youngs Modulus in line with the ‘hot flange’ temperatures specified in the board manufacturers test data and the reduction factors specified for those temperatures in the standards.
At launch the tool incorprates data available from James Hardie and Fermacell boards, and we will receive data from other board manufacturers in due course. ***UPDATE*** 14th November 2025, Knauf Board data added
Using our plug in for Tedds and linking to Tekla Structures for example users can:
Design LGS portal frames in moments – these are lighter than traditional HR steel portals, but only at their most effective upto 20m span, when HR frames work best anyway.
Recently, MMCEngineer Ltd wrote and had approved by the SCI on behalf of NHBC a Stage 1 LGS manual for Birkbeck Structures which covers up to Fifteen Stories which is far more, using their concrete floors, than a load bearing test rig can apply load to simulate
MMCEngineer founder and Engineer Stephen Napper CEng commented
"Our methodology will prove invaluable to their clients submitting designs to the BSA. When they are asked to demonstrate that they can provide fire safe designs at these heights and loads. they will have somethign accurate to hand."
Designs using these tools relative to the ambient state checks
Selling copies of the design guide which includes:
worked examples to hot state checks,
zero load factor examples and
ambient state checks for the same members
Indicative floor joist designs using various floor loads to illustrate real world loads
If you'd like a copy of the design guide please use the Contact Form at the bottom of the page or use the payment link or request an invoice. We also have a FAQ that answers the most common questions people have asked us about the work.
In time our sister company, Modern Engineered Software Solutions Ltd will be adding the calculations to the plug in’s available for Tedds. This update will be released in due time.
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