Further to Issue # 1 being the heat impact onto the resins within composites, a potential solution was worked on today.
2 things happened separately but all within the same period of time.
1 - We researched different types of panels to see what is available to reduce the heat from the outside layer to the core structural member. We found a few options, but one of them is a natural material (renewable / low carbon footprint) which is where we ended up concentrating on as the heat properties here are incredible withstanding heat of up to 1,200 deg which is exactly what we need. The weight is a bit heavier than we hoped, so looking at a few scenarios to see what thickness is best. Cost for this is within budget so this is good.
2 - The supplier of our fire retardant layer (who also worked with ACS-A in their development) has a video on their website showing a simple 2.2mm thick fibreglass extruded panel with their fire retardant outside and they had a reduction from approx 800 deg to 300 deg continuous for 30mins (this is all that is required for a residential house). It was amazing to see such a heat loss over such a thin non-heat specific system. So we we apply the same fire retardant to our 13mm thick specific system we feel the 1,100 deg target down to 200 deg will be achievable. Only a fire / heat test using our system will answer this question. This is planned for asap.
What could have been a crippling issue at the start of this week now seems to be resolved. The system as a result of further discussions this week is now more simple yet better for a few reasons. Great result!