Ok well that would certainly reduce cost by not having to use a deck, do you think I could get away with resting the rafters panels directly on top of the French doors with these panels or are they were heavy? Or do you still think a 100mm ish wooden lintel is necessary, I mean the only weight it will ever really support is the roof itself and and snow or heavy rain???
Heavy? No, one person can easily manage a sheet length. The lintel you have at the moment looks adequate, if it is sound. I think the other poster over stated the snow loading, snow is not that heavy and never persists for long in most of the UK.
Did some research so I understand more, bit which thickness do you think I can get away with? Do you mind me asking where you bought yours and what thickness you chose?
If you plan to need to step on it, get the next thinnest up from the thinnest version, otherwise it will dent with your weight. If you have no intention of stepping on it, or you don't mind laying timbers in the channels for extra support when you do, you can get away with the thinner material.
I bought mine from two different sources, workshop roof first, because I built that several years after the main garage, then I decided to replace the garage roof. Any large builders merchant will be able to source it for you, ring around once you know what you need, and invite quotes, delivered. Don't forget the special screws, they are like a large wood screw, with a hexagon head, including a rubber seal. I vaguely remember paying around £15 per sheet, for the uninsulated version.
Until 5 years ago, there was a massive Rolls Royce turbine blade factory, built 50 years ago and 1/4 square. Walls and roof were built from this same material. It stood derelict for it's final decade, but no sign of any deterioration. The site is now developed into a Lidl, Home Bargains and etc..