I guess Hazel or Muzzy can help me here.

Im not a complete novice with fibreglass- i have made a sports car body but it was all curves with returned edges making it easy to stay rigid.

I have made a buck and taken a useable mould from it - once again nothing to taxing as a wooden frame was laminated in to make it rigid.

So the question is - what advice on lay up and thickness should i make the actual roof moulding.

It is just a roof panel like the Manxter - im considering using combination mat or rovings into the centre which is mainly flat to try to re inforce this area and sandwich it it csm.

I normally use 300 - 400 weight cloth so whats the minimum layup can i get away with as i dont want it overly heavy but obviosly it will be a large kite catching the wind attached to the cage.

Thanks guys

high m8 made mine up out of 2 layers of 900gsm then put 2 round tubes one across the front then one just in front of the role bar to add strengh from one side to the other, not to heavy but strong

Yep, what he said. 

We do 2 layers with an extra layer (kind of) around the edges and we add a couple of baton strips, about 2inches thick, each side front to back, about 4/5 inches in from either side, with a layer or so over these.
I think as long as the edges stiff you should be safe 

 
Thanks thats much appreciated