cover for splash pool

[kel123]

hi guys

I am fencing in my 15' dia spash pool to stop my 3 year old grandson from getting anywhere near it.

To make it easier I am making the surround square (panels and posts) half lap and half trallis. It will be approx 18" higher on the one side and I am considerring putting a roof on. It will be approx 16' square so the slope will be aprox 16.1' plus some overhang for gutterring.

I am thinking of using clear corrigated plastic. so what is the best way to support it. If I use 8' x 2' sheets do you think one cross member will surfice and what is the cheapest way of doing this cross member

I know the slope should be greater than this but there are limitations, my intension is to glue the sheets together to stop the capilary action.

any thoughts