Arena surface - just rubber?

[AngelFeb09]

I am looking into building my own arena and have planned for installing all the correct membranes, drainage pipes and including digging down to the clay and laying clean hardcore. I as stuck as to what surface to use as I am on a really tight budget. I noticed that a silica sand base should be used which would cost me quite a lot. One quote for 120 tonnes was £5500. Could I just use rubber on its own as this seems to be a cheaper option? Does anyone know of an all rubber arena? is there a certain way to construct one? and how does it ride?
Thanks

 

[Bobbly]

I would imagine that rubber on its own may move too much, silica sand varies in quality too. I feel the sand is too deep in my manege, 4" as recommended with a 2" rubber topping. Whole lot is too dry and has now mulched in together, my manege is built into a slope and the drainage is too good. You will need planning consent too, anything that requires earthworks is considered an engineering project.

 

[Pigeon]

Yes and it floods!!