skinning with Alum on 5ft wide trailer

I am trying to determine how to skin my five foot wide trailer with aluminum. The sides are a no brainer and I have found lots of info on that. However the top is another story. Five foot wide aluminum does not seem to be available any where. So I assume I will have to join sheets together in order to cover the entire width and then overlap the edges at a spar. Any suggestions out there? 
