I'm looking for help on planning a roof over a deck I plan on adding to my house. The roof will be 18' wide and extend out 12' from the house. I want to have at least a 1' overhang on each side making the roof 12x20.
I plan on using polycarbonate sheets as roofing so it does not need to support much weight. Building in a location that does not experience snow. What size post and beam do I need to use to span the 18' between support posts?
Here is the concept design.