Air conditioner mounting wedge

My trailer is a very lightly used 2008 model. The Carrier air conditioner works fine except condensation water pours into the coach when used in humid conditions. It is a low profile unit and the installation instructions limit the slope of the roof to 5 degrees. Where mounted on mine the roof slope is 12 degrees. Carrier calls for a 14" square hoop wedge to level the unit in the instructions. Any ideas where I could pick one of these up? I could make one out of wood but would prefer something with no joints.

I am hoping leveling the unit will fix my water problem. No water drains onto the roof.