I believe they were installed from the factory using the same seam sealer that they used between the panels. That's how I installed mine and they are all still ni place, just be sure that you clean the joints good first.
Also Zach it's good to see another Lincoln guy on here, I don't think I have ever noticed you on this board before. I see you are in electrical maintenance, where do you work at? I am in the same field, I work as a Combustion Turbine Specialist for Nebraska Public Power District down in Hallam. I travel between Hallam, Hebron, and McCook, and will be moving to our new plant north of Beatrice at the beginning of 2004.