[mr48chev]

The only steel frame buildings I have known to have had rust issues are those where there were severe caustic or humidity conditions created inside the building it's self.

In Texas in the early 70's there was a long abandoned rendering plant building that guys used to sneak up to to scavenge some scrap metal, either to use or to sell for scrap. Now I believe that who ever owned the land was praying that someone would haul it all off. That metal was rusted and actually stunk even though it hadn't been used for over ten years before I ever saw it.

A section of the Seneca Foods juice plant I worked in had rust issues but that section had a lot of grape and apple juice and live steam plus the caustic solution to clean it around all the time and it never actually dried out. Other areas of the same plant that were the same age didn't have that problem.

Truthfully I'd say what ever correctly built building you put up will stand there until the day many years in the future that someone gets tired of looking at it and wants something else.

The only things that aren't going to work down there are untreated posts in the ground or untreated wood too close to ground level. I'd still go with the suggestions on the other thread on the subject of having concrete stub walls poured to keep what ever walls you have above ground level. That 12 inches or so of concrete will probably extend the life of the bulding 50 years.