Story of  Balsam Farm in Clare County Michigan by Wayne Jaynes

I just purchased a small farm with a 40 by 80 barn in fairly good shape, I plan to repair it and keep it in great shape. I’ve been told that it is best to keep hay in it or it will crumble, is this true? I don’t plan to fill it so I need your thoughts. The walls are gapped to apparently allow air to travel thru but I intend to cover the exterior with metal and possibly replace the roof metal with new. Is it possible to clean the roof metal and seal it so that it has a weathered look but with protection as I prefer the original look.

What are your thoughts as to what I should do?
Barn was built in 1949.