Metal Underlayment - Asphalt Shingles?


Inspected an oldie today (built in 1870). Visible between the wood plank roof decking looked like sheet metal. Pretty typical to see some other form of roof decking installed over the wood planks, but I’ve never seen metal. Anyone see this before? And why? Thanks


Maybe it’s an old roof?

Was this home in the Cities, or more likely a farmhouse? If farmhouse, it is most likely the original roof. The structure may have had other uses until the family needed the extra room and combined it with, or converted it to, the main home. I see a lot of such practices being in rural Southern Minnesota. There’s a ton of historic building practices in these old places if you pay attention.