Residential window flashing corrosion and replacement

Tom's house replaced terne plate flats with copper (not plastic, despite the price difference: $5,000 plastic vs $9,000 copper). Used to teach copper's atmospheric corrosion resistance and the role of UV degradation in plastics.

I just had some — probably terne plate — I had some flats on some windows. My bedroom in my house is eighty-five years old. They had some that was just steel, been there for about eighty-five years. Just a year ago it was starting to show a little rust. I think it was probably terne plate. Back in 1930, during the Depression, you could buy all the terne plate you wanted — steel with a thin layer of lead to protect it.