What happens when you use iron nails in a Copper roof?

When iron nails are used in a copper roof, the iron will react with the copper in the presence of moisture, leading to a chemical reaction known as galvanic corrosion. This can cause the nails to deteriorate faster and weaken the structural integrity of the roof over time. It is recommended to use copper nails or stainless steel nails in a copper roof to prevent this issue.