Why is a steel roof considered a bad match with an aluminum vent?

A steel roof is considered a bad match with an aluminum vent primarily due to the potential for a galvanic reaction. When two different metals, such as steel and aluminum, are in direct contact in the presence of moisture, there is a risk of galvanic corrosion. This occurs because the more noble metal (in this case, aluminum) can corrode more quickly when in contact with a less noble metal (like steel). Over time, this reaction can compromise the integrity of the materials, leading to deterioration and potential leaks or failures in the roofing system.

Understanding the principles of galvanic corrosion is essential for roofing professionals, as it highlights the importance of compatible materials to ensure durability and longevity of roofing installations. This knowledge directly impacts material selection during the design and repair phases of roofing systems.