What is a common material used for vent piping in plumbing systems?

Cast iron is commonly used for vent piping in plumbing systems due to its durability, resistance to high temperatures, and ability to effectively dampen sound. Its weight and structural integrity make it suitable for both vertical and horizontal installations, allowing for a reliable venting solution that can handle the demands of waste and vent systems. Additionally, cast iron is not susceptible to corrosion in the same manner as some other materials, enhancing its longevity in venting applications. The use of cast iron in vent piping is a traditional choice that has been proven effective in various plumbing scenarios.