What is the main lightweight roofing material commonly used?

Aluminum is considered one of the main lightweight roofing materials because it has a very favorable strength-to-weight ratio, making it easy to handle and install compared to heavier materials like steel or concrete. Aluminum's lightweight nature allows for reduced structural support requirements in buildings, which can lead to cost savings and more efficient construction practices. Additionally, aluminum is highly resistant to corrosion and is durable, which contributes to its popularity as a roofing material in various applications, especially in environments where resistance to the elements is crucial. Its ability to be molded into various shapes and reused or recycled further enhances its appeal as a sustainable roofing option.

Other materials listed, while they may have their uses, do not fit the lightweight characteristic as effectively or have specific drawbacks that limit their application in roofing.