All roofs have to meet minimum standards of protection in the above categories. In geographic areas where the weather is severe or the chance of fire is greater, metal is a sound choice. Most metal products will withstand winds up to 120 miles per hour. The impact resistance is usually a Class 4 rating, which means that the roof will resist dents even with hail as large as two inches dropping at a high velocity. Metal will not burn, so it protects homes from forest fires.