What is the approximate thickness of copper weighing 32 oz with a B&S gauge of 17?

What is the approximate thickness of copper weighing 32 oz with a B&S gauge of 17?

• A. 0.02 in
• B. 0.04 in
• C. 0.06 in
• D. 0.08 in

Answer: (B)

Copper thickness in roofing is often described as ounces per square foot, so 32 oz means 2 pounds per square foot. To translate that into thickness, use copper’s density, about 0.324 pounds per cubic inch. For one square foot (144 square inches) the weight is 0.324 × thickness × 144 ≈ 46.656 × thickness pounds per square foot. Setting this equal to 2 pounds per square foot and solving gives thickness ≈ 2 / 46.656 ≈ 0.0429 inches, which is about 0.04 inches. The gauge 17 mapping for copper is in this same vicinity, so the approximate thickness is 0.04 inches.

Copper thickness in roofing is often described as ounces per square foot, so 32 oz means 2 pounds per square foot. To translate that into thickness, use copper’s density, about 0.324 pounds per cubic inch. For one square foot (144 square inches) the weight is 0.324 × thickness × 144 ≈ 46.656 × thickness pounds per square foot. Setting this equal to 2 pounds per square foot and solving gives thickness ≈ 2 / 46.656 ≈ 0.0429 inches, which is about 0.04 inches. The gauge 17 mapping for copper is in this same vicinity, so the approximate thickness is 0.04 inches.