From the choices below, select the material with the highest R value?

From the choices below, select the material with the highest R value?

• A. Brick
• B. Wood
• C. Concrete
• D. Steel

Answer: (B)

R-value measures how well a material resists heat flow—the higher the R-value, the better the insulation. Wood tends to have the greatest resistance to heat transfer among these options because its cellular structure traps air and lowers heat flow. Brick and concrete are dense and conduct heat more readily, giving them lower resistance, while steel is a metal with high thermal conductivity, meaning heat moves through it easily and it offers little resistance. So, among these materials, wood has the highest R-value and thus the best insulating performance.

R-value measures how well a material resists heat flow—the higher the R-value, the better the insulation. Wood tends to have the greatest resistance to heat transfer among these options because its cellular structure traps air and lowers heat flow. Brick and concrete are dense and conduct heat more readily, giving them lower resistance, while steel is a metal with high thermal conductivity, meaning heat moves through it easily and it offers little resistance. So, among these materials, wood has the highest R-value and thus the best insulating performance.