How does concrete compare with other materials in respect to shielding?
Shielding value seems to be almost entirely related to mass, and as a result even normal-weight concrete has an advantage over most other materials. Speaking in generalities, 8 inches of normal concrete (around 150 pounds per cubic foot) provides about the same amount of shielding as 30 inches of wood, 12 inches of earth or 16 inches of books.