Common material halving thicknesses (inches) taken from various Western emergency management agencies and military publications. Remember you will want MINIMUM total Protection Factor of 10 from what is OUTSIDE which is just over 3 halving thickness to reduce radiation by 90%. In areas of heavy fallout (greater than 10 rad/rem per hour or 100mSv/hr) known as the "DFZ" or Dangerous Fallout Zone you might need a PF of 20, 50 or even 100. If you are in the basement of a 2 story wood frame house you will get a PF of 12-15 there so you might not need shielding. However upstairs the ground level floor will only get a PF of 2 so you will need to make a shelter or add shielding of up to 3 halving thicknesses to get an additional PF of 8 to bring up your total PF to10.
Lead - 0.4
Steel - 1.0
Concrete - 2.4
Red Bricks - 3.4
Sand or packed dirt - 3.6
Broken Antracite coal - 6.0
Ice - 6.8
Water - 7.2
Books/Magazines (depends on density) - 8.0
Wood - 11.0 (depends on density)
Snow - 20.0
Density of common material relative to concrete is listed below, use this table to help you figure out how much material you need to reach a PF of 10+ which is about 3.5 halving thickness. Remember for concrete one halving thickness is 2.4 inches.
