As an adjunct to the other thread on fallout, some questions: I understand radiation is DIRECTIONAL. Therefore, it seems apparent that just descending into a full basement will solve the bulk of exposure issues. This provided you've shut off all HVAC systems that might still be functioning, taped up the entrance and donned an N95 at minimum. No radiation will come up from the floor, obviously, and all four directions around you are also blocked by earth. The remaining direction is what comes from above. If the house survives a blast some distance away, fallout could still land on the roof and that appears to be the remaining threat. Unaugmented, the radiation has to travel through: Asphalt shingles, the wood roof, 8' of attic airspace, The attic floor/main level ceiling 8' of living level airspace, main level floor/basement ceiling I guess it again falls to type of fissile material and amount of fallout, but if the house survives undamaged otherwise and I don't have time to create overhead barriers, is this survivable, or will the two weeks i spend down there just cook me?