Various important factors and tips to good shelter design
Stay with companies that build concrete underground shelters on site. Although they may cost more, they offer the highest level of protection.
Concrete (poured on site) underground shelters are safest and strongest. When purchasing an underground shelter, make sure that it is concrete and built on the construction site. A minimum of 8 inches of concrete and at least 3 to 4 feet of dirt coverage is needed to provide optimal strength and safety.
Your nuclear biochemical filters and blast doors are extremely important. Products that follow the Swiss Civil Defense safety standards for bomb shelters are an excellent choice.
Go with underground shelter construction companies that insure your privacy. Also see if they will ship your shelter equipment/supplies, such as blast doors and NBC filters, to a drop location, as this will also keep confidentiality.
It's important when you are down in the shelter that you know what is going on above ground. This is why we recommend a security system that will detect intrusion onto your property with cameras that can record to a digital video recorder (DVR) to make sure the coast is clear before surfacing.
If a Radiation causing event has occurred, such as gamma radiation from a solar flare or fallout from either a nuclear power plant melt down or thermonuclear warhead, then a remote quality Geiger counter which measures alpha, gamma and beta radiation levels above which can be observed within the shelter below can indicate whether outside exposure levels are safe or not.
Underground shelters are great for food storage, gun vaults, and safe rooms to protect you and your family. In the event of a nuclear, biological or chemical attack it is important to filter the air into the shelter using an NBC filter to protect your breathable air.