A below ground storm shelter should be considered a necessity by anyone living in, or even near, an area prone to hurricanes or tornadoes. Obviously, if you can build your own below ground storm shelter – you’ll be able to save some money compared to buying a pre-fabricated one. However, the more important point is to have one and then, of course, not to neglect it. Like any building it will need regular maintenance to make sure it’s ready to ‘do the job’ when called on.
Unless it is to be constructed in the cellar of a house, a below ground storm shelter requires a pit to excavated into which it will be located. Some issues arise when considering this aspect of a below ground storm shelter. Whilst this should only arise as an issue if you’re buying a pre-fabricated storm shelter, do you have sufficient room to dig the pit required for it?
Remember as well, to get the digging equipment in place to do the excavation may require access to a neighbors land – if that is the case, are your neighbors likely to agree to an excavator trundling over their land? Whether building your own or buying a storm shelter, you’ll need to be wary of any pipes or cables in the area of your excavation. Cutting through a utility pipe or cable can be costly as well as inconvenient!
If you’re building your own below ground storm shelter you’d be well advised to at least hire someone to do the excavation work. They’ll know how to operate the excavator safely and will probably already have an understanding of the local bedrock and water-table levels; two more things you need to be aware of prior to starting the excavation.
Storm Shelter Design Considerations
If you’re resident in the United States of America, quite simply you must primarily consult and conform to the standards laid down by the ‘National Storm Shelter Association’; which are freely available from their web-site. Basically a below ground storm shelter should protect you from: extreme changes in pressure, strong winds and projectiles. Many people don’t appreciate the importance of the pressure change effect when constructing a storm shelter.
We all see hurricanes and tornadoes as events that demolish trees and buildings or throw objects through the air. However, being underground will not protect you from an extreme change in pressure if your storm shelter isn’t built to the correct standards.
There is a scenario in which the difference in air pressure above and below ground can be that great that a below ground storm shelter could simply be forced to burst outwards – just due to the air pressure! The problem is easily addressed by the correct fitting of ventilation pipes to control the internal air pressure; but without reading the guidance – you won’t know what to do to make your underground storm shelter truly safe for you and your family.
When considering the location for a below ground storm shelter it needs to be close enough to reach quickly from the main residence. Whilst normally as soon as a tornado or hurricane is known to be imminent you would go to the storm shelter, it might be that you have little warning or opportunity to get to it. Subsequently, you do not want to have a long walk/run to the shelter with debris etc flying around you.
When constructing the shelter make sure that the steps/stairs down into it are not too steep and that they have sturdy handrails for younger/elderly people to use. A good tip also is; if a storms forecast – leave the shelter unlocked. Imagine the nightmare of not being able to find the keys or operate a lock as a storm approached.
See Also: Metal Storm Shelters