Overview
There are two main types of home storm shelters: below-ground and above-ground. Both offer near-absolute protection from tornados when designed, constructed, and installed according to the rigorous FEMA guidelines and ICC standards. In fact, FEMA states, “If a safe room meets all of the requirements of FEMA P-361, an above-ground safe room is just as safe as a below-ground or in-ground safe room” (Taking Shelter from the Storm: Building or Installing a Safe Room for Your Home, FEMA P-320, March 2021, 28).
Regardless of the data and test results, many believe being underground is the safest option. Personal preference is one of the many factors to consider when deciding on a home storm shelter. So, pick a shelter that complies with the stringent FEMA guidelines and ICC standards, meets your family’s needs, and gives you peace of mind and confidence in your decision.
This article will briefly overview each type of shelter’s primary advantages and disadvantages. To be clear, I’m referring to modern shelters that meet the guidelines and standards I referenced above. All of these shelters provide near-absolute protection from tornadoes. So, I am not talking about old root cellars converted to storm shelters, DIY shelters that weren’t built using the FEMA guidelines and ICC standard, or shelters that were manufactured pre-FEMA guidelines, even though all of these may provide some protection.
Caveats
I did find some inconsistencies and subjectivity in my research.
For example, there are some geologically dependent differences. Some home storm shelter companies state that an underground shelter is typically less expensive to purchase and install than an above-ground shelter. Other companies claim an underground shelter is more costly due to excavation and installation complexities. Both statements are equally valid depending on the region and the geology of the installation site. In other words, “it depends”.
As another example, some companies list the potential for pest infestation as a disadvantage of an underground shelter. However, this could also apply to above-ground shelters installed on a concrete slab in the yard, a garage, or an unfinished basement. With proper preventative measures, pest infestation doesn’t need to be a problem in any storm shelter. As such, I didn’t include this as a disadvantage for either type of shelter.
Though this article will serve as one tool in your research, it is important to do your homework to determine which home storm shelter type is best for your particular situation.
I would like to include photos showing the various types of shelters, but I was unable to find images that are free to use without copyright violation (except for my own shelter, which is shown on the About page). If you work for a storm shelter company or you’ve previously purchased a home storm shelter and would like me to include a photo (with proper attribution) of your shelter, please get in touch with me.
Below Ground Shelters (Installed in the Yard)
These shelters are typically made from concrete, steel, or fiberglass. They are installed in the yard within 150 feet of an exit from the home.
Pros:
- Aesthetics: Underground shelters are typically less obtrusive and visible, which may be preferable for your property’s appearance.
- Temperature: Better natural temperature regulation since the shelter is below ground and insulated by soil. This may especially be beneficial in warmer climates.
The lack of “Pros” relative to the other shelter types is not a negative. As mentioned previously, all shelter types that meet or exceed FEMA/ICC guidelines and standards offer excellent protection.
Cons:
- Accessibility: Difficult or impossible for individuals in a wheelchair or with mobility challenges to access.
- Access Hazard: If in the yard, it may require going outside in a storm with dangerous hail, lightning, and flying debris to gain access, which puts you and your family at risk while seeking shelter.
- Installation Complexity: You must consider underground utilities and also ensure proper drainage. Moving the shelter into position may require removing fences or other obstacles for the excavator and other equipment. Your local municipality may also require permits.
- Water Intrusion Risk: May be susceptible to flooding, particularly with heavy rainfall or in areas with a high water table. Shelters with a sloped door slightly above ground (vs. parallel to the ground) have less risk of water intrusion.
- Maintenance: Generally requires more maintenance to prevent corrosion and water leakage.
Below Ground Shelters (Installed in the Garage)
These shelters, also known as Garage Floor Shelters or Garage Storm Shelters, are installed in the concrete slab of a garage or a covered carport where water intrusion won’t be a problem.
Pros:
- Aesthetics: Underground shelters are typically less obtrusive and visible, which may be preferable for your property’s appearance.
- Many have removable steps to make more space inside. The lightweight steps simply lift out and stack inside the shelter.
- Temperature: Better natural temperature regulation since the surrounding soil acts as insulation. This may especially be beneficial in warmer climates.
- Footprint: It does not utilize valuable garage space. Cars can drive and park directly over the shelter.
- Alternate Use: It can double as a mechanic’s pit for changing the oil or performing work underneath an automobile.
Cons:
- Accessibility: Access may be difficult or impossible for individuals in wheelchairs or with other mobility challenges. Also, it may require moving an automobile to gain access if there isn’t enough space in the garage.
- Ceiling Height: Many of these shelters have a height of 5′ or less, which may make some people feel claustrophobic.
- Water Intrusion Risk: It may be susceptible to flooding, particularly with heavy rainfall or in areas with a high water table. If water can enter the garage, it may leak into the shelter. Many companies install these garage shelters just slightly above the garage floor to reduce this risk.
- Maintenance: Generally requires more maintenance to prevent corrosion and to ensure the rolling/sliding door operates properly.
Above Ground Shelters
These shelters are typically installed in a garage, basement, indoor living space (closet, pantry, etc.), or outdoors on a concrete slab. They are typically built from steel or reinforced concrete and are securely anchored to the concrete slab.
Pros:
- Accessibility: Easy to access, which is crucial for people in a wheelchair or with mobility challenges.
- Installation Complexity: Typically easier to install since they don’t require extensive excavation.
- Location Flexibility: This type can be installed in garages, basements, or even within the home (pantry, closet, etc.), giving more placement options.
- Portability: If you decide to move, you can relocate the shelter. However, it may be cost-prohibitive to do so.
Cons:
- Aesthetics: More conspicuous and can impact the aesthetics of the property.
- Footprint: Utilizes valuable storage or living space.
- Temperature: Depending on the season and construction material, these shelters could get much warmer or cooler than below-ground shelters. Optional cooling and heating accessories can make these shelters comfortable year-round.
- Access Hazard: If installed on a concrete slab in the yard (vs. in a garage, basement, or other indoor space), it may require going outside in a storm with dangerous hail, lightening and flying debris to gain access, which puts you and your family at risk when seeking shelter.
Conclusion
No one home storm shelter is perfect for all situations. Accessibility needs, budget, available space, site-specific conditions, and personal preferences are all important factors when selecting a storm shelter for your home.
So, which is the safest type of home storm shelter? Below-ground and above-ground shelters both offer excellent protection if they meet FEMA guidelines and ICC standards. Weigh the pros and cons to determine which shelter type best meets your needs. Whichever shelter type you select, you can feel confident in your decision.
What additional pros or cons should be on this list? Let’s discuss in the comments below. Or, contact me directly.