Tag Archives: tornado shelter door failure

“If you are not underground you will not survive!”

As storm shelter designers we constantly hear the statement made that “You cannot survive an EF4 or EF5 tornado unless you are underground”. This information couldn’t be further from the truth. We now know there are codes in place to assist designers and engineers in designing above ground shelters that will withstand an EF5 tornado and provide near-absolute protection to those seeking refuge during the storm.

There have been several above ground shelters in the past few years which have performed quite well in tornados in Oklahoma. To my knowledge there has only been one fatality in an above ground shelter that was constructed per the FEMA P-320 EXCEPT it was found to have had a non-tested door assembly installed. (Reference Schultz Squared Architects’ earlier blog for this information.)

While there is nothing wrong with the idea of being underground in the event of the tornado, I would like to point out some of the potential, problems with underground shelters.

Bobber Effect: This one is pretty scary, and with the large amounts of rain and the ground becoming saturated last summer in Oklahoma there were numerous tornado shelters that actually floated out of the ground just like a fishing bobber in water!
Water infiltration: Whenever a portion of any building is put underground, there is always a potential for ground water to find its way into the building either through surface water or ground water. For obvious reasons the last thing that you need is a tornado shelter that has doubled as an underground swimming pool! Many of the residential underground shelters do not provide waterproofing and/or drainage system around the exterior (similar to a foundation drain around your basement that dumps into your sump) and over time, this could become an issue for you.
Exiting: If you are underground in a debris carrying tornado and it drops your house/building on the door, does anyone know to look for you as you may become trapped for some time before being “dug” out. If that’s the case let’s just hope the torrential rains do not follow the tornado or…see issue number 2.
Accessibility: In a residential shelter stairs are an acceptable method of accessing an underground tornado shelter, for the elderly or physically impaired person whether temporarily or permanently this may not be feasible. In a community shelter wheelchair, accessibility route must be provided along with (2) exits from an underground space, which adds significant cost to the design of the facility.
Ventilation: The building code requires a certain amount of ventilation be provided for both residential and community shelters. Some of that ventilation should be near the floor and some near the roof of the shelter. This is much more difficult to accomplish in a community underground shelter. Another issue regarding ventilation/infiltration are hazardous vapors, anything that is heavier than air will have a tendency to find its way into your underground shelter, i.e. solvents, paint, gasoline, diesel, & kerosene, all of which could be disastrous if it finds its way to a flame source either internal or external to the shelter.

If you decide an underground shelter is right for your building/house do your research and make sure the designer/supplier is reputable and knows how to prevent the issues I have listed above because the tornado is not the only danger that may surround the event. Please don’t misinterpret this blog and believe I am telling you to avoid a well-designed/installed underground shelter as it may be the best place for you to be in a high wind event. Just understand what you are getting yourself into.

Thanks for following, and remember. Ask questions, do your research, and make an informed decision. The lives of you or others may depend on it. Written by Shauna Schultz, AIA

Tornado Shelters – THANK YOU FEMA!

A few weeks ago I wrote about a tornado safe room/shelter door failure that cost an elderly lady in Arkansas her life. This was truly a tragedy. A tragedy that could’ve been avoided through education. FEMA took the initiative to produce an educational document for homeowners regarding tornado safe room/shelter doors. I think it is a really great document that is pretty simple to understand. If you are considering building a shelter or even buying one that is pre-manufactured, this is a must read. I have no doubt if the elderly lady in Arkansas had been aware of this information, she would still be alive today.

This document can be downloaded from the FEMA website at
http://www.fema.gov/media-library/assets/documents/99139

For your convenience, I have also embedded the actual document here.

Read it, think about it, and heed the information. It may save your life or the life of a loved one someday.

Be careful out there!

Written By Corey Schultz, AIA, LEED AP BD+C

Tornado Shelters – Arkansas Tornado Shelter Door Failure

On April 27, 2014, in the state of Arkansas, an EF-4 tornado ravaged the communities of Vilonia and Mayflower killing a total of 12 individuals. One of those deaths, a woman, was killed and her husband seriously injured as they sought refuge in an above ground shelter that the husband had built for the couple’s home. It was a small masonry shelter with a hollow metal door and frame. Unfortunately, the door failed, the woman was killed and her husband seriously injured while the two of them were bracing the door all the while, the rest of the shelter performed the way it was intended. A true tragedy. My heart goes out to the woman and her family. This is not the outcome the couple had planned.

The door and frame were analyzed at Texas Tech University Wind Science Lab in Lubbock, Texas. The goal was to find out why the door failed and the study found just what the problems were with the door system. This is what the study found:

The door and frame were hollow metal with (3) residential grade dead bolts and (3) standard duty hinges.
The frame was not properly anchored to the masonry walls, as a matter of fact, there was no anchorage at all, the cavity of the frame was filled with mortar and the adhesion between the mortar and the masonry was the only thing holding the door in the opening. That is why the couple was attempting to brace the door because it was shaking in the opening.
The door, frame, and hardware were not designed or constructed to withstand tornadic wind forces. The door was apparently struck by a piece of OSB or plywood in the center of the door, bending it and destroying the center dead bolt and the lock set. Further, the top dead bolt failed and the door hinges and hinge screws were also damaged. This all happened almost simultaneously while the couple was pushing against the door.

These three issues lead to this tragedy. Unfortunately, from my understanding, the gentlemen THOUGHT he was being sold a tornado resistant door but in the end that was not the case. Along with the fact that the door was not anchored properly.

As I have said before, the regulations on tornado shelters to date has been minimal. It is like the Wild West out there and the buyer MUST BEWARE!!! Regardless if you’re buying a pre-manufactured shelter/safe room, doing a DIY shelter/safe room, or hiring a design team to design/engineer your shelter/safe room, DO YOUR HOMEWORK! Make sure the proper materials are being purchased/utilized and installed properly. Make sure your designer knows what they are doing. THIS IS AN EXTREMELY COMPLICATED DESIGN/CONSTRUCTION PROBLEM! Not everyone knows how to deal with them and what pitfalls to avoid.

I can tell you right now that one should expect to pay quite a bit more for a tornado resistant engineered/constructed door system than your run of the mill metal door. How much more? Maybe four to six times as much! Why are they so much? Because they are specially designed and constructed for two purposes, 1) to let you in and out of the shelter/safe room, and 2) keep you from perishing in a tornadic even! If you are paying $400 for the door, YOU’VE BOUGHT THE WRONG DOOR! These are not items that you typically find at your local lumber yard. These are special order items. You have to make sure that you are getting and paying for what you need to protect yourself, your family, and friends, whatever the case may be. Because if you stop at the door, you may have just wasted all the rest of the money you put into the shelter/safe room.

The shelter/safe room is only going to be as good as its weakest link. The problem is that weakest link is going to expose itself at the worst possible moment just as it did for the couple in Arkansas. Don’t let the same happen to you.

Be careful out there!

Post by Corey Schultz, AIA, LEED AP BD+C