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