Too Close for Comfort

Julie Ruth
September 21, 2015
COLUMN : Code Arena | Codes & Standards

About 10 p.m. the evening of June 22, 2015, I learned I was under a tornado warning via both my local news station and a weather alert on my cell phone. The words “tornado warning” mean a tornado has either been spotted or is eminent. Those words, along with the lightning show going on outside my windows, convinced me to seek shelter.

I live in a ranch home over a crawlspace. Not yet being frightened enough to seek shelter in the crawl space, I did the next best thing: I sought shelter in the smallest interior room on the lowest (and only) level of my home. This just happened to be the bathroom off of my laundry room.

Not too long after settling in, my phone rang again. It was a friend from the New Lenox Community Emergency Response Team calling to make sure I was aware that my area was under a tornado warning and that I had sought shelter. My friend told me that a tornado had been spotted in Braidwood, Illinois, about nine miles from where I live, and was headed in the direction opposite from my location.

I assured them I would stay where I was “until the (lightning) show was over.” What neither one of us knew at the time was that the Braidwood tornado was the tail end of an EF3 tornado with 160 mph winds that had first touched ground 16 miles to the east, came within six miles of my home, destroyed 50 homes and damaged another 800, in an area with a population of less than 10,000.

The most amazing part is that, even with all that damage, no one was injured. Due to the storm alarm and alert system that is in place, people were warned. And, perhaps because this community has been hit before, people knew how to respond and did so.

Now there have been those who have remarked, correctly, that my response to significant events is sometimes rather scientific. In this case, while others responded by helping clean up debris and providing food and shelter, my response was to pose the question: are the current code requirements for windows adequate?

Over the next few days, I collected as many stories as I could. I wanted to know where people were when the storm hit, how they responded, their experience, etc. And I wanted to know how the windows held up. Of the homes that were destroyed, was window failure a factor? The answer, as you may suspect, is that in some cases window failure was a factor. In other cases, it wasn’t. From my perspective at least, in far too many instances, the story line included mention of the sound of windows cracking just prior to the roof being lifted off.

Time for a Change?

My next question: should the code requirements for windows in tornado-prone areas be more stringent? Would more stringent requirements for new homes have reduced the number damaged and destroyed in Coal City, Illinois, and elsewhere in the United States, by tornados over the course of the last few months? After all, the median age of homes in Coal City before the tornado was 33 years. Wind load requirements for fenestration have changed dramatically in the past 33 years.

The fact of the matter is, however, that even homes built to the most recent edition of the 2015 International Residential Code would not be required to have windows that had been tested to resist the 160 mph wind speeds that occurred in Coal City on June 22. In fact, throughout the Midwest, as it is throughout most of the United States., the Ultimate Design Wind Speed is 115 mph. This is the wind speed to which products are to be designed not to fail.

Is it time to give some thought to increasing the Design Wind Speed? Perhaps a design wind speed as high as 160 mph throughout the tornado- prone area of the United States is unrealistic. But certainly it should be higher than 115 mph. Fenestration does not always have to be the weakest link in the building envelope, nor should it be.

Code Arena is brought to you by the American Architectural Manufacturers Association.

Code Arena is brought to you by the America Architectural Manufacturers Association. Julie Ruth may be reached through AAMA at 847/303-5664 or via e-mail at julruth@aol.com.