Volume 12, Issue 7 - September 2011


Special Report —Second in a Series
God Bless Texas

Kiesling and his team set to debunk those myths—and the most immediate goal was to determine “real” wind speeds.
“We concluded that tornado wind speeds are more manageable that we thought,” he says. “We first thought they were in excess of 300 mph but now we know they are in the 200 mph range and we design for 250 mph winds.”

There were other coping strategies being proclaimed that the team had to stop as well.

“Experts were telling people to go to the southwest corner of their house during a tornado and open the windows,” says Kiesling. “That’s certainly not a good strategy.”

At Texas Tech it’s all about helping the building community develop good strategies when it comes to severe wind events such as tornadoes (the center studies hurricanes as well).

The center has individuals such as Larry Tanner, research associate, in the lab testing products and then it has teams of “storm chasers” out in the field testing factors such as atmospheric pressures and wind speeds.

A bulk of the university’s research efforts have revolved around the development of safe rooms and even a standard for their construction. Research performed at Texas Tech University led to the prescriptive shelter designs for the Federal Emergency Management Agency’s (FEMA) booklet, FEMA 320, Taking Shelter from the Storm: Building a Safe Room for your Home or Small Business.

"If we could get people to build a little above code—that happened after Hurricane Andrew—that would go a long way in reducing damage."
—Ernst Kiesling

On the MAT
While Kiesling devotes much of his time to research involving storm shelters (he also serves as executive director of the National Storm Shelter Association), he’s not the only one there concerned with saving lives.

“Some in the industry may not like me,” says Tanner. “I’m not here to make companies money—I’m here to improve life safety.”

When Tanner isn’t in the lab testing products simulated during tornado conditions, he’s traveling to storm sites to assess damage.

Tanner is part of FEMA’s Mitigation Assessment Team (MAT) and he traveled to Joplin, Mo., and Tuscaloosa, Ala., following the recent EF5 tornadoes—his 15th such trip in the past 13 years. The purpose of the MAT is to report on the damage, determine the reasons why the buildings failed and to develop recommendations that can reduce the damage. Tanner says these assessments do result in positive outcomes.

As a result of the 1999 tornadoes, a standard for commercial-sized shelters was developed, which gave way to FEMA 361. Also after the 1999 storms, Tanner’s MAT team found that garage doors were particularly vulnerable in a tornado. The recommendations made in that report resulted in industry development of wind-resistant overhead doors.

Tanner has assessed doors and windows over the years and his observations may surprise some.

“In all of my investigations regarding windows, I have found that double-glazed windows perform fairly well against moderate impact,” says Tanner, who observed this in many tornadoes including his recent assessment of Joplin and Tuscaloosa. “You may lose the outer pane but the inner pane stays intact—I see a lot of that.”

He does add, however, that impact-resistant windows do offer the best level of protection. (For detailed information on the use of impact-resistant windows during hurricanes, see July-August DWM, page 26.)

Products and Promotion Go Hand in Hand
Tanner even works with door and window manufacturers on development of these products, and says the school’s lab goes a step further than other non-university testing firms. “One of the things they get from us is research and development,” says Tanner. “We help them develop their products,” adding that he has tested products for most of the major manufacturers.

“We know how to build the doors in terms of tornado- and impact resistance,” he says. “We give them advice as to why a particular failure may have occurred.”

Tanner and Kiesling do agree, however, with the assessment of many interviewed for DWM’s first article in its special tornado report (see July-August DWM, page 26), that a home with impact-resistant windows can still be vulnerable if the “connections” in the house are poor.

But they also agree that impact-resistant doors definitely make a difference as most of the damage to homes takes place at the lower wind speeds.

“All these products certainly will be more effective if your house is on the periphery of a tornado,” says Tanner.

“Window and door manufacturers are doing a good job of producing good products,” adds Kiesling. “Manufacturers have responded well.”

That’s not to say there isn’t room for improvement—in product development but also in educating homeowners about these products.

“It appears that homeowner awareness is more keen than in previous years,” says Tanner. “Part of that is because a wider portion of the population have experienced these storms and they resulted in a much larger death toll than in the past.”
However, even after an EF3 tornado ripped through Hot Springs Village, Ark., on April 25, Matthew Burr, door and window buyer for Village Home Center, a full-service lumberyard, told DWM magazine that homeowners still aren’t asking about impact-resistant products.

“I was shocked they haven’t,” says Burr. “I’ve brought it up but no one has been interested.”

“I think part of that is lack of awareness to these type of products,” says Tanner. “Homeowners need to be educated on the type of products available,” adding that FEMA does a lot of education in this area. “It’s unfortunate that people have not taken advantage of the free documents that are out there for the taking,” he adds.

“There certainly is a lack of knowledge,” agrees Kiesling. “The media is critical to changing that and news coverage has helped raise awareness of products that may help in a tornado.”

He recalls a 1997 tornado that struck a subdivision of Jerrell, Texas, and destroyed many of the homes .

“Dateline NBC came in and asked what could have been done to save lives.’ We replied, ‘storm shelters,’ and suddenly that received national attention,” says Kiesling.

Even if awareness grows, though, the Texas Tech researchers say cost will continue to be a factor.

“Code changes are often resisted by builders and consumers,” says Kiesling. “Housing marketability is very sensitive to initial cost. Whatever you do that increase initial cost will be resisted.”

While homeowners may fight the price of impact-resistant products for their homes, less resistance may be encountered when the building structure is a school.

“In schools, improved windows are a sensible solution and many companies are coming out with products for those applications,” he adds.

Changes, No; Enforcement, Yes
If homeowners or building owners in tornado-prone areas don’t want to pay for impact-resistant windows, should the codes require them in their structures?

“The codes will never require impact-resistant products for tornado regions,” says Tanner. “Any region east of the Rocky Mountains is vulnerable and that is just too wide of an area. It is impractical to change the codes from a broad standpoint.”

And the two experts don’t believe codes need to change—there is a bigger problem that has to be addressed.

“There is more of a problem with lack of adherence to existing codes,” says Kiesling, who attributes part of the problem to lack of education on the part of the builder and the code official.

While both agree that adherence to current codes is key they also have higher hopes.

“If we could get people to build a little above code—that happened after Hurricane Andrew—that would go a long way in reducing damage,” says Kiesling.

He refers to it as “code-plus” and says it is catching on in some areas prone to high-wind events.

Other areas with room for improvement include improvements in specific buildings with the objective of life safety.

“For example, in a basketball arena where you have 15,000 people in one place, some code improvements may be made for these types of structures,” says Tanner.

Instead of major widespread code changes, Tanner believes some local jurisdictions can make improvements.

“Wichita, Kan., has a law that new mobile home parks have to have safe rooms. Nationally, or even state-wide, that would not have made sense. But on a municipal level there are things that can be improved with respect to vulnerable areas,” he says.

In 2005, Tanner surveyed tornado damage in Evansville, Ind., in a manufactured housing community, and found that many units were not anchored properly. As a result of that investigation the responsibility of mobile home parks was put in the hands of local officials.

“The work we do bears fruit,” says Tanner. “I am an optimist. Sometimes you have to say something a whole bunch of times. But if it’s a good concept people will buy in.”

Other improvements may be in the works as well.

“I just learned today that the American Society of Civil Engineers is investigating an extreme wind map for tornadoes in ASCE-7,” says Tanner. “They have never done that before and I think that is a good thing.”

But still what to do with existing buildings and how to improve upon their design so they can better withstand a storm will continue to be a challenge for the single-family housing industry.

“It’s a big problem because we don’t replace inventory often and it is very hard to retrofit existing buildings,” says Kiesling.

“The manufactured housing industry has done a good job but it’s harder to make changes in a wide industry like single-family housing.”

If there is a silver lining to the recent storms it is that it has created an awareness and demand for storm shelter and impact-resistant products.

“Unfortunately it subsides pretty quickly,” says Kiesling. “After the storms, we were inundated with calls regarding storm shelters but now it is leveling off.”

Still he and Tanner are confident that changes regarding improved building practices will take place. “But it’s not going to change very quickly,” says Kiesling.

They are doing their part, however, to contribute to a shift in mindset. Tanner serves on many organizations related to the creation of standards, such as ANSI, and encourages others to get involved as well. “If you want change, you better be part of the community that is working for it,” he says.



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