Volume 14, Issue 1 - January/February 2013
Hurricane Sandy, described as a once in a lifetime storm, has the construction industry thinking about how this weather event will impact future building.
David Barnes, president of Viwinco, based in Morgantown, Pa., was thinking about it well before Sandy hit. He was concerned about how windows in the possibly affected areas would hold up. Also on his mind, was the fact that Ocean City, Md., had just adopted a proposal that weakened the previously required standard.
After all, he has been concerned about a recent change made to the ASCE 7-10 wind zone map just adopted as part of the 2012 International Building Code (IBC). In the new map, the criteria for the wind-borne debris zone for the Mid-Atlantic coast was dropped down to DP-35. It is up to the states whether or not they adopt the change, but in October 2012, Ocean City, Md., did just that.
“The thought was a hurricane would never hit that part of the U.S.,” says Barnes. “As of November 1 you don’t need hurricane windows in Ocean City. Our thought is Delaware and New Jersey were going to take the same line. [New Jersey makes this decision in February 2013.]”
Prior to Ocean City’s decision Barnes had been educating those involved about the benefits of impact windows.
“I ran a test on impact versus non-impact just to show them how the sash bows in one inch on this test,” he says. “No one cared. They thought I had a vested business interest.”
So when New Jersey officials convene in February, will they reconsider this decision, even though Sandy was a “once in a lifetime” storm?
Only time will tell but Barnes wants those making these decisions to be educated. “I would like these Mid-Atlantic states to realize that these windows should be at least DP-50,” he says.
But what do the experts say? Tim Reinhold, chief engineer for the Insurance Institute for Business and Home Safety (IBHS), explains that the first hurricane maps were adopted in 1998 and never changed through 2005 despite the fact that a considerable amount of research had taken place.
“Several million dollars of research went into developing the simulations done for hurricanes,” he says. “As a result of that when they ran the new models the wind speeds corresponding to probability levels we had been using for design dropped.
“While a quick look at the ASCE 7-10 design wind speed maps indicates that the wind speeds have increased, these are now ‘limit state’ design winds and they have to be multiplied by 0.79 to compare them with the design wind speeds shown in ASCE 7-98 through ASCE 7-10. If you do that, the 150 mph contour in ASCE 7-10 corresponds to the 120 mph contour in ASCE 7-05. Consequently, if we had stayed with 150 mph contour in ASCE 7-10 as the trigger for windborne debris protection, much of the hurricane prone coastline would not have required opening protection. In order to preserve the requirements of opening protection in areas where a Category 3 storm could make direct impact, the threshold for opening protection was reduced from 150 mph to 140 mph-and opening protection is also required within one mile of the coast, where design wind speed is between 130 mph and 140 mph.”
Despite what may happen in the various East Coast states when it comes to code adoptions, many in the industry promote a “code plus” scenario.
“The building code is a bare minimum you can get away with,” says Barnes. “That doesn’t mean we are building great houses.” Thus Barnes and Reinhold, along with others, promote a code plus-type scenario.
“In our fortified program and retrofit programs we recommend that people go beyond code. That’s what our fortified program is for new construction. That is a code plus program if you really want to make a disaster-resistant home,” says Reinhold. “There are discounts available for those who go to the code plus due to the benefits.”
Why not mandate it?
“As soon as you mandate it, then people will come in to fight it,” he says. “So when we created our program we tried to be as prudent as we could without making it so onerous for people to follow.”
Reinhold adds that IBHS is certainly monitoring the effects of Sandy but points out that in many cases windows may have held up well. Barnes also says following the storm, he received “zero complaints with its impact lines.”
“Unless a tree fell on the house, it will be pretty hard to find broken windows,” says Reinhold.
Barnes isn’t the only window company, however, who is in favor of DP-50 products along the coast. Chuck Scalzott, chief operating officer for Vytex Windows in Laurel, Md., owns a home in New Jersey and weighed in with his thoughts following the storm.
“I won't argue that the windows should be at least DP-50 near the coast,” he says. “Unfortunately, if your house is down the street laying on its side with impact windows, they really didn't protect the house from floating away. Windows can only do so much.”
He adds that having an impact window to stop some of the windborne debris isn't a bad idea but in some cases it should be common sense.
“If a manufacturer can't do better than DP-35, they should be out of business,” says Scalzott. —TT