Building Management Hawaii - June/July 2012 - (Page 6)
Saving your structure with hurricane windows.
By Shawn Moseley
t’s hard to believe that Hawaii could ever be hit by another hurricane, especially by one with the size and magnitude of, say, Iniki—a hurricane the set records with winds of 140 miles per hour, $2 billion in damage and six lives lost. And since we’ve had 20 lucky years since then, many people haven’t experienced a hurricane in Hawaii in their lifetime. However, for us older, long-time residents who have witnessed the devastation … we will never forget it. In the 2000s, the Hawaiian Islands were brushed by nine hurricanes. And the statistics suggest that our luck may run out soon. More hurricanes are likely for Hawaii, according to the International Pacific Research Center, University of Hawaii at Manoa. A global atmospheric model predicts that continued global warming will shift the location of tropical cyclones from the western Pacific to the central Pacific (that would be us). These statistics and forecasts have been driving the state and federal governments to update local building codes to include hurricane requirements. Several of the requirements focus on windows because they can save the structural
shell of a building. Once wind enters a building, it becomes much more likely that the structure will be significantly damaged. A window’s performance and its ability to stay shut and airtight are critical during a storm. Hurricanerated windows should also be designed to withstand positive and negative wind pressures. If the window gets sucked out or blown out, the building and its inhabitants are at great risk. When considering hurricane windows for your building, there are a couple of critical things you need to be aware of: There are two types of window requirements—small missile and large missile level D. • Small-missile products are designed for the building’s upper floors. At these heights, the main concern is debris that comes off the rooftops of neighboring buildings and other small items that could fly at the windows. A product is declared small-missile resistant after it has been exposed to various impacts with 10 ball bearings
traveling at a speed of 90 mph. The product is then subjected to wind loads for 9,000 cycles. • Large-missile window products are designed for the lower floors of a building, where there is a great risk of large objects like trees, grills, chairs, tables, etc. to be thrown at them. The current gold-standard in testing is the large missile level D (aka Miami-Dade County hurricane impact test). A window passes muster after it has been exposed to various impacts with a 9-pound piece of lumber, measuring 2” x 4” x 6’ in size, traveling at a speed of 90 mph). Then the product must pass positive and negative wind loads for 9,000 cycles. Now, when you retrofit your windows with hurricane products, it’s important to verify that the existing windows frames can handle the performance of the new product. For example, we don’t recommend that older jalousie frames be retrofitted with new hurricane products, because if that window got hit during a hurricane it’s
Table of Contents for the Digital Edition of Building Management Hawaii - June/July 2012
When the Winds Blow
Why Waterproof? Keep your building watertight & upright.
Get Watertight Water is the greatest solvent in the world ... keep your building dry.
What Drains Your Building?
Asbestos Exposed How to safely recover from mold and flood damage.
Water Leaks—from Bad to Worse
The Power of Paint
Life of Paint
It’s Best to Test A paint test can detect lead, and be the trick in finding a paint that will stick.
Movers & Shakers
Resource Guide: Waterproofing & Painting
Building Management Hawaii - June/July 2012