By Craig A. Shutt
Florida's recent series of hurricanes has focused the attention of building and code officials on demands to upgrade homes to better withstand extreme weather. As part of that concern, many states, particularly those with jurisdictions over coastal areas, now require window products to be tested, rated and labeled to document their suitability for use in high-wind areas. As a result, selecting the proper window is as easy as reading a label.
Mike Fischer, director of codes and regulatory compliance for the Window & Door Manufacturers Association, explains that there are several points of consideration for rating windows:
- The key change in building codes for high-wind areas is higher design-pressure ratings, which express the amount of wind pressure a window can withstand when closed or locked.
- The requirements also document great ability to prevent water penetration and air infiltration.
- Also considered is the ability to withstand windborne debris, such as the impact of large "missiles"—2x4s and tree limbs, for example—that can become airborne in a tornado or hurricane.
Tested and labeled
The new requirements are part of the International Building Code (IBC) and International Residential Code (IRC), which are the basis of most updates now being made to older existing code provisions. The changes mostly affect coastal regions. Virtually every municipality, if not state, along the eastern seaboard and Gulf Coast are looking to update their codes if they haven't already. "Contractors and manufacturers are definitely finding that requirements are now more stringent, particularly in communities where codes had been outdated," Mike says.
Many localities accept only products tested by an approved labeling authority, typically WDMA, the American Architectural Manufacturers Association or the National Accreditation & Management Institute.
"As contractors become more experienced using design-pressure ratings, they will learn where to find the products they need and which products meet the requirements," says Paul Bove, PhD, PE, staff engineer in the Inspection Division of the Texas Department of Insurance. Paul helped update the codes in Texas and has produced educational programs to ensure builders and remodelers in that state understand how to read the labels and which products can be used in which areas.
Contractors must be careful that they are using the proper rating for their locations, Paul notes. In areas that regularly have updated and maintained tighter standards, the wind-load changes do not involve significant alterations to local codes. Where code updates have been infrequent, however, the changes could be significant.
Manufacturers stress that window products are readily available for every region and label requirement. Florida was the first state to require higher window standards, and manufacturers responded quickly. Those designs now are becoming more popular in other areas. Labeling ensures that the builder or remodeler can be assured they are using a product that is appropriate for the level of risk in their location.
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