If you sell products into North Carolina you should know that a Windborne Debris interpretation was issued recently by the North Carolina Department of Insurance.
According to the interpretation, windborne debris protection is required for replacement windows in exterior walls of structures located in the windborne debris region as defined in NC building Code, Section 1609.2 and NC Residential Code, Section 202, in certain situations:
a) Replacing only a glazing panel and not an entire window in a double hung or casement type unit:
No, unless the existing window is designed for windborne debris protection in which case the replacement panel is required to provide windborne debris protection. The glazing panel is considered repair and can be repaired with a like material.
b) Replacing only a window sash and not an entire window:
No, unless the existing window is designed for windborne debris protection in which case the replacement sash is required to provide windborne debris protection. The sash is considered repair and can be repaired with a like material.
c) Replacing a window but not removing the existing window frame:
Yes. The window unit is considered new construction and must meet the requirements for new construction.
d) Replacing a window and the existing window frame:
Yes. The window unit is considered new construction and must meet the requirements for new construction.
e) Replacing a store front glazing panel in an existing window frame:
Yes. The glazing panel is considered new construction and must meet the requirements for new construction.
Additional information, including illustrations for requirements regarding windborne debris protection, is available by viewing previous interpretations posted on the NCDOI website.
The effective date for the North Carolina codes is September 1, 2011, with a mandatory effective date of March 1, 2012.
The American Architectural Manufacturers Association sent out an alert to its Southeast members regarding the clarification and members with additional questions were instructed to contact the association.
Dwight Wilkes, AAMA's Southeast codes consultant, told USGNN.com™ that the interpretation provides valuable information.
"It is a good document and when any enforcement agency says this is what you have to do when you have to do it, that helps clarify the code," he says.
As far as permits Wilkes says it is always important to check with local jurisdictions before beginning work.
"A lot of states will adopt a code but not the administrative section. It does get very complex and my heart goes out to manufacturers that deal in multiple jurisdictions," he says.
"Following the above clarifications is not a problem," comments Thomas Sauers, vice president of sales for Wind-Tech Products in Cross Hill, S.C. However, he adds, "I do question the understanding of the recipient of the upgrade to the storefront mentioned in point E. When replacing storefront glass with impact-rated glass, there may be difficulties with the glazing bead/legs (because impact glass is thicker) and the existing anchorage. This is my point: just because an existing storefront not designed for impact glass receives an impact glass replacement, this does not make the installation an impact-rated installation. Typically an installation meeting impact requires an increase in the anchorage pattern and a stronger anchor than used in typical construction. Impact-rated designs also allow for increased frame coverage on the glass (bite) and the existing frame does not provide this. Bottom line is, the replacement is better, but not an impact-rated package."
