IBC 1609.1.2 - Windborne Debris Regions: When Garage Doors Need Impact Protection

In high-wind regions, airborne debris during a storm can shatter glass and breach building envelopes. IBC 1609.1.2 identifies these windborne debris regions and requires that building openings, including glazed garage doors, have impact-resistant protection.

What this section says

IBC 2024 Section 1609.1.2 defines when windborne debris protection is required and what form it must take.

The section requires impact-resistant coverings or glazing for buildings in windborne debris regions. The trigger criteria include building category (Category III and IV buildings in high-wind areas) and exposure (Exposure C or D).

For garage doors specifically, the section states:

"Garage door glazed opening protection for wind-borne debris shall meet the requirements of an approved impact-resisting standard or ANSI/DASMA 115."

ANSI/DASMA 115 is the garage-door-specific missile impact and cyclic wind pressure test standard. It uses two missile sizes:

• A small missile: a 2-gram steel ball bearing fired at the glazed surface
• A large missile: a 9-pound 2x4 board launched at the door panel

After missile impact, the door is cycled through wind pressure loading. The door must not fail structurally or allow water or debris intrusion beyond defined limits.

The section also includes an exception for glazing located more than 60 feet above grade and more than 30 feet above aggregate-surfaced roofs within 1,500 feet of the building. Such high-elevation glazing may not require impact protection.

When it applies

IBC 1609.1.2 applies in windborne debris regions, which are generally defined as areas with Vult greater than 130 mph (for most buildings) or coastal areas with specific wind speed thresholds. Colorado is not generally considered a windborne debris region under the IBC's geographic criteria, since Colorado wind speeds (115 mph in Denver) fall below the typical threshold.

However, the section is directly relevant to:

• Texas, Florida, and Gulf Coast customers purchasing doors for use in those states
• Any commercial facility in Colorado that is also used as a regional distribution hub for areas that do require impact-rated doors
• Contractors specifying doors for multi-state projects

Front Range practitioners need to know IBC 1609.1.2 exists, understand when it applies, and be able to specify DASMA 115-tested doors when required by project location.

What this means for you

Colorado is generally not a windborne debris region. Denver's 115 mph design wind speed falls below the 130 mph threshold that triggers windborne debris requirements for most IBC occupancy categories. Residential and most commercial buildings in Denver do not need DASMA 115-rated doors.

The DASMA 115 test is a higher standard. A door rated to DASMA 115 has survived missile impact AND cyclic wind loading. This is more rigorous than the DASMA 108 structural test alone.

Glazed panels are the focus. The impact protection requirement in 1609.1.2 applies to glazed openings in garage doors, not to solid steel or insulated steel panels. A solid door without windows is not affected by this section.

Verify project location requirements. For commercial projects in or shipping to wind-prone coastal states, specify DASMA 115-tested glazing. G Brothers can source and supply impact-rated doors for projects requiring IBC 1609.1.2 compliance.

Full text and source

Read IBC 2024 Section 1609.1.2 at https://up.codes/s/protection-from-wind-borne-debris. ANSI/DASMA 115 is available from DASMA at dasma.com.

IBC 1609.1.2 applies to commercial construction in windborne debris regions. Colorado buildings at standard design wind speeds generally do not require windborne debris protection.

Want to put numbers to this? Use the interactive wind load psf / mph converter below, or open the full wind load psf / mph converter with examples and notes.