NCDOI OSFM Evaluation · PDF fileDOI File # WP-002-10 (Rev. 2013) Wind-borne Debris...

DOI File # WP-002-10 (Rev. 2013) Wind-borne Debris Protection of 26

NCDOI OSFM Evaluation Services

Scope of DOI White Paper: The Purpose of this document is to provide clarification and suggested best

practices on North Carolina State Code requirements to Code Enforcement Officials (CEO) who are

agents for the Authority Having Jurisdiction (AHJ).

DOI File Number: WP-002-10

Edition Date: June 9, 2010

Revision Date: May 20, 2013

Subject of White Paper: Protection of Exterior Openings in Wind-Borne Debris

Regions

Table of Contents

1.0 Intent…………………………………………………………………………………………………....1

2.0 Scope of the NCRC and the NCBC and Definition of “Wind-Borne Debris Region”………...…….…2

3.0 Why Codes Require Openings in the Exterior Envelope of Buildings to Withstand Hurricane Force

Winds…………………………………………………………………………………………….……3

4.0 Code Options for Protecting Glazing in Exterior Openings Located in a Wind-borne Debris Region...4

5.0 Code Requirements for Impact-Resistant Glazing and for Coverings to Protect Non-Impact-Resistant

Glazing in Windows, Doors, and Garage Doors……………………………………………………...5

6.0 Code Requirements for Wood Structural Panels……………………………………………………….7

7.0 Code Design Requirements for Exterior Window, Door, and Garage Door Assemblies to Resist Wind

Pressure………………………………………………………………………………………………..7

8.0 Basic Description of ASTM E 1886 and ASTM E 1996…………………………….………..…….....8

9.0 NCRC Code Requirements when Replacing Windows in Existing Residential Dwellings Located in a

Wind-Borne Debris Region…………………………………………………………………………...9

10.0 Submittals the Code Enforcement Official may request for Verification of Code Compliance or

Equivalency………………………………………………………………………………………….10

11.0 Maintaining Emergency Escape and Rescue Opening Code Requirements in Wind-borne Debris

Regions………………………………………………………………………………………………12

12.0 Recommendations for Job Site Consideration by the Code Enforcement Official..............................13

13.0 Other Recommendations for Consideration by the Code Enforcement Official……………………..13

14.0 References…………………………………………………………………………………………….14

15.0 Credits for Figures……………………………………………………………………………………14

16.0 Illustrations Attached to this Document……………………………………………………………...15

1.0 Intent

A. The 2012 North Carolina Residential Code (NCRC) and the 2012 North Carolina Building

Code (NCBC) each have similar requirements for protecting openings in the exterior envelope

of a building located in a wind-borne debris region*. The intent is to keep the glazing in these

openings (windows, doors and garage doors) from being breached when impacted by debris

propelled by hurricane-force winds, as well as from the resulting wind pressure to these


opening assemblies.

* Section 2.0 of this document addresses the scope of the NCRC & the NCBC and their

definition of “wind-borne debris region”.

B. Note the following for clarification:

1. Code requirements for impact protection of glazing apply to glass in exterior openings of

buildings that are only located in a wind-borne debris region. Glazing protection is not

required by code in exterior openings located in non-wind-borne debris regions, except as

addressed in Section 2406 of the NCBC.

2. Code requirements for the design pressure rating, often referred to as the “DP” rating”,

of exterior window and door assemblies shall be in accordance with the wind zone of

buildings located throughout the state and not only for buildings located a wind-borne

debris region.

2.0 Scope of the NCRC and the NCBC and Definition of “Wind-Borne Debris Region”

A. NCRC:

1. The scope of the NCRC is addressed in R101.2. This section states this code “shall apply

to the construction, alteration, movement, enlargement, replacement, repair, equipment,

use and occupancy, location, removal and demolition of detached one- and two-family

dwellings and townhouses not more than three stories above grade plane in height with a

separate means of egress and their accessory buildings and structures”.

2. Basic (design) wind speeds for 50 year mean recurrence interval for NC Counties are

determined from the map in Figure R301.2 (4) and interpolation between contours on the

map is not allowed. There is a chart, also identified as “Figure R301.1(4)-continued”,

which specifically lists the design wind speed for each N. C. County.

3. Section R202 of the NCRC defines “wind-borne debris region” as follows:

WIND-BORNE DEBRIS REGION-Areas within hurricane prone regions defined as that

area east of the inland water-way from the North Carolina/South Carolina state line

north to Beaufort Inlet and from that point to include the barrier islands to the North

Carolina/Virginia state line.

B. NCBC:

1. The NCBC is applicable to all structures that are not regulated by the NCRC, as

addressed in Section 101.2 of the NCBC. Note that detached one & two family dwellings

and multiple single family dwellings (townhouses) that are more than three stories above

grade plane in height are classified by occupancy as R-3 and shall comply with the

requirements of the NCBC.

2. The basic wind speed to determine the wind loads for NC Counties is indicated on the

map in Figure 1609 and is in 10 mile per hour increments. Interpolation between contours

on the map is allowed.

3. Section 1609.2 of the NCBC defines “wind-borne debris region” as follows:

WIND-BORNE DEBRIS REGION-Areas within hurricane prone regions defined as that

area east of the Intracoastal water-way from the North Carolina/South Carolina state

line north to Beaufort Inlet and from that point to include the barrier islands to the North

Carolina/Virginia state line.


3.0 Why Codes Require Openings in the Exterior Envelope of Buildings to Withstand Hurricane

Force Winds

A. The NCRC and the NCBC require the structure of a building located in a wind-borne debris

region to withstand sustained hurricane-force winds flowing around and over its exterior

envelope. Each Code also requires the opening assemblies located in the exterior of the

building envelope to withstand the pressures from high winds and the glazing in these

openings to remain in place when subjected to objects propelled by high winds.

B. Depending on the location of opening(s) with respect to wind direction during a hurricane,

breached openings in the exterior envelope can allow strong winds to rush inside the building.

These trapped wind forces can create extremely high internal pressures on the roof, sidewalls

and leeward wall that exceed the resistant limitation of the building’s structural elements to

withstand the total wind pressure. Consequently, the internal pressures can ultimately result in

severe damage to, if not total destruction of, the building. An elementary example of this

effect is to pump air into a tire until the outer surface, at its weakest point, blows out. (See

figure 1)

Figure 1: Effects of internal pressure in the interior of a building from a breached

opening in the exterior envelope during hurricane-force winds

C. The NCBC and the NCRC address protection requirements for glazing and opening

assemblies in the exterior envelope of a building located in a wind-borne debris region:

1. Glazing: In exterior windows, doors, garage doors and similar openings, glazing is

required to be protected from being shattered by wind-borne debris. Note that “wind-

borne debris” can be any object or material that could become an air borne missile

propelled by hurricane-force winds. For example, sustained hurricane-force winds can

dislodge building materials, such as shingles or roofing gravel, or unsecured objects on

the ground, such as trashcans or patio furniture. Thus, these objects can become

“missiles”, which could break out the glass in an exterior opening. Impact resistance is

required only in the wind-borne debris regions defined by the Code, except as addressed

in Section 2406 of the NCBC. See Section 4.0 of this document for code options to

protect glazing in exterior openings.

2. Opening assemblies: When subjected to the forces and pressures of high wind, codes

address the ability for exterior window, door, and garage door assemblies (sashes, frames,

associated fasteners, etc.) to remain in place, i.e., to not be blown in or out. See Section


7.0 of this document for information on code design requirements for window, door, and

garage door assemblies to resist wind pressure.

4.0 Code Options for Protecting Glazing in Exterior Openings Located in a Wind-borne Debris

Region

The NCRC and NCBC require all glazing on the exterior of buildings located in wind-borne debris

regions to be impact resistant or to be protected with an impact-resistant covering. Another option,

which is a prescriptive code method, is to install wood structural panels over non-impact resistant

glazing for protecting the glass from flying debris.

A. Impact-Resistant Glazing: For a new building or an

addition to an existing building located in a wind-borne

debris region, impact-resistant glazing complying with

code is an option to prevent an opening from being

breached by flying debris (See Figure 2). Impact-

resistant glazing is composed of several layers of glass

with a membrane film sandwiched between each layer.

Although flying debris may be able to crack the glass, the

intent is for the lamination to hold the broken layers of

glass together to prevent the missile from penetrating the

building envelope, and thus breaching the exterior

opening. Refer to 5.0 of this document for NCRC and

NCBC requirements for impact-resistant glazing systems.

B. Protective Coverings for Non-Impact-Resistant Glazing: The NCRC and the NCBC have

requirements for impact-resistant coverings to protect non-impact-resistant glazed openings in

the exterior of a new building or an addition to an existing building located in wind-borne a

debris region.

1. Protective coverings can be made of wood, metal (aluminum, galvanized steel, stainless

steel, etc.), fiberglass, flexible fabric/woven mesh screens, polycarbonate, polypropylene,

(or similar plastic paneled systems) and other materials that have been tested to comply

with impact-resistant requirements of the code.

2. Some examples of covers that may provide protection for non-impact resistant glazing

include roll down shutter systems (Figure 3), side-hinged shutters (Figure 4), horizontal

sliding accordion shutter system (Figure 5 on page 5) and Bermuda/Bahamas style

shutters (Figure 6 on page 5).

Figure 1: Impact resistant glass

after being struck by 2 x 4

Figure 3: Example of roll-down shutter at

head of windows.

Figure 4: Example of side-hinged shutters

on each side of window/door.


3. Refer to 5.0 of this document for NCRC and NCBC requirements for coverings to protect

non-impact-resistant glazing.

C. Wood Structural Panels: For a new building or an addition to an existing building located in a

wind-borne debris region, wood structural panels installed over exterior non-impact resistant

glazing is a prescriptive code method for protecting exterior glazed openings from flying

debris. Refer to 6.0 of this document for NCRC and NCBC requirements for wood structural

panels.

5.0 Code Requirements for Impact-Resistant Glazing and for Coverings to Protect Non-Impact-

Resistant Glazing in Windows, Doors, and Garage Doors

A. NCRC (Note-Opening protection of glazing can be achieved with either impact-resistant

glazing or with a protective covering over non-impact-resistant glazing):

1. Sections R301.2.1.2 and R612.9 address the ability of glazing in exterior window and

doors of buildings located in wind borne debris regions to resist shattering from flying

debris during high wind events.

a. Section R612.9 states “Protection for exterior windows and glass doors in buildings

located in wind-borne debris regions shall be in accordance with Section

R301.2.1.2”. R301.2.1.2 is addressed in Section 5.0-A.1.c of this document.

b. Section R612.9.1 “Entitled “Fenestration* Testing and Labeling”): In reference to

wind-borne debris protection, this section states that “Fenestration shall be tested by

an approved independent laboratory, listed by an approved entity, and bear a label

identifying manufacturer, performance characteristics, and approved inspection

agency to indicate compliance with the requirements of the following specification”:

ASTM E 1886 and ASTM E 1996 (see Section 8.0 of this document for

information on ASTM E 1886 and ASTM E 1996); or

AAMA 506 (2006 referenced standard) – Voluntary Specification for Hurricane

Impact and Cyclic Testing of Fenestration Products.

* Definition of FENESTRATION in Section R202 of the NCRC: Skylights, roof

windows, vertical windows (whether fixed or moveable); opaque doors; glazed

Figure 5: Example of horizontal sliding accordian

shutter system in the opened and in the closed positions.

Figure 6: Example of Bahamas

/Bermuda style shutters in the

opened and in the closed positions.


doors; glass block; and combination opaque/glazed doors.

c. Section R301.2.1.2: This Section requires the glazing in the openings in the exterior

envelope of a building located in a wind-borne debris region to resist breakage by

flying debris. The code allows glass in the opening to be impact-resistant glazing or

non-impact-resistant that is protected by a covering. Both impact resistant glazing

and coverings protecting non-impact resistant glazing shall meet the requirements of

the Large Missile Test of ASTM E 1996 (2006 referenced standard) and ASTM E

1886 (2006 referenced standard).

2. Glazed openings in garage doors: Section R301.2.1.2 addresses protection of garage

doors glazed openings in exterior walls of buildings located in a wind-borne debris

region. This Section requires glazed protection to meet the requirements of an approved

impact-resisting standard (by the CEO/AHJ) or ANSI/DASMA 115 (2005 referenced

standard). Note that ANSI/DASMA 115 is the “Standard Method for Testing Garage

Doors: Determination of Structural Performance under Missile Impact and Cyclic Wind

Pressure”.

B. NCBC (Note-Opening protection can be achieved with either impact-resistant glazing or with

a protective covering over non-impact-resistant glazing*):

1. Section 1609.1.2 addresses the protection of glazing in exterior window and doors located

in wind borne debris regions from flying debris. This Section states “glazing in buildings

shall be impact resistant or protected with an impact-resistant covering meeting the

requirements of an approved impact-resistant standard (by the CEO/AHJ) or ASTM E

1996 (2005 standard) and ASTM E 1886 referenced herein as follows” (see Section 8.0 of

this document for information on ASTM E 1886 and ASTM E 1996):

a. “Glazed openings located within 30 feet of grade shall meet the requirements of the

large missile test of ASTM E 1996.”

b. “Glazed openings located more than 30 feet above grade shall meet the provisions of

the small missile test of ASTM E 1996.”

* Note: Attachments of the impact-resistant glazing to the window frame and the

attachment of the window frame to the building structure as well as the attachment of

impact-resistant coverings to protect non-impact-resistant glazing shall be designed

to resist component and cladding wind pressures as determined in accordance with

the provisions of Minimum Design Loads for Buildings and Other Structures in

ASCE 7 (2005 reference standard). The intent is for the design pressure rating on the

opening component label to equal or exceed the required design pressure calculated

using ASCE-7.

2. Exceptions in Section 1609.1.2 where glazed openings of buildings located in wind borne

debris regions are not required to be protected:

a. Exception # 2 states “Glazing in Occupancy Category I buildings as defined in

Section 1604.5, including greenhouses that are occupied for growing plants on a

production or research basis, without public access shall be permitted to be

unprotected”.

b. Exception # 3 states “Glazing in Occupancy Category II, III or IV buildings (as

defined in Section 1604.5) located over 60 feet above the ground and over 30 feet

above aggregate surfaced (stone ballast or gravel) roofs located within 1,500 feet

(horizontally) of the building shall be permitted to be unprotected.” However, note

that conversely, glazing in Occupancy Category II, III or IV buildings located less


than 30 feet above aggregate surfaced (stone ballast or gravel) roofs located within

1,500 feet (horizontally) of the building shall be protected. Protection of glazing for

these openings shall meet the requirements of the Small Missile Test of ASTM E

1996. For additional information, also refer to Drawings 1, 2 & 4 in Attachment B of

this document under “16.0-Illustations”.

3. Glazed openings in garage doors: Section 1609.1.2.2 addresses protection of garage doors

glazed openings in exterior walls of buildings located in a wind-borne debris region. This

Section requires protection to meet the requirements of an approved impact-resisting

standard (by the CEO/AHJ) or ANSI/DASMA 115 (2005 referenced standard) which is

the “Standard Method for Testing Garage Doors: Determination of Structural

Performance under Missile Impact and Cyclic Wind Pressure”.

6.0 Code Requirements for Wood Structural Panels Used as Wind Borne Debris Protection

A. NCRC: “Exception” under R301.2.1.2 and accompanying Table R301.2.1.2 addresses

prescriptive code requirements for wood structural panels. Refer to Drawings 1-6 in

Attachment A of this document under “16.0-Illustations” that also includes information on

wood structural panel requirements by the NCRC.

B. NCBC: Exception #1 under 1609.1.2 addresses prescriptive code requirements for wood

structural panels. Refer to Drawings 3 & 4 in Attachment B of this document under “16.0-

Illustations” that also includes information on wood structural panel requirements by the

NCBC.

7.0 Code Design Requirements for Exterior Window, Door, and Garage Door Assemblies for

Resisting Wind Pressure

A. NCRC:

1. Section R301.2.1 addresses wind load requirements in designing a lateral-force-resisting

system for a building. This Section also states “Where loads for curtain walls, exterior

windows, skylights, garage doors and exterior doors are not otherwise specified, the

loads listed in Table R301.2(2) adjusted for height and exposure using Table R301.2(3)

shall be used to determine design load performance requirements for curtain walls,

exterior windows, skylights, garage doors and exterior doors”.

2. Exterior Window and Door Assemblies

a. Section R612.5: This section addresses the performance of exterior windows and

door assemblies in any wind zone. It reiterates Section R301.2.1 by restating that

these openings “shall be designed to resist the design wind loads specified in Table

R301.2.(2), adjusted for height and exposure per Table R301.2.(3)”*. Table

R301.2(4) tabulates the required design pressures, adjusted for height, for

fenestration located in 90 and 100 mph wind zones. Pressures in this table are for

Exposure Category B. The design pressure rating on the window or door label must

exceed the adjusted pressure from Table R301.2(3) or the pressure from Table

R301.2(4). The design and anchorage requirements, when located in the building

envelope (referenced as “main force-resisting system”), are addressed in Section

R612.10. These sections of the code ensure the window or door and its anchorage

have the structural integrity to sustain static pressures imparted by the wind and do

not address impact-resistance.

* Note: Chapter 45, entitled “High Wind Zone”, is a North Carolina addition to the


IBC. Based on Table R301.2.(2), Table R4502(a) lists the required design pressures

for windows and doors in wind zones from 110 mph to 130 mph and includes the

adjustment for height and exposure per Table R301.2.(3)”.

b. Section R612.6 addresses testing and labeling of exterior windows and sliding doors:

This Section states that these opening elements shall be “tested by an approved

independent laboratory, and bear a label identifying manufacturer, performance

characteristics and approved inspection agency to indicate compliance with

AAMA/WDMA/CSA 101/I.S.2/A440. Exterior side-hinged doors shall be tested

and labeled as conforming to AAMA/WDMA/CSA 101/I.S.2/A440 or comply with

Section R612.8”.

Section R612.8 is an exception to Section R612.6 for exterior windows and door

assemblies not included within the scope of Section R612.6. An example is a

custom window or door which is not a manufactured “off the shelf” item.

Section R612.8 allows these windows and doors to be tested in accordance with

ASTM E 330 (2002 referenced standard) as an alternate test standard which

requires testing to 1.5 times the required design pressure. Note that glass in

assemblies covered by this exception shall comply with Section R308.5 which

states “site built windows shall comply with Section 2404 of the International

Building Code”, i.e. the NCBC.

3. Overhead garage doors:

a. As addressed in Section R301.2.1, the

loads listed in Table R301.2(2) that

are adjusted for height and exposure

using Table R301.2(3) or Table

R301.2(4), shall be used to determine

design load performance requirements

for garage doors. (Note: Chapter 45,

entitled “High Wind Zone”, is a North

Carolina addition to the IBC. Based

on Table R301.2.(2), Table R4502(b)

lists the required design pressures for

garage doors and includes the adjusted

for height and exposure per Table

R301.2.(3)”.)

b. Section R612.7 states “Vehicular access doors shall be tested in accordance with

either ASTM E 330 or ANSI/DASMA 108, and shall meet the acceptance criteria of

ANSI/DASMA 108”. Section R612.8 allows these garage doors to be tested in

accordance with ASTM E 330 (2002 referenced standard) as an alternate test

standard which requires testing to 1.5 times the required design pressure.

c. Figure 7 is an example of a garage door blown inward from hurricane-force winds.

B. NCBC:

1. Section 1405.13 states “Windows and doors installed in exterior walls shall conform to

the testing and performance requirements of Section 1715.5”. Section 1405.13.1 requires

windows and doors to be installed in accordance with approved manufacturer’s

instructions, including fastener size and spacing and calculations based on maximum

loads and spacing used in the tests.

Figure 7: Garage door blown inward

from hurricane–force winds.


2. Section 1715.5 permits two methods for testing wind loading for exterior window and

door assemblies. The design pressure rating of these assemblies in buildings shall be

determined in accordance with Section 1715.5.1 or with Section 1715.5.2 for any wind

zone.

a. Section 1715.5.1 states, “Exterior windows and sliding doors shall be tested and

labeled as conforming to AAMA/WDMA/CSA101/I.S.2/A440. The label shall state

the name of the manufacturer, the approved labeling agency and the product

designation as specified in AAMA/WDMA/CSA101/I.S.2/A440. Exterior side-

hinged doors shall be tested and labeled as conforming to

AAMA/WDMA/CSA101/I.S.2/A440 or comply with Section 1715.5.2. Products

tested and labeled as conforming to AAMA/WDMA/CSA 101/I.S.2/A440 shall not

be subject to the requirements of Sections 2403.2 and 2403.3.Exterior side-hinged

doors shall be tested and labeled as conforming to

AAMA/WDMA/CSA101/I.S.2/A440 or comply with Section 1715.5.2”.

b. Section 1715.5.2, as an alternate to Section to 1715.5.1, states that Exterior windows

and door assemblies (not provided for in Section 1715.5.1) “shall be tested in

accordance with ASTM E 330. Exterior window and door assemblies containing

glass shall comply with Section 2403. The design pressure for testing shall be

calculated in accordance with Chapter 16. Each assembly shall be tested for 10

seconds at a load equal to 1.5 times the design pressure”.

3. Structural performance (pressure testing) of garage doors shall be determined in

accordance with either ASTM E 330 or ANSI/DASMA 108, and shall meet the

acceptance criteria of ANSI/DASMA 108.

8.0 Basic Description of ASTM E 1886 and ASTM E 1996

A. ASTM E 1886 (Note: The 2005 edition is referenced in Chapter 35 of the NCBC and the 2006

edition is referenced in Chapter 44 of the NCRC) - Standard Test Method for Performance of

Exterior Windows, Curtain Walls, Doors and Storm Shutters Impacted by Missile(s) and

Exposed to Cyclic Pressure Differentials.

1. ASTM E 1886 specifies the requirements for performing the missile tests. “Scope” under

1.1 of ASTM E 1886 states “This test method determines the performance of exterior

windows, curtain walls, doors, and impact protective systems impacted by missile(s) and

subsequently subjected to cyclic static pressure differentials”. The scope continues with

“This test method is applicable to the design of entire fenestration or impact protection

systems assemblies and their installation. The performance determined by this test

method relates to the ability of elements of the building envelope to remain un-breached

during a windstorm”.

2. The NCBC requires compliance with the large and possibly the small missile test of

ASTM E 1886, based on the height of the glazed opening above grade. For additional

information in this document, refer to Drawings 1, 2 & 4 under “16.0 Illustrations

Attached to this Document”. ASTM E 1886 specifies a small and a large missile used in

the test as follows:

a. Section 6.2.7.1 in ASTM E 1886 describes the physical characteristics of the small

missile used in the test as a solid steel ball. The ball must be within a specified

tolerance range for mass (weight) and diameter. The test is conducted at an impact

speed between 0.40 and 0.85 of the basic wind speed (3-second wind gust in

accordance with ANSI/ASCE 7).


b. Section 6.2.7.2 in ASTM E 1886 describes the physical characteristics of the large

missile used in the test as a No. 2 or better Southern Yellow Pine or Douglas Fir 2 X

4 dimension lumber having an American Lumber Standard Committee accredited

agency mark. The lumber must be within a specified tolerance range for mass

(weight) and length with no defects (knots, splits, etc.) within 12” of the impact end.

The test is conducted at an impact speed between 0.10 and 0.55 of the basic wind

speed (3-second wind gust in accordance with ANSI/ASCE 7).

c. Section 6.2.7.3 in ASTM E 1886 permits other types of missiles to be used in the test.

This section states “Any other representative missile with mass, size, shape, and

impact speed as a function of basic wind speed determined by engineering analysis”.

B. ASTM E 1996 (2006 referenced standard) - Standard Specification for Performance of

Exterior Windows, Curtain Walls, Doors and Storm Shutters Impacted by Windborne Debris

in Hurricanes

1. This standard establishes a uniform set of specifications and performance guidelines

required to conduct Test Method E 1886.

2. The intent of this specification, as stated in Section 1.3 under scope, is to provide “a basis

for judgment if the ability of the applicable elements of the building envelope to remain

un-breached during a hurricane, thereby minimizing the damaging effects of hurricanes

on the building interior and reducing the magnitude of internal pressurization”.

9.0 NCRC Code Requirements when Replacing Windows in Existing Residential Dwellings

Located in a Wind-Borne Debris Region

A. Repairing or replacing a non-protected window opening(s) in an existing dwelling located in a

wind-borne debris region may trigger the requirement for the new window opening(s) in the

existing openings to comply with current code for protection from flying debris. For

information on this topic, refer to the NCDOI-OSFM Website at www.ncdoi.com/osfm :

At the NC Department of Insurance, Office of State Fire Marshal Website, click on

“Engineering and Codes” where a menu will “drop down”;

On this menu click on “Code Enforcement Resources”, after which a new screen will

appear;

Click on “Code Interpretations” from the directory on the left hand side of this screen and

a list of the types of states codes will appear on the right hand side of this screen;

On the line entitled “Residential”, click on “2012” which is on the same line at the far

right;

This directs you to the “2012 Residential” site where you click on the document entitled

“R301.2.1.2 – Windborne Debris Protection”. This document is dated December 18, 2012.

B. Where the NCDOI OSFM Website Document entitled “R301.2.1.2 – Windborne Debris

Protection” (dated December 18, 2012) triggers the requirement for wind-borne debris

protection, note that a building permit, issued by the AHJ, is required before this work can

commence.

10.0 Submittals the Code Enforcement Official may request for Verification of Code Compliance

or Equivalency

At their discretion, the following is suggested information the code enforcement official/authority

having jurisdiction may request to confirm code compliance:

A. Submission may include a copy of the following:

http://www.ncdoi.com/osfm


1. Copy of ASTM E 1886:

a. 2005 referenced standard for compliance with the NCRC; or

b. 2006 referenced standard for compliance with the NCBC.

2. Copy of ASTM E 1996 (2006 referenced standard), Large Missile Test and/or Small

Missile Test, as appropriate for the NCRC or the NCBC.

B. Submission may include a copy of the Test Report from an independent third party testing

laboratory certifying that the protective covering complies with ASTM E 1886 and ASTM E

1996:

1. The laboratory shall be accredited (for the specific test method under consideration) by

the International Accreditation Service, Inc. (IAS) or an accreditation service recognized

by IAS. Website for link to list of IAS accredited test laboratories is

http://www.iasonline.org/More/search.html.

2. Copy of the test report, to include information listed under Item 12 of ASTM E 1886.

3. Impact-resistant coverings shall be tested as an assembly. The assembly shall include the

material, frame (if a part of the system), attachment hardware/anchors, & all associated

components normally used for product installation as defined by the manufacturer or as

required for a specific project.

4. The test report for compliance with ASTM E 1886 shall include the basic wind speed

under which the product was evaluated.

5. For protective coverings such as flexible fabric/woven mesh screens that deflect on

impact from wind-borne debris, the test report for compliance with ASTM E 1886 shall

indicate minimum clear dimension required between the protective covering and the

glazing.

C. For work being performed under the NCBC, the submission may include written confirmation

from the applicant to the AHJ that there is, or is not, an aggregate surfaced roof within 1500

feet of the project, as addressed in Exception # 3 under Section 1609.1.2 of the NCBC.

D. At the discretion of the CEO/AHJ, the submission may include a Shop Drawing from the

product manufacturer that should contain the following information:

1. Maximum width and height of single opening for which the covering assembly has been

tested for compliance with ASTM E 1886 & ASTM E 1996 may be requested with the

manufacturer’s requirements for the conditions of the project.

2. Provide details of manufacturer’s anchorage requirements for the type of substrate

(concrete, masonry, wood framing/studs, aluminum, etc.) on which the covering will be

secured. Include description/specification of type of fasteners for each substrate material,

maximum spacing of fasteners and minimum embedment/penetration depth of fasteners

into each type of substructure.

3. Each sheet of shop drawings shall be sealed by a design professional, registered in North

Carolina.

4. Exception under Section R301.2.1.2 of the NCRC addresses structural wood panels with

the requirement that permanent attachment hardware is to be “corrosion-resistant”.

a. For protective coverings to properly function when needed, recommendation is that

all permanent components, including attachments, anchors, fasteners, etc. are to be

corrosion-resistant. (Note-“corrosion-resistant” is not defined in the codes. However,

http://www.iasonline.org/More/search.html.


the American Iron and Steel Institute (AISI) states corrosion-resistant “is a material's

ability to resist deterioration caused by exposure to an environment”.

b. Materials (usually metals) deteriorate at different rates. For example, a stainless steel

alloy will resist corrosion for a longer time period than hot-dipped galvanized steel.

Also note that plastic based materials can become brittle in a harsh coastal

environment. It is important for a fastener or other part of an opening protective to

be replaced when it corrodes or deteriorates to the degree that it can no longer serve

the function for which it was intended.

E. If the covering protecting the non-impact-resistant glazing deflects inward towards the glazing

upon impact, the minimum separation distance required between covering and glazing by the

manufacturer should be provided. An example is a flexible fabric protective covering.

F. Submission may include a copy of the manufacturer’s printed installation instructions.

G. Submission may include written verification from contractor/installer that the substrate for

attaching the protective covering is a solid and an acceptable substrate, capable of

accommodating the attachments/fasteners to sustain the loads as required by Code.

H. The Code Enforcement Official may require a sample of the proposed product/covering,

including proposed anchorage, be included as a part of the submission for review and approval

of the work. (After approval, the CEO can return the sample to the applicant for incorporation

into the project.)

11.0 Maintaining Emergency Escape and Rescue Opening Code Requirements in Wind-borne

Debris Regions

In addition to providing natural lighting and ventilation, operable windows can also serve as a

means for a building occupant to escape or to be rescued by emergency responders during a

building fire or similar life-threating event. An exterior opening required by code to serve as an

emergency escape and rescue opening can be located in a wind-borne debris region and also

required by code to be protected from hurricane force winds. After a high wind event has passed

and opening protection is no longer necessary, the opening protective shall be removed before the

space is reoccupied if the protective covering prevents the ability of an opening to serve as a code

required means of escape and rescue.

A. NCRC - Section R310 addresses emergency escape and rescue exterior opening requirements

by the Residential Code. Section R310.1 describes the location where the opening

requirements apply.

1. Where Section R310.1 requires an exterior glazed opening to serve as a means of

emergency escape and rescue and Section R301.2.1.2 requires the same opening to have

protection from wind-borne debris, recommendation is for the submission to include:

a. From the Designer or Contractor where a protective covering(s) is to be left

permanently in place at an exterior glazed opening(s), written confirmation that the

protective covering also complies with Section R310.4. Section R310.4 requires an

opening to be releasable or removable from the inside of the room without the use of

a key, tool, special knowledge or force greater than that which is required for normal

operation of the escape and rescue opening and this should also apply to the

permanently installed protective covering. Further, the permanently installed

protective covering, when in the opened position, shall not restrict or hinder the

ability of the glazed opening to serve as an operable emergency escape and rescue

opening, as required by Section R310.2; or


b. From the Building Owner where the protective covering is not to be left permanently

in place at an exterior glazed opening(s), written confirmation that the protective

covering shall be removed from the exterior glazed opening(s) after wind-borne

debris protection is no longer required before the room is reoccupied (for compliance

with Section R310). An example is wood structural panels screw attached from the

exterior.

B. NCBC - Requirements for Emergency Escape and Rescue:

1. Section 1029 addresses emergency escape and rescue opening requirements. Section

1029.1 describes the occupancy groups, room types and other areas where the opening

requirements apply, unless exempted by one of the Exceptions listed under Section

1029.1.

2. Where Section 1029.1 requires an exterior glazed opening to serve as a means of

emergency escape and rescue and Section 1609.1 requires the same opening(s) to have

protection from wind-borne debris, recommendation is for the submission to include the

following:

a. From the Designer or Contractor: Where a protective covering(s) is to be left


protective covering also complies with Section 1029.4. Section 1026.4 requires an

opening cover to be releasable or removable from the inside (of the room) without

the use of a key, tool, special knowledge or force greater than that which is required

for normal operation of the escape and rescue opening. Further, the permanently

installed protective covering shall not restrict or hinder the ability of the glazed

opening to serve as an operable emergency escape and rescue opening, as required by

Section 1029.1; or

b. From the Building Owner: Where the protective covering is not to be left


protective covering shall be removed from the exterior glazed opening(s) after wind-

borne debris protection is no longer required before the room is reoccupied (for

compliance with Section 1029). An example is wood structural panels screw attached

from the exterior.

12.0 Recommendations for Job Site Consideration by the Code Enforcement Official

A. The Code Enforcement Official may require a copy of the manufacturer’s printed installation

instructions and, if applicable, approved shop drawings to be kept at the job site during

construction until certificate of occupancy for the project is issued by the CEO/AHJ.

B. The Code Enforcement Official may require all protective coverings to be marked with a

label, indicating the manufacturer’s name, product name and/or model number, size and

compliance with ASTM E 1886 and/or ASTM E 1996 and applicable reference standard under

which it was tested. Recommendation also is for the third party testing to be identified on the

label. If any labels are temporarily affixed to the product, no label should be removed until the

Code Enforcement Official approves the installation of the product.

C. If the protective coverings are not designed to remain in place permanently at the opening, the

Code Enforcement Official may require that one of each type of protective covering is be left

in place over an opening at the time the Code Enforcement Official visits the site to inspect

the installation. The Code Enforcement Official should have access to all stored protective

coverings.


13.0 Other Recommendations for Consideration by the Code Enforcement Official

A. The Code Enforcement Official may require verification that the installer is certified by the

manufacturer to install their product, if the manufacturer has such a program.

B. For protective covering systems not permanently mounted and designed to be removed when

not in use, the Code Enforcement Official may require that each covering be marked or

labeled in some manner to identify which specific opening the cover is intended to protect on

the structure. This can be of particular importance when the protective coverings are wood

structural panels, as addressed in Section 6.0 of this document.

C. The Code Enforcement Official may require written certification by the installer/contractor

that coverings are installed in accordance with the manufacturer’s printed installation

instructions and, if applicable, the approved shop drawings.

D. If written confirmation is not submitted that there is no aggregate surface roof within 1500

feet of the proposed work, the Code Enforcement Official may require that all glazed opening

protection be designed to comply with Exception # 3 under Section 1609.1.2 of the NC

Building Code, as applicable for the conditions of the project.

14.0 References

1. 2012 North Carolina Residential Code

2. 2012 North Carolina Building Code

3. 2009 International Residential Code and Commentary by the International Code Council,

Inc.

4. 2009 International Building Code and Commentary by the International Code Council,

Inc.

5. ASTM E 1886 - Standard Test Method for Performance of Exterior Windows, Curtain

Walls, Doors and Storm Shutters Impacted by Missile(s) and Exposed to Cyclic Pressure

Differentials (Note - 2005 edition referenced in Chapter 35 of the NCBC and the 2006

edition referenced in Chapter 44 of the NCRC.)

6. ASTM E 1996 (2006 referenced standard) - Standard Specification for Performance of

Exterior Windows, Curtain Walls, Doors and Storm Shutters Impacted by Windborne

Debris in Hurricanes

7. Hurricane Retrofit Guide by the State of Florida-Division of Emergency-Bureau of

Mitigation

15.0 Credits for Figures

A. Figure 1: 2009 International Building Code Commentary, figure 1609.1.2

B. Reprinted from the Hurricane Retrofit Guide by State of Florida, Division of Emergency,

Bureau of Mitigation:

- Figure 2: Impact Resistant Glass after being struck by 2 x 4 Missile;

- Figure 3: Example of Roll-Down Shutter;

- Figure 4: Example of Side-Hinged Shutter;

- Figure 5: Example of Horizontal Sliding Accordion Shutter System;

- Figure 7: Garage Door blown inward.

C. Figure 6: (http://www. hardwaresource.com) - Example of Bermuda/Bahamas Style Shutters

http://www.google.com/imgres?q=bermuda+shutters&hl=en&sa=X&tbo=d&biw=1280&bih=822&tbm=isch&tbnid=CaOOCGxK9CAewM:&imgrefurl=http://www.hardwaresource.com/hinges/SHUTTER%2Band%2BWINDOW/Shutter%2BHardware/24%2BInch%2BBermuda%2BShutter%2BStay&docid=UEpHhSQtOkYIpM&imgurl=http://www.hardwaresource.com/images/products/Bermuda_Shutters.jpg&w=353&h=529&ei=jz8iUeD7FIiC8ATylIDABQ&zoom=1&iact=hc&vpx=285&vpy=128&dur=514&hovh=275&hovw=183&tx=87&ty=136&sig=117947303926021999617&page=1&tbnh=155&tbnw=104&start=0&ndsp=30&ved=1t:429,r:2,s:0,i:117


16.0 Illustrations Attached to this Document

Attachment A - Drawings 1-6: Illustrations on Wind Borne Debris Protection - 2012 North

Carolina Residential Code

Attachment B - Drawings 1-4: Illustrations on Wind Borne Debris Protection - 2012 North

Carolina Building Code

Attachment C - Continental United States Land Falling Hurricanes 1950-1994

This Document does not constitute an evaluation of any vendor’s product nor does this document

imply that the Code Enforcement Official must approve any specific material, design, or method.


Attachment C- Continental United States Land Falling Hurricanes 1950-1994

NCDOI OSFM Evaluation · PDF fileDOI File # WP-002-10 (Rev. 2013) Wind-borne Debris...

Documents

Transcript of NCDOI OSFM Evaluation · PDF fileDOI File # WP-002-10 (Rev. 2013) Wind-borne Debris...