December 1, 2014 TO: PARTIES INTERESTED IN STRUCTURAL WOOD-BASED PRODUCTS SUBJECT: Proposed Revision to the ICC-ES Acceptance Criteria for Structural Wood-Based Products, Subject AC47-1214-R2-2 (JF/PC) Dear Colleague: We are seeking your comments on a proposed revision to the subject acceptance criteria, as presented in the enclosed draft. The revision was posted on the ICC-ES web site for public comment in October 2014 and received favorable comments from the public. This revision reflects changes in the ASTM D5456 standard which will likely be referenced in future editions of the International Building Code (IBC) and International Residential Code (IRC). The affected report holders have agreed to re-analyze their existing data and to complete revisions to their reports, as appropriate, by April 15, 2015, if the proposed revision to the criteria is approved. At this time, there are no proposed revisions to Appendix A of this criteria. Therefore, it is not included. While the Evaluation Committee will be voting on the revised criteria during the 30- day comment period, we will seriously consider all comments from the public and will pull the criteria back for reconsideration if public comments raise major issues. In that case, we will further revise the draft, post it for a new round of public comments and seek a new Committee vote; or put the revised criteria on the agenda for a future Evaluation Committee hearing. If the revision is of interest, please review and send us your comments at the earliest opportunity. At the end of the 30-day comment period, we will post on our web site the correspondence we have received and, in memo form, the responses of our technical staff. To submit your comments, please use the form on the web site and attach any letters or other materials. If you would like an explanation of the alternate criteria process, under which we are soliciting comments, this too is available on the ICC-ES web site.
AC47-1214-R2-2 2 Please do not try to communicate directly with any Evaluation Committee member about a criteria under consideration, as committee members cannot accept such communications. Thank you for your interest and your contributions. If you have any questions, please contact me at (800) 423-6587, extension 5593, or Ping Cheng, at extension 3535. You may also reach us by e-mail at es@icc-es.org. Yours very truly, JRF/raf Enclosure cc: Evaluation Committee Jeff R. Filler, Ph.D., P.E. Staff Engineer
www.icc-es.org (800) 423-6587 (562) 699-0543 A Subsidiary of the International Code Council PROPOSED REVISIONS TO THE ACCEPTANCE CRITERIA FOR STRUCTURAL WOOD-BASED PRODUCTS AC47 Proposed December 2014 Previously approved February 2013, February 2011, October 2010, October 2009, June 2009, October 2006, October 2004, February 2004, June 2003, September 1997, September 1995, May 1995 (Previously editorially revised February 2014, February 2012) PREFACE Evaluation reports issued by ICC Evaluation Service, LLC (ICC-ES), are based upon performance features of the International family of codes. (Some reports may also reference older code families such as the BOCA National Codes, the Standard Codes, and the Uniform Codes.) Section 104.11 of the International Building Code reads as follows: The provisions of this code are not intended to prevent the installation of any materials or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety. ICC-ES may consider alternate criteria for report approval, provided the report applicant submits data demonstrating that the alternate criteria are at least equivalent to the criteria set forth in this document, and otherwise demonstrate compliance with the performance features of the codes. ICC-ES retains the right to refuse to issue or renew any evaluation report, if the applicable product, material, or method of construction is such that either unusual care with its installation or use must be exercised for satisfactory performance, or if malfunctioning is apt to cause injury or unreasonable damage. NOTE: The Preface for ICC-ES acceptance criteria was revised in July 2011 to reflect changes in policy. Acceptance criteria are developed for use solely by ICC-ES for purposes of issuing ICC-ES evaluation reports.
PROPOSED REVISIONS TO THE ACCEPTANCE CRITERIA FOR STRUCTURAL WOOD-BASED PRODUCTS (AC47) 1.0 INTRODUCTION 1.1 Purpose: The purpose of this acceptance criteria is to establish minimum requirements for recognition of structural wood based products in evaluation reports under Sections 104.11 and 2303.1.9 of the 2012, 2009 and 2006 International Building Code (IBC), Sections 106.4 and 2303.4 of the BOCA National Building Code/1999 (BNBC), Section 103.7 of the 1999 Standard Building Code (SBC) and Section 104.2.6 of the 1997 Uniform Building Code (UBC). Chapters 5, 6 and 8 of the 2012, 2009 and 2006 International Residential Code (IRC) are applicable to the structural wood-based product covered in this criteria. The criteria utilizes ASTM D5456 as the basis for recognition of the structural wood-based products. 1.2 Scope: The structural wood-based products are used as an alternative to sawn lumber for wall, floor and roof structural members. The structural wood-based products covered by this criteria are limited to solid rectangular members or hollow members of varying shapes fabricated from solid rectangular laminations. Structural wood-based products used as rim board, load bearing studs, and in shear wall and fire-resistance-rated applications require additional evaluation as noted in Section 2.1.7. For purposes of this criteria, laminated veneer bamboo (LVB) is considered to be a wood-based product. 1.3 Codes and Reference Standards: 1.3.1 2012, 2009 and 2006 International Building Code (IBC), International Code Council. 1.3.2 2012, 2009 and 2006 International Residential Code (IRC), International Code Council. 1.3.3 BOCA National Building Code/1999 (BNBC). 1.3.4 1999 Standard Building Code (SBC). 1.3.5 1997 Uniform Building Code (UBC). 1.3.6 ASTM D2559-09, Standard Specification for Adhesives for Structural Laminated Wood Products for Use under Exterior (Wet Use) Exposure Conditions, ASTM International. 1.3.7 ASTM D3737-08, Standard Practice for Establishing Allowable Properties for Structural Glued Laminated Timber (Glulam), ASTM International. 1.3.8 ASTM D5456-09 [-09a, where specified], Standard Specification for Evaluation of Structural Composite Lumber Products, ASTM International. 1.3.9 ASTM D5764-97a (2007), Standard Test Method for Evaluating Dowel-Bearing Strength of Wood and Wood-based Products, ASTM International. 1.3.10 ASTM D6815-09, Standard Specification for Evaluation of Duration of Load and Creep Effects of Wood and Wood-Based Products, ASTM International. 1.3.11 ASTM D7247-07ae1 Standard Test Method for Evaluating the Shear Strength of Adhesive Bonds in Laminated Wood Products of Elevated Temperatures, ASTM International. 1.3.12 AF&PA NDS-2012, National Design Specification for Wood Construction and Supplement, American Forest and Paper Association. 1.3.13 Department of Commerce Voluntary Product Standard PS 2-10, Performance Standard for Wood-based Structural-use Panels. 1.3.14 ICC-ES Acceptance Criteria for Test Reports (AC85). 1.3.15 ICC-ES Acceptance Criteria for Rim Board Products (AC124). 1.3.16 ICC-ES Acceptance Criteria for Wood-based Studs (AC202). 1.3.17 ICC-ES Acceptance Criteria for Quality Documentation (AC10). 1.4 Definition: Structural wood-based products are limited to structural composite lumber defined in ASTM D5456 and the products described in Sections 3.5, 3.6, 3.7, and 3.8 of this criteria. 2.0 BASIC INFORMATION 2.1 Testing Laboratories, Reports of Tests and Product Sampling: 2.1.1 Testing laboratories shall comply with Section 2.0 of the ICC-ES Acceptance Criteria for Test Reports (AC85) and Section 4.2 of the ICC-ES Rules of Procedure for Evaluation Reports. 2.1.2 Test reports shall comply with AC85. All reports shall be issued by an accredited testing laboratory. Tests conducted at a manufacturer s facility shall be under the control of and witnessed by an accredited testing laboratory. The manufacturer s test facility is considered a subcontractor of the accredited laboratory. The accredited laboratory shall ensure that the relevant requirements of Section 4.2 of the ICC-ES Rules of Procedure for Evaluation Reports are fulfilled. 2.1.3 Specimen Sampling Methods: Specimen sampling methods shall comply with Section 3.1 of AC85 and Section 6.2 of ASTM D5456. 2.1.4 Specimen Description: Measured dimensions shall be recorded for each specimen in accordance with the degree of accuracy specified in the ASTM standards. Additionally, statements are needed indicating whether specimens were produced in accordance with the minimum requirements of the approved quality control manual. 2.1.5 Test Results: In addition to the requirements noted in ASTM D5456, the failure mode for each specimen shall be described. 2.1.6 Test Conclusions: Test results shall be limited to species, thickness of veneers or laminations and grade of veneers or laminations used in specimens tested, unless additional data is submitted which justifies extrapolation of test results to a range of material composition. 2.1.7 Additional Data Required: Use of structural wood-based products for rim board, load bearing studs, shear wall and fire-resistive applications requires additional considerations beyond those noted in ASTM 2
ACCEPTANCE CRITERIA FOR STRUCTURAL WOOD-BASED PRODUCTS (AC47) D5456 and this criteria. See AC124 and AC202 for additional details involving rim board, load bearing studs and shear wall applications. 3.0 TEST PERFORMANCE AND ANALYSIS 3.1 General: Testing and analysis of data shall be in accordance with ASTM D5456, unless noted otherwise in this criteria. 3.2 Connections: Connection testing shall be in accordance with ASTM D5456, and must be conducted on each wood species and each grade unless recognition of fasteners is based on the most conservative wood species and the lowest grade. Details of the test shall be discussed with the ICC-ES staff before the testing begins. 3.2.1 Withdrawal Capacity of Nails: Withdrawal capacity testing and analysis must be in accordance with appropriate sections of Annex 2 to ASTM D5456. 3.2.2 Lateral Load Capacity of Fasteners (Dowel Bearing Strength): For lateral load capacity of fasteners, dowel bearing strength tests shall be conducted in accordance with this section and ASTM D5764. The analysis of data shall be in accordance with Annex A2 of ASTM D5456. 3.3 Adhesive Heat Durability: In addition to the requirements noted in Section 4.2 of ASTM D5456, adhesives used in laminated veneer lumber (LVL) and parallel strand lumber (PSL), as defined in ASTM D5456, as well as adhesives used in the products described in Sections 3.5, 3.6, and 3.8 of this criteria, shall be qualified for heat durability performance through testing in accordance with Section 4.2.1 of ASTM D5456-09a. 3.4 Structural Composite Lumber (SCL): Structural composite lumber shall comply with ASTM D5456 and the applicable sections in this criteria. Exception: The flatwise reference design value for compression perpendicular-to-grain, F c, of structural composite lumber (SCL) may alternatively be taken as the lesser of the following: a. Average proportional limit stress. b. Average of the stress at 0.04-in. deformation maximum compressive stresses recorded, up to a maximum strain of 0.05 for each specimen. Under this exception, compression perpendicularto-grain testing shall be in accordance with the applicable provisions of ASTM D5456 Section 6, except that the minimum sample size determined in accordance with Section 6.2.4 need not exceed that based on the mean value at the 0.04-inch deformation level. When using this alternative method to derive the flatwise reference design value for compression perpendicular-to-grain, the average strain associated with each reference design value shall be reported within the evaluation report. The flatwise reference design values for F c determined using this exception shall be the characteristic values from the test results of the flatwise compression perpendicular to grain adjusted by a factor of 1.0. For flatwise reference design values for F c determined using this exception, the The evaluation report shall also include a statement indicating that these values are not permitted to be adjusted by the NDS-specified bearing area factor, C b. 3.5 Alternative Strand Lumber: 3.5.1 Steam-pressed Scrim Lumber (SPSL): Steam-pressed scrim lumber evaluated under this criteria is defined as a composite of wood scrims (matts of wood strands) obtained through crushing small-diameter logs and glued together in a steam-injection press so that the wood fibers are primarily oriented along the length of the member. The least dimension of the strands in the scrim shall not exceed 3 / 4 inch (19 mm). The average length of the strand shall be greater than 20 times their least dimension. In addition to testing per ASTM D5456 and the applicable sections of this criteria, the following shall apply to SPSL: 3.5.1.1 The material shall be tested in accordance with and meet the thickness swell requirements noted in Section 4.2 of AC124. 3.5.1.2 The material shall meet the bond durability requirements noted in Sections 5.3.3.1(b), 5.3.4.1, and 5.3.4.3 of PS-2. 3.5.1.3 Lateral edge nail durability testing shall be conducted in accordance with Section 4.3 of AC124 or Section 6.8.2 of ASTM D5456. 3.5.1.4 The adhesive shall comply with Section 4.2 of ASTM D5456, and shall meet the heat durability requirements of Section 3.3 of this criteria. 3.5.2 Triangular Strand Lumber (TSL): Triangular strand lumber is similar to SCL defined in ASTM D5456, except that TSL is a composite of wood strands of substantially equilateral triangular cross section with the wood fibers primarily oriented along the length of the member. The least dimension of the strands shall not be less than 0.25 inch (6.4 mm) and the average length shall be a minimum of 75 times the least dimension. 3.5.2.1 Testing per ASTM D5456 and the applicable sections of this criteria is required. 3.6 Advanced Engineered Lumber (AEL): Advanced engineered lumber evaluated under this criteria is defined as a composite of variable thickness using sawn wood laminations where the wide or narrow faces are laminated to produce solid or hollow members of varying shapes. Lamination thickness ranges from 0.10 inch (2.54 mm) to 2.0 inches (50.8 mm). The minimum beam depth for solid members shall be 6 inches (152 mm). The minimum depth beam for hollow members shall be 3 inches (76 mm). Structural glued laminated timber (glulam), manufactured in accordance with ANSI A190.1, American National Standard for Wood Products, Structural Glued Laminated Timber, and ASTM D3737, is not considered as an AEL. 3.6.1 Compliance with the requirements noted in Sections 2.1, 3.1, 3.2, 3.3, and 4.0 in this criteria, except as noted in Section 3.6.2, is required. Creep and DOL need to be addressed, either by tests (ASTM D5456 or other test method acceptable to ICC-ES), or by analysis (current glulam practice). 3.6.2 Longitudinal shear strength shall be evaluated in accordance with ASTM D3737, Annex A7, Test Setup and Data Analysis Procedure for Determining Horizontal Shear Stress by Full Scale Beam Tests. 3.6.3 An analysis and/or test data shall be submitted addressing possible issues such as web buckling and fastener penetration, resulting from joist hangers 3
ACCEPTANCE CRITERIA FOR STRUCTURAL WOOD-BASED PRODUCTS (AC47) connecting to the side, or supported from the top of hollow members. 3.7 Proprietary Solid Sawn Wood Products Used for Deck Boards and Guardrail Systems: 3.7.1 Proprietary Hardwood Used for Deck Boards and Guardrail Systems: Solid sawn hardwood used for deck boards and guardrail systems may be evaluated under this criteria as a structural wood-based product. 3.7.1.1 Testing and analysis of data for bending strength, bending stiffness, longitudinal shear strength, moisture content and specific gravity shall be in accordance with ASTM D5456. 3.7.1.2 Connections shall be designed in accordance with the NDS, using the average specific gravity. Adjustments for wet-service conditions shall be used if exposed to the weather. 3.7.2 Modified Wood Used for Deck Boards and Guardrail Systems: For the purposes of this criteria, thermally modified wood is defined as solid sawn hardwood or softwood that has been subjected to an advanced dry kiln process that substantially reduces hemicellulose content, and acetylated wood is defined as solid sawn hardwood or softwood that has been subjected to a chemical modification process in which acetyl groups are covalently bonded to accessible hydroxyl sites within the cell walls of the wood. Both modification processes result in wood that is less hygroscopic. Thermally modified wood and acetylated wood used for deck boards and guardrail systems may be evaluated under this criteria as a structural wood-based product, provided they are either: (1) manufactured from hardwood or softwood lumber that has not been previously graded in accordance with IBC Section 2303.1.1, or (2) manufactured from previously graded hardwood or softwood lumber that has subsequently been ripped, sawn or otherwise machined to a different cross-sectional dimension. In addition to Sections 1.0, 2.0, 3.1, 3.2 and 4.0 of this criteria, Sections 3.7.2.1 through 3.7.2.5 shall apply. Details of the sampling and testing program shall be discussed with ICC-ES staff prior to the tests being conducted. The proponent shall provide a grade rule description for the product being tested, specifying limitations on all relevant growth characteristics affecting the mechanical properties of the wood. Limitations shall include, but are not limited to, size, relative frequency, proximity, and location on the board, of strength reducing characteristics. Sampling shall be conducted at the manufacturing facility where only specimens that contain the maximum strength reducing characteristics per the grade rule are collected from throughout the production run. Photographs shall be provided for all of the sampled test specimens after they have been tested. The grade rule description may be modified at a later date (in the course of a revision to the evaluation report) to match the requalification test sample, provided that evaluation report recognition is limited to product meeting the new grade rule description. The sampling shall consider all relevant growth characteristics affecting the mechanical properties of the wood. During flexure testing, the maximum strength reducing growth characteristic shall be positioned within the high-stress region of each test specimen. 3.7.2.1 Testing and analysis of data for bending strength, bending stiffness, longitudinal shear strength, 4 compression perpendicular to grain, moisture content, and specific gravity shall be in accordance with ASTM D5456. Bending tests shall be performed on the members both before and after the thermal modification or acetylation process. Flexural strength, stiffness, and work to maximum load (WML) shall be recorded. An adjustment factor shall be derived based on the ratio of WML for the modified wood versus that of the non-modified wood, but shall not exceed 1.0. This adjustment factor shall be applied to the bending test results when deriving span ratings for the product. Moisture content and specific gravity shall also be measured both before and after the wood is thermally modified or acetylated. Additionally, a minimum of 30 full sized deck boards shall be fully submerged in water at room temperature for at least 14 days, and tested in bending at the time of their removal. Wet service factors shall be derived based on the ratio of the average bending strengths of soaked versus dry boards, but shall not exceed 1.0. The wet service factors shall be applied to the bending test results when deriving span ratings for the product. Design values shall not be published in the evaluation report. The performance ratings (e.g., span ratings) shall be published in the evaluation report in lieu of design values. 3.7.2.2 Equivalent specific gravity for connection design shall be derived in accordance with Annex A2 of ASTM D5456; however, the equivalent specific gravity assigned to the thermally modified or acetylated wood shall not exceed the actual specific gravity of the wood before it is thermally modified or acetylated. Design values for connections shall be calculated in accordance with the NDS, using the equivalent specific gravity. Adjustments for wet-service conditions shall be used if exposed to the weather. 3.7.2.3 Tests shall be conducted to verify that the specified spacing of nails of various diameters is adequate to prevent splitting. Details of the testing shall be discussed with ICC-ES staff prior to the tests being conducted. 3.7.2.4 A test plan shall be developed for testing the decay resistance of the thermally modified or acetylated wood used for deck boards and guardrail systems, based on applicable sections of the ICC-ES Acceptance Criteria for Proprietary Wood Preservative Systems Common Requirements for Treatment Process, Test Methods and Performance (AC326). At a minimum, the deck boards and guardrail systems shall be tested for aboveground, weather-exposed use (AWPA Use Category 3B), with the exception that termite resistance tests are not required unless recognition for termite resistance is sought in accordance with Section 3.7.2.5 of this criteria. 3.7.2.5 If recognition is sought for use in applications requiring protection against termites, the requirements of IBC Section 2304.11.6 and IRC Section R318 shall be met. Details of the testing program shall be discussed with ICC-ES staff prior to the tests being conducted. If recognition is not sought for use in such applications, the evaluation report shall include installation requirements and/or limitations on use, such that protection against termites is not required in accordance with IBC Section 2304.11.6 and IRC Section R318. 3.7.2.6 For acetylated wood that is intended to be used with fasteners and/or connection hardware consisting of metals other than stainless steel, corrosion
ACCEPTANCE CRITERIA FOR STRUCTURAL WOOD-BASED PRODUCTS (AC47) resistance testing shall be performed in accordance with the ICC-ES Acceptance Criteria for Evaluation of Corrosion Effects of Wood Treatment Chemicals (AC257). This testing is not required if recognition is sought for use with stainless steel fasteners and connection hardware only. In such cases, the evaluation report shall include a statement indicating that fasteners and connection hardware used in contact with the acetylated wood must be stainless steel. 3.8 Laminated Veneer Bamboo (LVB): The product is made from 1 / 4-inch-thick (6.35 mm), 3 / 4-inch-wide (19.1 mm) and 96-inches-long (2438 mm) bamboo strips bonded together to form a mat, which is laminated to other mats of the LVB product. In addition to testing per ASTM D5456 and the applicable sections of this criteria, the following shall apply to LVB: 3.8.1 Dimensional stability testing shall be in accordance with Section 5.3.2.1(a) of PS 2. 3.8.2 Lateral edge nail durability testing shall be conducted in accordance with Section 6.8.2 of ASTM D5456. 3.8.3 The product shall be tested in accordance with and meet the thickness swell requirements noted in Section 4.2 of AC124. 3.8.4 In addition to complying with ASTM D2559 and Section 3.3 of this criteria, the adhesives shall be tested in accordance with the alternative method noted in Section 4.2 of ASTM D5456. 3.8.5 Tests shall be conducted to verify that the specified spacing of nails of various diameters is adequate to prevent splitting. Details of the testing shall be discussed with ICC-ES staff prior to the tests being conducted. 4.0 QUALITY CONTROL 4.1 Quality control shall comply with Sections 8, 9 and 10 of ASTM D5456. The products shall be manufactured under a quality control program with inspections by a properly accredited inspection agency that has a contractual relationship with ICC-ES. 4.2 Quality documentation complying with the ICC-ES Acceptance Criteria for Quality Documentation (AC10) and Appendix A of this criteria shall be submitted for each facility manufacturing or labeling products that are recognized in the ICC-ES evaluation report. 4.3 A qualifying inspection shall be conducted at each manufacturing facility when required by the ICC-ES Acceptance Criteria for Inspections and Inspection Agencies (AC304). 4.4 Quality control documentation for proprietary hardwood, thermally modified wood, acetylated wood and laminated veneer bamboo shall include the specific species and the location where the wood or bamboo is harvested, along with other unique characteristics and the grading requirements, including ongoing quality assurance test requirements to ensure a consistent product. In the cases of proprietary hardwood, thermally modified wood and acetylated wood, the grading requirements shall consider all relevant growth characteristics affecting the mechanical properties of the wood, and shall specify limitations on their size, relative frequency and proximity, location on the board, etc. 5
ACCEPTANCE CRITERIA FOR STRUCTURAL WOOD-BASED PRODUCTS (AC47) Appendix A not included. 6