April 2, 2018 PARTIES INTERESTED IN CROSS LAMINATED TIMBER PANELS USED AS COMPONENTS IN FLOOR AND ROOF DECKS

Size: px
Start display at page:

Download "April 2, 2018 PARTIES INTERESTED IN CROSS LAMINATED TIMBER PANELS USED AS COMPONENTS IN FLOOR AND ROOF DECKS"

Transcription

1 April 2, 2018 TO: PARTIES INTERESTED IN CROSS LAMINATED TIMBER PANELS USED AS COMPONENTS IN FLOOR AND ROOF DECKS SUBJECT: Proposed Revisions to the ICC-ES Acceptance Criteria for Cross-laminated Timber Panels for Use as Components in Floor and Roof Decks, Subject AC R1 (PC/JF/WG) Dear Colleague: We are seeking your comments on the proposed revisions to the subject acceptance criteria, as presented in the enclosed draft, which is being posted for 30 days of public comment on the ICC-ES web site. The proposed revisions were requested by one of the ICC-ES evaluation report holders and staff. The proposed revisions are summarized below: 1. Modify Section 1.1 by relocating the referenced code sections to a new Table 1. The reason for this modification is to improve readability. 2. Modify Sections 1.1 and 1.2 to include the 2018 IBC and corresponding editions of referenced standards. 3. Add a new Section for conversion of reference in-plane shear design values. 4. Editorially changes throughout the criteria. While the Evaluation Committee will be voting on the revised criteria during the 30-day comment period, we will consider all comments from the public and will pull the criteria back for reconsideration if public comments raise major issues. In that case, we would seek a new committee vote; further revise the draft and post it for a new round of public comments; or put the revised criteria on the agenda for a future Evaluation Committee hearing. Should the committee approve the proposed revisions to the criteria, ICC-ES staff will not recommend a mandatory compliance date, as the proposed revisions do not include substantive technical revisions. If they are of interest, please review the proposed revisions 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.

2 AC R1 2 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. 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) , extension 3535, or Jeff Filler, PhD, P.E., Senior Staff Engineer, at the extension You may also reach us by at es@icc-es.org. Yours very truly, PC:JF:WG/raf Encl. cc: Evaluation Committee Ping Cheng, P.E. Senior Staff Engineer

3 (800) (562) A Subsidiary of the International Code Council PROPOSED REVISIONS TO THE ACCEPTANCE CRITERIA FOR CROSS-LAMINATED TIMBER PANELS FOR USE AS COMPONENTS IN FLOOR AND ROOF DECKS AC455 Proposed April 2018 Previously approved April 2017, February 2015 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 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. Acceptance criteria are developed for use solely by ICC-ES for purposes of issuing ICC-ES evaluation reports. Copyright 2018 ICC Evaluation Service, LLC. All rights reserved.

4 PROPOSED REVISIONS TO THE ACCEPTANCE CRITERIA FOR CROSS- LAMINATED TIMBER PANELS FOR USE AS COMPONENTS IN FLOOR AND ROOF DECKS (AC455) 1.0 INTRODUCTION 1.1 Purpose: The purpose of this acceptance criteria is to establish requirements for evaluation of cross-laminated timber (CLT) panels to be recognized for use as components in floor and roof decks in an ICC Evaluation Service, LLC (ICC-ES), evaluation report under the 2018, 2015, 2012 and 2009 International Building Code (IBC). Bases of recognition are IBC Section and other applicable IBC sections as noted in Table 1 of this criteria IBC Sections 602, (Type I and II Construction), (Type III Construction), (Type IV Construction), (Cross-laminated timber floors), (Cross-laminated timber roofs), 2303 (Minimum Standards and Quality), and (Structural glued cross-laminated timber) and 2012 and 2009 IBC Sections (Type I and II Construction), (Type III Construction), (Type IV Construction), (Floors), (Roofs), (Combustible material in Type I and II Construction), and 2303 (Minimum Standards and Quality for Wood). The reason for the development of this criteria is that the codes and the code-referenced design standards do not include sufficient provisions for the evaluation of CLT panels for use as components in roof decks in Type I and II Construction (IBC) and in roof and floor decks in Type III (interior floor decks only), IV or V construction (IBC). 1.2 Scope: This criteria is applicable to the evaluation of CLT panels used as components in floor and roof decks and qualified in accordance with ANSI/APA PRG Codes and Referenced Standards: , 2015, 2012, 2009 International Building Code (IBC), International Code Council ASTM D b (-13 for the 2015 IBC, -09 for the 2012 IBC and -05a for the 2009 IBC), Standard Specification for Evaluation of Structural Composite Lumber Products, ASTM International ASTM E (-12a for the 2015 IBC, -08a for the 2012 IBC and -07 for the 2009 IBC), Standard Test Methods for Fire Tests of Building Construction and Materials, ASTM International ANSI/APA PRG (-12 for the 2015 IBC), Standard for Performance-Rated Cross-Laminated Timber, American National Standard Institute/APA The Engineered Wood Association ANSI/AWC NDS-2018 (-2015 with 2015 NDS Supplement for the 2015 IBC), National Design Specification (NDS) for Wood Construction with 2018 NDS 2015 Supplement, American Wood Council. 1.4 Definitions: Cross-laminated Timber (CLT): A prefabricated engineered wood product consisting of not less than three layers of solid-sawn lumber where the adjacent layers are cross-oriented and bonded with structural adhesive to form a solid wood element. Page 2 of CLT Lamination: An individual piece of solidsawn lumber or structural composite lumber (SCL) having the cross-sectional dimensions in compliance with ANSI/APA PRG 320 and meeting the requirements of ASTM D CLT Layer: All laminations on one side of a face bondline for panel face or all laminations between two adjacent bondlines for others CLT Floor and Roof Deck: Floor or roof deck assembly consisting of CLT panels as components, supporting in-plane shear loads and out-of plane transverse loads CLT Panel: A single CLT billet Parallel Layer: All laminations oriented parallel to the major strength direction in CLT panels Perpendicular Layer: All laminations oriented parallel to the minor strength direction in CLT panels CLT Layup: an arrangement of layers in a CLT panel Face Bondline: Refer to Section 3.2 of Edge Bondline: Refer to Section 3.2 of Major Strength Direction: Parallel to the general orientation of wood grain in the laminations of the top and bottom face layers of the CLT panel; also referred to as the parallel direction Minor Strength Direction: Perpendicular to the major strength direction; also referred to as the perpendicular direction. 2.0 BASIC INFORMATION 2.1 General: The following information shall be submitted: Product Description: Cross-laminated Timber (CLT) Panels: Complete information concerning CLT panel grades, layups, dimensions and dimensional tolerances, squareness, straightness, and the manufacturing process CLT Laminations: Complete information concerning sawn lumber grades, species and species groups, sizes, minimum specific gravity, moisture content and, end joints in sawn lumber. For SCL laminations, SCL grades, wood species, sizes, minimum equivalent specific gravity, and moisture content Bondline: Complete information concerning the face bondline and edge bondline Adhesives: Adhesive specifications are to include the type, class, adhesive spread rate, brand and manufacturer name, and ICC-ES evaluation report number (if applicable) Installation Instructions: Installation instructions (including a description of the method of field cutting, application and finishing of the CLT panels, if they

5 PROPOSED REVISIONS TO THE ACCEPTANCE CRITERIA FOR CROSS-LAMINATED TIMBER PANELS FOR USE AS COMPONENTS IN FLOOR AND ROOF DECKS (AC455) are not done at the factory), limitations, procedures and handling instructions Packaging and Identification: A description of the method of packaging and field identification of the cross-laminated timber panels. Identification provisions shall include the manufacturing layup combination, grade, sizes, and name of the cross-laminated timber panel fabricator, evaluation report number. The identification shall be visible after the CLT panel is installed. 2.2 Testing Laboratories: 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. 2.3 Test Reports: Test reports shall comply with the ICC-ES Acceptance Criteria for Test Report (AC85). 2.4 Product Sampling: CLT panels shall be sampled in accordance with Sections 3.1, 3.3, and 3.4 of AC85. CLT panels sampled shall be representative of the standard manufactured CLT panel products to be evaluated. 3.0 TEST AND PERFORMANCE REQUIREMENTS 3.1 CLT Panel General Requirements: CLT panels shall be manufactured and qualified in accordance with 3.2 CLT Panel in Floor and Roof Deck Evaluations: The CLT panels for use as components in floor and roof decks shall be tested and analyzed for both out-of plane transverse loading and in-plane shear loading in accordance with Section 4.0. A description of CLT panels used in the construction of test specimens shall include the CLT panel grades, layups, thickness, width, length, installation orientation of the CLT panels. 4.0 TEST METHODS AND ANALYSIS REQUIREMENTS 4.1 General: Where otherwise specified in this criteria, number of identical CLT panel specimens consisting of each CLT panel grade/layup/thickness combination for which recognition is sought shall be in accordance with An adjustment factor of 2.1 is applied to the characteristic test in-plane shear values determined in accordance with Section of this criteria when determining reference allowable in-plane design shear stress For in-plane shear load testing, the testing shall be conducted in accordance with Section 4.3 of this criteria. The CLT panel specimens shall be CLT panels consisting of CLT panel grade/layup/thickness combination for which recognition is sought. The loading apparatus, application of loading, duration of load application and deformation measurement shall be in accordance with Annex A3 of ASTM D Out-of-plane Transverse Load Tests: Out-of-plane transverse load tests, including bending and shear load tests, sampling, sample conditioning, test methods, and analysis of test data shall be in accordance with provisions as specified in Section 8.5 of ANSI/APA PRG 320. Structural performance evaluation for each Page 3 of 4 layup of CLT panels sought for recognition shall comply with Section 7.2 of 4.3 In-plane Shear Load Tests: Test Method: The short-beam edgewise bending test method specified in Annex A3 of ASTM D5456 shall be used to conduct the in-plane static load tests. The test procedure shall be in accordance with Annex A3 Section A3.3 of ASTM D Sample Size: The minimum sample size shall be in accordance with Annex A3 Section A3.2.1 of ASTM D5456, which is Test Specimen Details: The depth, or the width, of I-shaped cross-section and the length of CLT panel test specimens shall be in accordance with Annex A3 Sections A3.2.3 and A3.2.5, respectively. The I-shaped cross-section shall be fabricated in accordance with Annex A3 Section A3.2.4 by adding flanges of the same materials to the tension and compression zones of the rectangular section. The web thickness of I-shaped cross-section shall be the thickness, or layup, of CLT panel sought for recognition. The test specimens shall include edge joints between CLT laminations in the CLT layer parallel to the span of test specimens located near the mid-height, or the neutral axis, of the depth of the test specimens Configurations of Test Specimens: Depending on the orientation of the major strength direction in respect to the loading direction, the major strength direction of the CLT panels may be parallel to or perpendicular to the loading direction. The in-plane static load tests shall be conducted on each orientation of the major strength direction of the CLT panel for which recognition is sought Conditioning of Test Specimen: The test specimens shall be conditioned in accordance with Annex A3 Section A3.2.2 of ASTM D5456 prior to testing Analysis: Analysis of test results for each layup, sealed by a registered design professional, shall be provided to determine the following: The apparent in-plane shear strength shall be determined in accordance with Annex A3 Section A3.4.1 of ASTM D5456 for each test specimen The characteristic value shall be determined in accordance with Annex A3 Section A3.4.2 of ASTM D The allowable reference in-plane design shear stress shall be determined by dividing the characteristics value from Section by an adjustment factor noted in Section of the criteria The reference in-plane design shear capacity of the total thickness of a CLT panel shall be determined by multiplying the reference in-plane design shear stress, determined in Section , by the gross thickness of the CLT panel Test Report: The test report shall comply with the ICC-ES AC85 and Annex A3 Section A3.4 of ASTM D Other Considerations: Fire Resistance: CLT panels used as components in floor and roof decks and requested to be

6 PROPOSED REVISIONS TO THE ACCEPTANCE CRITERIA FOR CROSS-LAMINATED TIMBER PANELS FOR USE AS COMPONENTS IN FLOOR AND ROOF DECKS (AC455) recognized for fire resistance shall be tested in accordance with ASTM E119 and shall be rated for fire resistance in accordance with the results and conditions of such tests. As an alternative to testing, the fire resistance for the exposed CLT members shall be permitted to be calculated in accordance with Chapter 16 of the NDS Adjustment Factors for Reference Design Properties Values: Load Duration Factor, C D: Load duration factor shall be as specified in Section of the NDS for CLT panels used as components in floor and roof decks. Load duration factor does not apply to the modulus of elasticity, compression perpendicular to grain, and rolling shear of CLT panels Time-dependent Deformation (Creep) Factor, K er: The creep factor, K er, shall be 2.0 as specified in Section of NDS for CLT panels used as components in floor and roof decks under dry service conditions when the moisture content in lumber in service is less than 16%, as in most covered structures Temperature Factor, C t: The temperature factor shall be as specified in Section of the NDS, when CLT panels used as components in floor and roof decks experience sustained exposure to elevated temperature up to 150 o F Wet Service Factor, C M: The wet service factor, C M, shall be 1.0 for CLT panels used in dry service conditions where the moisture content in lumber in service is less than 16 percent, as in most covered structures. 5.0 QUALITY CONTROL 5.1 The CLT panels used as components in floor and roof decks shall be manufactured under an approved quality control program with inspections by ICC-ES or an inspection agency that has a contractual relationship with ICC-ES. 5.2 Quality documentation complying with the ICC-ES Acceptance Criteria for Quality Documentation (AC10) shall be submitted for each facility manufacturing or labeling CLT panel products that are recognized in the ICC-ES evaluation report. 5.3 A qualifying inspection shall be conducted at each facility manufacturing or labeling CLT panel products when required by the ICC-ES Acceptance Criteria for Inspections and Inspection Agencies (AC304). 6.0 EVALUATION REPORT RECOGNITION 6.1 Basic information required by Section 2.1 of this criteria, including component description, installation procedures, and packaging and identification information 6.2 Reference design values with the associated adjustment factors for the out-of-plane loading for each CLT panel layup, based on analysis of data as described in Sections 4.2 of this criteria. 6.3 Reference design values with the associated adjustment factors for the in-plane loading loads for each CLT panel layup, based on analysis of data described in Section 4.3 of this criteria. 6.4 The evaluation report is to include a statement that CLT panels used as components in roof and floor decks have not been evaluated for diaphragm design and the diaphragm design is out of the scope of the evaluation report. 6.5 To be considered as part of a floor or roof diaphragm, CLT panels used to resist in-plane shear forces in floor and roof diaphragms shall be accompanied by complete detailing and diaphragm design that are acceptable to the code official. 6.6 The evaluation report is to include a statement that the CLT roof decks shall be covered with approved roof coverings secured to the building or structure in accordance with applicable provisions of IBC Chapter The evaluation report is to include a statement that the CLT panels used as components in floor and roof decks are limited to the use in dry service conditions, i.e., the moisture content in the wood is less than 16%. 6.8 The evaluation report is to include a statement that the special inspection shall be conducted in accordance with the applicable requirements of Sections 1704 and 1705 of the IBC. 6.9 The evaluation report is to include a statement that the CLT panels used as components in floor and roof decks under the IRC when engineered design is submitted in accordance with Section R TABLE1 APPLICABLE IBC SECTIONS AS BASES FOR CROSS-LAMINATED TIMBER SECTION IBC EDITION x x x x x x x x x x x x x x x x x x x x x x x x 2303 x x x x x x x x Page 4 of 4