AC14-0213-R1

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PRIEST & ASSOCIATES CONSULTING, LLC

P January 18, 2013 Micheal O’Reardon, P.E Regional Manager ICC Evaluation Service, Inc.

Subject: Proposed Revisions to the Acceptance Criteria for Prefabricated Wood I-joists, Subject AC140213-R1 (JS/DC) Priest and Associates (PAC) have reviewed the proposed changes to AC14 and offer our comments for consideration by the committee and staff. We are writing to convey our concerns over the proposed addition of new Sections A4.4.5 through A4.4.6 in terms of practicality and reasonableness. As background, PAC has many years of experience with the accelerated weathering protocols employing ASTM D2898 (and variations thereof, including ICC ES AC107) for the conditioning of fire-retardanttreated and preservative-treated wood roofing and structural products, as well as wood-plastic composite lumber. We are also experienced in the use of the radiant exposure methodology employing ASTM E1623 (the Intermediate Scale Calorimeter, commonly referred to as the “ICAL” apparatus) for the evaluation of the thermal resistance characteristics of a myriad of products, including protected and unprotected wood-based substrates, and played a primary role in authoring Section A4.4.5.2 of the proposed revision to AC14. The proposed environmental exposure conditions provided for in Sections A4.4.5 are as follows: A4.4.5.1 Exposure Conditions: Exposure conditions shall be as follows: a. Evaluate moisture cycle effect: A minimum of three specimens shall be conditioned with a 72hour water spray on the protected face in accordance with Section 7.3.2 of ASTM E661, followed by a redry period to the original weight ± 2 percent prior to testing. b. Evaluate three-cycle freeze-thaw effect, including 24-hour water soak: A minimum of three specimens shall be conditioned in accordance with Section 4.7 of ASTM D7032, followed by a redry period to the original weight ± 2 percent prior to testing. c. Evaluate UV effect: A minimum of three specimens shall be conditioned by subjecting specimens to the UV exposure on the protected face in accordance with Section 4.6 of ASTM 1 D7032 prior to testing . 1

This entails a 2000 hour exposure.

It seems excessive and an over-reach to impose accelerated weathering conditions including 2000 hours of UV exposure and freeze-thaw cycling involving full water immersion followed by freezing at -21°F per ASTM D7032 on intumescent-coated OSB web stock or alternatively, complete I-joists. ASTM D7032 is entitled “Standard Specification for Establishing Performance Ratings for Wood-Plastic Composite Deck Boards and Guardrail Systems (Guards or Handrails)”, and its scope covers procedures to establish a performance rating (dealing with potential degrades in flexural strength or stiffness) for wood-plastic composite (WPC) lumber over their expected lifetime in exterior applications. We do not see the applicability of these two procedures, intended to screen out “bad actors” with WPC’s as environmental conditions appropriate for the intended use or handling of intumescent-coated I-joists.

4607 Verdi Road Pleasanton, TX 78064 www.priestassociates.com

Solutions for the Building Materials Industry

1-877-505-7743 Office 360-957-0311 Mobile [email protected]

Priest & Associates Consulting

Solutions for the Building Materials Industry

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Engineered wood I-joist product warranty requirements dictate that these products are intended for dryuse applications only and are not meant for prolonged exposure to moisture, as prolonged moisture exposure makes engineered wood products unsuitable for use. APA has a publication entitled “Proper Storage and Handling of I-Joists and LVL (EWS E705), which provides for wrapping, covering and storage of I-joists off of the ground for protection against exposure to the elements. In the absence of data, but on the strength of these requirements and warranties it is assumed that unprotected I-joists would be incapable of withstanding the proposed AC14 weathering requirements without a significant loss of strength and utility. Certainly, full immersion in water followed by freezing is contraindicated in any case. The proposed AC14 environmental exposure conditions are more rigorous than the ASTM D2898 (or AC107) conditions imposed on exterior grade FRTW materials, which again are expected to be exposed to weather conditions relevant to the lifetime of their intended end-use. It should be noted that interior grade FRTW carries care and use provisions requiring protection from the elements until installed, many times as structural sheathing on buildings exposed to the elements and prior to the installation of the weather barrier. Some exposure to weather prior to covering is tolerated. Practically speaking, it is recognized that some degree of weather exposure of manufactured fire-resistant protected I-joists (with factory-applied coatings), as with unprotected I-joists, is inevitable prior to installation. The use of simulated weather exposure conditions representative of expected use is indicated to assure that the viability of the fire protective coating is maintained prior to installation. The challenge remains to discern the anticipated conditions and length of exposure time. In place of the proposed protocols described in Section A4.4.5, consideration should be given to the use of the accelerated weathering conditioning prescribed in AC 326, Appendix J7.2, foreshortened and modified to reflect an appropriate environmental exposure time. For this regimen, the coated surface of the test specimens would be subjected to the water spray and UV/elevated temperature exposure, as well as freeze-thaw. At the end of this cycling, the specimens would be subjected to the ICAL radiant heating condition, and burn through time would be assessed. This would eliminate the possibility of failing an ICAL exposure after one of the exposure conditions specified in the proposed AC14 procedure, and reasonably addresses anticipated exposure conditions prior to the building being dried-in. In addition and for the aforementioned reasons, PAC disagrees with the “full immersion” requirement in Section A4.4.6. We appreciate this opportunity to provide our comments regarding this issue.

Sincerely,

Howard Stacy Senior Scientist/Partner HWS/hws

P

AC14-0213-R1

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AC14-0213-R1

Sent: From: To: Cc: Subject:

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Tue 1/15/2013 4:31 PM Taecker, John K. [email protected] es Walke, Richard N. [email protected] Proposed Revisions to the Acceptance Criteria for Prefabricated Wood I-joists, AC14

Comment on Proposed Revisions to the Acceptance Criteria for Prefabricated Wood Ijoists, Subject AC14-0213-R1 (JS/DC) The standards ASTM standards A653, D1037, D5664, D7032, and E1623 are referenced in the proposed changes to Sections A4.4.4 through A4.4.6, but are not included in the list of referenced standards under Section A1.3. Thanks for the opportunity to comment,

John K. Taecker Senior Regulatory Engineer ----------------------------------------UL LLC 455 E. Trimble Road San Jose, CA 95131 USA T: 408.754.6658 F: 408.689.6658 W: ul.com

AC14-0213-R1

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Codes, Standards, and Product Engineering January 18, 2013

Mr. Jason Smart ICC Evaluation Service, Inc. Birmingham Regional Office 900 Montclair Road, Suite A Birmingham, Alabama 35213 RE:

Proposed Revisions to the Acceptance Criteria for Prefabricated Wood I-joists, Subject AC14-0213-R1 (JS/DC)

Dear Mr. Smart: Thank you for the opportunity to comment on the proposed changes to the Acceptance Criteria for Prefabricated Wood I-joists, AC14. In general, we support the proposed revisions in the staff memo dated December 28, 2012. Please consider the following comments and edits below. Suggested Revision: A4.3 Fire-resistance-rated Construction (Optional): Except for recognition of wood I-joists used in assemblies 21-1.1 and 23-1.1 through 28-1.1 of 2012 IBC Table 721.1 (3), wood I-joists used in fireresistance-rated assemblies require testing in accordance with ASTM E119 or UL 263. Where paints, coatings, or treatments are factory applied to I-joists to provide some or all of the required fire resistance to the assembly, an evaluation in accordance with the requirements and conditions of Sections A4.4.2.3 and A4.4.4 through A4.4.6 shall be performed on I-joists that are painted, coated, or treated. Reason: The proposed AC14 durability requirements (Sections A4.4.4 through 4.4.6) apply to factory applied paints, coatings, or treatments used where recognition is sought for the establishment of equivalent fire performance to materials described in Exception 4, Section 501.3 of the 2012 IRC. As currently written, factory applied paints, coatings, or treatments used in E119 fire-rated assemblies are not subjected to the proposed requirements. Weyerhaeuser believes that if factory applied fire resistive material is used to aid in an I-joist's fire performance, both R501.3, Exception 4 or E119 firerated assembly, the material should be evaluated according to Sections A4.4.4 through A4.4.6. Thank you for the opportunity to comment on the proposed revisions to AC14. I look forward to answering any questions or addressing any comments you may have. Sincerely,

David M Nelson, P.E Product Acceptance Engineer

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