Wednesday, December 7, 2016

Good News if You Use Open Joist Systems

Rarely do I report anything technical on this blog simply because I really don't understand what the reports are talking about but when I was a GC I used an Open Joist floor system and I know many modular builders also use them. Now they are equivalent to the fire rating of a 2x10 floor joist.

Here is the latest news about this great system:

Open Joist Announces Fire Code Breakthrough

Emlenton, PA – November 16, 2016 – Allegheny Structural Components today announced that the fire endurance of the company’s Open Joist floor trusses has been certified as equivalent to the fire endurance of 2X10’s.  Certification is confirmed in IAPMO Report ER480.

Open Joist can replace 2X10’s to satisfy the building codes’ “Fire Protection of Floors” (Exception 4) section.  When installing Open Joist in a first floor system over a basement, there is no requirement for a gypsum membrane installed on the bottom of the joists.

“The fact that Open Joist, without fire-retardant coating, can perform as well in fire as solid dimension lumber is another tribute to this remarkable product” stated Brian Ellenberger, company President and CEO.  “Now, systems builders can take advantage of wider spacing, open-web mechanicals access and a lifetime floor system warranty without suffering extra material and installation costs.”

For more detailed information, factory builders are urged to contact Dennis Sill, Director of Sales at 574-532-6102 or

Larry Kroh
Allegheny Structural Components, Inc.
3778 Oneida Valley Road
Emlenton, PA  16373

Number: 480
Originally Issued: 11/16/2016 Valid Through: 11/30/2017
Page 1 of 2

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The product described in this Uniform Evaluation Service (UES) Report has been evaluated as an alternative material, design or method of construction in order to satisfy and comply with
the intent of the provision of the code, as noted in this report, and for at least equivalence to that prescribed in the code in quality, strength, effectiveness, fire resistance, durability and safely,
as applicable, in accordance with IBC Section 104.11. This document shall only be reproduced in its entirety.

Copyright © 2016 by International Association of Plumbing and Mechanical Officials. All rights reserved. Printed in the United States. Ph: 1-877-4IESRPT • Fax: 909.472.4171
web: • 4755 East Philadelphia Street, Ontario, California 91761-2816 – USA

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Open Joist 2000® and Open Joist TriForce® Wood
CSI Section: 06 17 53 – Shop-Fabricated Wood Trusses
The Open Joist 2000® and Open Joist TriForce® wood trusses recognized in this report, have been evaluated for equivalent fire-resistant construction to dimension lumber of 2-inch by 10-inch nominal dimension in accordance with Exception 4 of Section R302.13 of the 2015 International Residential Code (Section R501.3 of the 2012 International Residential
Code) in compliance with the following code editions:

•2015 and 2012 International Residential Code®

Use of the wood trusses recognized in this report is subject to the following limitations.
2.1 The Open Joist 2000® and Open Joist TriForce® wood trusses have only been evaluated for the fire-resistance requirements noted in Section 1.0. All other requirements shall be evaluated by an approved evaluation service.

2.2. Selection of the floor trusses for structural loading and its supporting structure shall be designed by a licensed professional.

2.3 The trusses shall be properly braced in accordance with the installation instructions and the IRC.

3.1 Design. Open Joist 2000® and Open Joist TriForce® wood trusses shall be designed in accordance with manufacturer's’ design information, ANSI/AWC National Specification for Wood Construction (NDS) and evaluation reports by an approved and accredited certification agency.

3.1.1 Fire Resistance Construction. A minimum 9 3 /8-inch (238 mm) deep truss at a maximum spacing of 24 inches shall (610 mm) be required to offer equivalent fire performance to 2-inch by 10-inch nominal dimension solid sawn lumber and are recognized for installation without the prescribed minimum ½-inch-thick (12.7 mm) gypsum wallboard or 5/8-inch (15.9 mm) thick wood structural panel membrane in accordance with Exception 4 to the 2015 IRC Section
R302.13 or Section R501.3 for the 2012 IRC when installed as described in this report.
3.2 Installation. Installation of the Open Joist 2000® and Open Joist TriForce® shall be in accordance with manufacturer’s installation guide, this evaluation report and the applicable provisions of the IRC. The joists are imprinted with the words top and bottom on their respective
flanges to assure installation is as designed. Where there is a conflict between these documents, the most restrictive provisions shall govern. The manufacturer’s installation
instructions and this report shall be available at the jobsite during construction for use by installers and for quality assurance.

4.1 General: Open Joist 2000® and Open Joist TriForce® wood trusses are prefabricated open web floor joists constructed of solid-sawn wood. Web members are connected to flanges by adhesively bonded finger joints.

4.1.1 Flanges. The top and bottom flanges are constructed of solid-sawn finger-jointed Spruce-Pine-Fir (SPF) lumber with a minimum 2-inch by 3-inch nominal dimension.

4.1.2 Web Members. The vertical and diagonal web members are constructed of minimum nominal 2-inch by 2-inch SPF lumber. A 5/8-inch wood structural panel or ½-inch gypsum board attached to each side of a 5/8-inch wood structural panel or 2-inch by 8-inch solid-sawn lumber web is provided on one end which is allowed to be cut, according to manufacturer’s installation instructions, to adjust the length of the joist.

4.1.3 Adhesive. The adhesive used for manufacturing the trusses complies with ASTM D2559 and qualifies under the heat durability performance requirements of ASTM D7247.

The bottom flange of the product is imprinted with the manufacturer’s name, manufacturer’s phone number, product name, approved inspection agency, the UES Mark of conformity and evaluation report number (ER-480). Either UES Mark of Conformity may be used as shown below:
Number: 480
Originally Issued: 11/16/2016 Valid Through: 11/30/2017
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6.1 Report of Fire-resistance in accordance with ASTM E119 from a laboratory in compliance with ISO/IEC 17025.

6.2 Technical Assessment of Fire Performance.

6.3 Engineering analysis.

6.4 Manufacturer’s quality documentation, descriptive literature and installation instructions.

Allegheny Structural Components, Inc.
3778 Oneida Valley Road
Emlenton, Pennsylvania 16373
Phone: (724) 867-1100
Barrette Structural, Inc.
555 Rang St-Malo
Trois-Rivieres, Quebec G8V 0A8
Phone: (800) 263-7265

This evaluation report describes the results of research carried out by IAPMO Uniform Evaluation Service on Open Joist 2000® and Open Joist TriForce® wood trusses to assess their conformance to the codes shown in Section 1.0 of this report and documents the product’s certification.

Brian Gerber, P.E., S.E.
Vice President, Technical Operations
Uniform Evaluation Service
Richard Beck, PE, CBO, MCP
Vice President, Uniform Evaluation Service
GP Russ Chaney
CEO, The IAPMO Group

For additional information about this evaluation report please visit or email at


Builder Bob said...

Coach, more information about the products we use is always helpful. Waiting for our sales reps to tell us this stuff whould have us waiting forever.

You are a great source of information about everything modular. Consider adding more of this type of stuff.

William aka "Little Bill" said...

Also, the nice thing about Open Joist 2000 is that there is now an 11-1/4" joist available. For years, it was 9-1/4 to match a 2x10 but than 11-7/8". This was useless because it would not match up with a 2x12. But after years of complaining from builders and manufacturers, Open Joist 2000 is now producing a 11-1/4" joist as a standard size. This alone is great news.