Walls & Ceilings logo
search
cart
facebook twitter linkedin youtube youtube Spotify Podcasts Apple Podcasts Spotify Podcasts Apple Podcasts
  • Sign In
  • Create Account
  • Sign Out
  • My Account
Walls & Ceilings logo
  • NEWS
  • TOPICS
    • Drywall
    • Stucco/EIFS
    • Ceilings
    • Steel Framing
    • Fireproofing
    • Interior Plaster
    • Building Envelope
    • Insulation
    • Technology
    • Interior
    • Exterior
    • Women In Construction
  • COLUMNS
    • Up Front
    • All Things Gypsum
    • Art & Craft of Plastering
    • Stucco Stop
    • Steel Deal
    • Industry Voices
  • PRODUCTS
    • Buzz Guide
  • EVENTS
    • Industry Events
    • Webinars
    • BUILD Expo
  • MEDIA
    • Videos
    • Podcasts
    • Photo Galleries
    • BUILD26 Videos
    • Take our Quiz!
    • Infographics
  • EXCLUSIVE
    • Newsletters
    • Top 50 Contractors
    • Contractor of the Year
    • State of the Industry
    • W&C Store
    • Market Research
    • CEUs
    • Sponsor Insights
    • Custom Content & Marketing Services
  • DIRECTORY
  • EMAGAZINE
    • eMagazine
    • Advertise
    • Archive Issues
  • SIGN UP!
Fireproofing

Decoding UL and cUL Full-Scale Fire Testing for Horizontal Membrane Assemblies

By Mitchell Schittler
certainteed horizontal membrane assemblies

IMAGE CREDIT: Who Is Danny?/Shutterstock.com

February 21, 2022

The built environment is truly only as good as the sum of its parts, and as the demands of the spaces where we live, work, learn, and play increase, the materials and products that comprise them must evolve with those demands. So, too, must the means by which we test, measure, and verify the efficacy of these products.

Across the industry, building products in residential and commercial structures are receiving increasing scrutiny for their life safety performance. On many projects, occupant wellbeing focuses on what inhabitants can see, hear, and feel—the way the design details come together to stir excitement, invoke tranquility, and otherwise appeal to the senses. 

But even more critical to occupant wellbeing is what cannot be seen, heard, or felt: the building components that may not contribute to the aesthetic value of a space but are nevertheless crucial to life safety. There is heightened awareness of everything from indoor air quality to sustainable materials among manufacturers, contractors, and specifiers alike.

The net result is that the manufacturing, testing, and certification of building products are becoming more rigorous in helping to ensure safer, more sustainable, more livable structures.

Fire Prevention Floor Over Floor

At or near the top of the list of concerns is fire safety. Today’s commercial, multi-family, and institutional buildings must comply with hundreds of International Building Code and National Building Code of Canada fire safety codes to protect occupants in the event of a fire. 

Building products designed to help prevent the spread of fire can allow occupants precious time to evacuate. Even minutes in emergency situations can mean the difference between life or death.

Vertical separators are one part of the equation in preventing or slowing the spread of fire and smoke. Horizontal separators are often overlooked as another. Fire can spread floor over floor just as easily as it can spread between spaces divided by partitions on a single floor. Specifiers must therefore also make horizontal fire and smoke separation a central part of the planning and design of multi-story building projects.

This is where horizontal shaftwall assemblies come into play. These key building components require specific consideration to meet code compliance and keep the people who occupy commercial, multi-family, and institutional buildings safe. And as more and more projects incorporate horizontal shaftwall assemblies, the demand for full-scale ASTM E119 and CAN/ULC-S101 fire-rated products is also growing.  

Horizontal membrane assemblies are non-loadbearing structures that are particularly beneficial in providing fire-resistance ratings for spaces that can’t incorporate typical floor-ceiling assemblies (which include subflooring or floor toppings) or roof-ceiling assemblies (which often include the roofing system), as specified in the UL, cUL and ULC assemblies. This means horizontal membranes offer alternatives for use in corridors, occupied space and plenum separation, exit stairways, and other areas where a standard floor-ceiling or roof-ceiling assembly is not architecturally feasible.

Code Compliance + Life Safety Assurance

While horizontal shaftwall systems are not new, limitations in testing capabilities in the marketplace has kept full-scale testing per ASTM E119 and CAN/ULC-S101 from proliferating widely in the past. That trend is beginning to change at the manufacturing level, but design and specification must follow suit.

The first step is awareness. Because full-scale tested products have not yet become an industry norm, awareness among specifiers remains low.

Currently, the industry relies largely on evaluation reports issued by third-party companies to certify building product fire code compliance. Evaluation reports are based primarily on small-scale testing, or they use vertically tested assemblies in a horizontal orientation. These methods may not provide the same fire resistance when tested in a full-scale, horizontal orientation, per ASTM E119 or CAN/ULC-S101.  

Architects and Specifiers, however, are no longer limited to evaluation reports alone. Manufacturers now have the capabilities to conduct full-scale UL, cUL and ULC testing. With stringent procedures, full-scale testing offers a more accurate picture of the way fire-rated horizontal membrane assemblies will perform in real-world applications. Full-scale testing therefore provides architects and specifiers additional assurances that the products they specify are suitable for life safety for the occupants.

Decoding the Test Methods

With more of the gypsum industry beginning to understand the benefits of full-scale testing, some manufacturers now provide multiple full-scale testing options. Several manufacturers even provide one and two-hour horizontal membrane systems that meet ASTM E119 and CAN/ULC-S101.

The following graphics illustrate the various methods used by one industry manufacturer for full scale testing of horizontal membrane systems.

UL/cUL I507: This testing protocol provides a one-hour fire resistance rating, using a minimum 6”, 33 mil steel stud, and three layers of 5/8” type X, 5/8” moisture- and mold-resistant type X, or 5/8” type C drywall.       


UL/cUL I514: This testing protocol provides a two-hour fire resistance rating, using a minimum 6”, 33 mil steel stud, four layers of 5/8” type C, with resilient channel between the third and fourth layer.


UL/cUL I515 one and two-hour testing: UL/cUL I515 utilizes 1” gypsum shaftliner plus two layers of 5/8” type X, 5/8” moisture- and mold-resistant type X, or 5/8” type C drywall for a one-hour rating. The two-hour rating utilizes 1” gypsum shaftliner plus three layers of 5/8” type C drywall, with resilient channel between the middle and face layers.

one hour test.pngUL/cULI515 one-hour test 
two hour test.pngUL/cUL I515 two-hour test

 

Additional Benefits

With many manufacturer’s products, the use of full-scale fire-rated assemblies can also meet additional objectives in today’s building standards, particularly in the area of health and sustainability.

Look for gypsum products that include Health Product Declarations (HPDs), many of which are third-party verified, for additional transparency in the material makeup. Many products also offer product-specific Type III Environmental Product Declarations, and select products even meet GREENGUARD® Gold and CDPH V1.2 requirements.

As the demand continues to grow for enhanced life safety, occupant comfort, and sustainability in the buildings people occupy, it is imperative for the industry to adopt more full-scale testing of products. Ultimately, the built environment will become safer and more livable — which benefits developers, builders, architects, and occupants alike.

KEYWORDS: building codes commercial buildings IBC (International Building Code) residential building shafts

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Certainteed mitchell schittler

Mitchell Schittler is the Technical Marketing Manager at CertainTeed Gypsum. 

Recommended Content

JOIN TODAY
To unlock your recommendations.

Already have an account? Sign In

  • Abercrombie & Fitch

    EIFS in 2026: How Specialty Finishes Are Redefining Exterior Wall Systems

    As building codes, owner expectations, and design demands...
    Stucco/EIFS
    By: Regi Mendoza
  • proper air and vapor control

    From Energy Efficiency to Moisture Management: Why Air and Vapor Control Matter

    How proper air and vapor control within building...
    Building Envelope
    By: Benjamin Meyer AIA, LEED AP
  • Linear Metal Ceiling Beam Baffles

    Top 25 Ceiling Contractors of 2026

    Suspended ceilings demand precision, code compliance and...
    Ceilings
    By: John Wyatt and Tanja Kern
You must login or register in order to post a comment.

Report Abusive Comment

Manage My Account
  • eMagazine Subscription
  • Newsletters
  • Online Registration
  • Manage My Preferences
  • Subscription Customer Service

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the Walls & Ceilings audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of Walls & Ceilings or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • medical professionals moving a patient on a stretcher through the halls of a medical building
    Sponsored byNational Gypsum Company

    What Does High Performance Mean When It Comes To Gypsum Boards?

Popular Stories

Linear Metal Ceiling Beam Baffles

Top 25 Ceiling Contractors of 2026

Wichita Biomedical Campus

Wichita Drywall Worker Dies After Scaffolding Fall

Construction workers in safety vests install drywall

Gypsum Sales Hold Amid Market Shifts in the U.S.

QXO Just Changed the Game-Here's What Contractors Are Asking

QXO Just Changed the Game-Here's What Contractors Are Asking

Events

June 24, 2026

The Bright Side & Benefits of Designing with Integrated Lighting

Credits 1 AIA LU/HSW; 0.1 ICC CEU

This course will explore the pivotal role architects and lighting design play in creating safer, more sustainable spaces. Learn how to avoid common lighting mistakes and make informed decisions that create the best visual environment for occupants. 

January 1, 2030

Webinar Sponsorship Information

For webinar sponsorship information, visit www.bnpevents.com/webinars or email webinars@bnpmedia.com.

See our full library of webinars

View All Submit An Event

Products

2026 National Painting Cost Estimator

2026 National Painting Cost Estimator

See More Products

Related Articles

  • ATI Expands Fire Testing Accreditation

    See More
  • ATI Expands Fire Testing Accreditation

    See More
  • Fire Testing and Certification

    See More

Related Products

See More Products
  • plaster and drywall

    Plaster and Drywall Assemblies Manual

  • Drywall: Professional Techniques for Great Results, 4th Edition

  • bim 3e.jpg

    BIM Handbook: A Guide to Building Information Modeling for Owners, Designers, Engineers, Contractors, and Facility Managers, 3rd Edition

See More Products
×

Connect with the industry’s leading resource for unparalleled insights and education.

Join thousands of industry professionals today. Shouldn’t you know what they know?

JOIN NOW
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
  • SIGN UP TODAY
    • Create Account
    • eMagazine
    • Newsletters
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • Instagram
    • YouTube
    • X
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2026. All Rights Reserved BNP Media, Inc. and BNP Media II, LLC.

Design, CMS, Hosting & Web Development :: ePublishing