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Firestop Systems: An Important Line of Defense for Fire Safety

This article will focus on root causes of improper firestop system specification, installation, inspection and maintenance and offer best practices to help minimize these issues.

Photo of Firestopping, Joint Protection and Perimeter Fire Containment

October 10, 2022

Authors:  Mark St. Onge, UL Solutions Senior Field Engineer, Field Engineering/Customer Experience and Jonathan Roberts, UL Solutions Senior Regulatory Engineer, Codes and Regulatory Services, Customer Experience, Distinguished Member of Technical Staff

Within the building industry there are growing concerns regarding the improper system specification, installation, inspection and maintenance of passive fire protection systems such as firestop. The failure to follow necessary firestop system specifications and installation instructions can lead to project delays and project cost overruns. This article will focus on the root causes of these job site concerns and suggest best practices to help minimize these issues.

Passive and active fire protection

A balanced and systematic approach to building fire safety includes both active and passive fire protection systems. Active fire protection systems include fire sprinkler and fire alarm systems while passive fire protection systems include fire resistance rated assemblies (walls and floor ceiling assemblies), fire doors, dampers and firestop systems. Fire containment (also called fire compartmentalization) provided by passive systems helps keep a fire from spreading beyond the designated fire area and provides protected exits for the safe egress of occupants. Passive fire protection systems are also intended to provide sufficient time for first responder arrival and activation of any installed active protection system for a time period required by the various model building, fire and life-safety codes.

Therefore, passive systems must be designed, installed, inspected and maintained in accordance with the requirements of the adopted code. Taking this balanced approach helps ensure the model code required level of fire and life safety for building occupants is achieved and maintained.

Model codes and certification standards

Code compliance should be the responsibility of all stakeholders involved with building design, construction, operation and maintenance. Compliance does not rest solely with a plans examiner or building official. To achieve code compliant buildings, it is essential that designers, contractors/installers, building owners and managers are also knowledgeable about the fire and life safety requirements found in the model building and fire codes.

This article is intended to enhance reader understanding of the model code requirements related to the specification, approval, installation, inspection and maintenance of these firestop systems found in:

  • National Fire Protection Association (NFPA) 101 Life Safety Code, 2021 edition (Chapter 8 and Section of the annex)
  • NFPA 1, Fire Code, 2021 edition (Chapters 1, 4 and 12)
  • International Building Code (IBC) and International Fire Code (IFC), 2021 edition (Chapter 7 and 17), collectively I-Codes.

The NFPA codes and the I-Codes include requirements related to where certified (listed) firestop systems are required to help maintain the integrity of the passive fire protection for a fire area. Additional requirements within these documents also specify methods for the proper installation, testing and maintenance (ITM) of those systems.

One provision found in the IFC requires the owner (or designee) to maintain a list of the building’s installed passive fire protection systems, including protections such as: firestop systems, spray applied fire-resistant material (SFRM), intumescent fire-resistant material (IFRM), opening protectives and fire and smoke dampers. Proper identification and code-compliant installation helps to ensure these systems will be adequately maintained for the life of a building. Code required periodic building inspections can be more efficient when building owners provide inspectors with inspection, testing and maintenance documentation from qualified contractors or approved third-party inspectors when model codes define this as an owners responsibility. When owners conduct and document passive fire protection system inspections, the code authority can more easily verify code compliance through review of the owner provided documentation.

Code requirements for special inspections and audits

The addition of model code requirements for special inspection of passive fire protection systems and components has changed the passive fire protection industry over the past several model code cycles. These new requirements have led to an increased demand for properly trained and qualified inspectors with an increased level of specialized knowledge and experience for proper firestopping installation and ITM.

Having qualified personnel performing inspections has helped to identify a variety of noncompliance issues of installed firestop systems that would not have been otherwise identified and corrected. Improper past practices at the construction site included a contractor simply using a red fire caulk for every penetration, without any certification that this material has been tested to the required standard for the code mandated hourly fire rating.

Another improper practice identified when inspections are performed by qualified individuals is known in the construction industry as scab patching. This is where a small piece of gypsum board is simply screwed in place over a hole in an assembly instead of using a proper method specific intended for maintaining the integrity of the passive fire-resistance assembly. Here again, there is no third-party certification that shows this construction site practice compliances with the model code requirement for installation of listed firestop systems in these applications.

Non-tested construction site methods such as these have led to an increase in model code requirements for specialized and periodic ITM by qualified personnel for elements of passive fire protection such as firestop systems, fire doors and fire and smoke dampers. When a breakdown in proper ITM occurs, the level of fire and life safety of a building may be reduced significantly over time.

Standards for fire stop system inspection practices

Standards have been developed to provide guidance for conducting on-site inspections of these passive fire protection systems, including:

ASTM E-2174, Standard Practice for On-Site Inspection of Installed Firestops, and ASTM E-2393, Standard Practice for On-Site Inspection of Installed Fire Resistive Joint Systems and Perimeter Fire Barriers, contains valuable guidance for code authorities special inspector’s and the inspector’s employment agency.

Additional requirements for an inspection agency to be qualified as well as the individual inspector are outlined in ASTM E-699, Standard Specification for Agencies Involved in Testing, Quality Assurance, and Evaluating of Manufactured Building Components and ASTM E-329, Standard Specification for Agencies Engaged in Construction Inspection, Testing, or Special Inspection.

Until the model building, fire and life-safety codes add specific requirements for firestop contractors to demonstrate competency, the code authority responsible for approving passive fire protection system installation and ongoing ITM need to establish appropriate requirements for their jurisdiction. It is therefore left to the code authority to establish the method or policy they believe will provide them with confidence in verifying the code compliance of these systems.

As part of their approval process, code authorities can also require an accreditation audit of any contracted third-party firestop inspection agency. These accreditations utilize audits to scrutinize the reports being issued to determine compliance with standard requirements, such as: inspectors meet the requisite knowledge and experience qualifications, specific records are being retained and that the other accreditation requirements are successfully met. It is important to note that the value obtained from an accreditation is different from other designations that can be obtained in the firestop industry. Some designation programs are not subject to independent third-party review, so code authorities are encouraged to review the designation requirements and process before acceptance.

Education and training

The development of new model code requirements, focused on proper firestop system specification, system certification (listing), competent installation and inspection for verification of code compliance, has increased the need for training, education and certification programs for designers, contractors and code authorities. Simply relying on the ways things have always been done does not equate to installation of firestop systems meeting the most current building, fire and life safety codes.

Education and training programs based on the evolution of the model code requirements for passive fire protection is imperative. Code authorities at every level are encouraged to invest in these education, training and qualification programs and should insist that designers and contractors/installers make the same investment. Job site delays due to failed inspections can be significantly reduced or eliminated through education and training that ensures competent and qualified personnel are involved at each step of the design and construction process.

Plan review and field inspections

The importance of a thorough plan review is another critical step to help ensure code compliance for occupant fire and life safety. This plan review should include construction documents submitted by the design professional with a building permit application specifying the necessary details about certified assemblies, systems and components to enable a plans examiner to easily verify code compliance. Following a comprehensive plan review and issuance of the building permit, and an approved set of plans provides the necessary details required for installers/contractors and code officials to verify code compliance at a construction site.

For efficient construction site inspection, all construction documents should be current and accurate. In order to make that possible, UL Solutions offers an online database that includes UL Certified (listed) firestop systems, specification or verification. All the most up to date information can be easily accessed using the online certification database, UL Product iQ®, available at Product iQ is complimentary to use but does require a simple one-time registration.

A suggested best practice for initial plan review is to require that the UL Solutions guide information be included in the submittal documentation (construction documents) for all relevant category control numbers (CCNs). The Guide Information for each CCN provides essential information related to each product or system and provides important technical information pertaining to UL Certified products. While the individual certifications provide specific information, the UL Solutions guide information applies to all products or systems within a specific CCN. This information can be easily viewed, downloaded or printed from Product iQ®.

At the building site, another best practice includes having each firestop inspected by a qualified third-party inspector who can provide a firestop special inspection label when the firestopping passes inspection. This label provides evidence to code authorities that the UL Certified firestop system has been properly installed and makes it easier to verify compliance of the installation during final inspection for issuance of the certificate of occupancy. Many contractors and firestop manufacturers already provide these labels as part of their installation or as a service to support their products.

Qualifications for contractors and manufacturers

Typically, unqualified contractors are prohibited from installing essential life safety systems such as fire sprinkler systems, fire alarm systems or building electrical systems because contractors/installers must be trained and competent in their trade. In most jurisdictions, there are specified ways in which competency may be demonstrated including through licensure, individual credentialing or company accreditation programs.

UL Solutions has developed programs for qualifying both the firestop installers and for system manufacturers writing Engineering Judgements (EJs). These programs were developed in collaboration with UL Solutions customers, the Firestop Contractors International Association (FCIA) and the International Firestop Council (IFC). Installers can demonstrate knowledge and experience via the UL Qualified Firestop Contractor Program (UL CCN RFTI) by passing the UL Solutions firestop industry knowledge exam and utilizing a quality management system-based audit to verify the required elements of firestop installation.

Manufacturers are sometimes requested to write Engineering Judgements (EJs) for firestop systems when no certified systems are available. Because there currently are no standards describing the essential requirements for preparing EJs, some EJs are being written without oversight or competency in firestop systems testing standards. Best practices solution dictates that an EJ should have a basis in science and testing which serves to explain how the proposed construction or system meets the intent of the applicable model code requirements. This is best achieved by someone with knowledge in the test standards, products being used and their associated fire test data.

In response to industry concerns, UL Solutions is developing the soon to be released Technical Evaluation Developer Program. Manufacturers participating in this program must develop a quality manual, pass qualification exams specific to each type of firestop system category for which they write EJs, be audited by UL Solutions annually and satisfactorily demonstrate compliance on established program requirements. The manufacturers in the Technical Evaluation Developer program are required to log each EJ into a UL Solutions system where a percentage of each manufacturer’s EJs will be randomly selected for annual audit. This program is intended to drive EJs to qualified individuals that can support their decisions through records of their process and consistent documentation of the audit results. When appropriate, this program can also lead to the creation of additional certified firestop systems based on test reports in accordance with the appropriate fire test standards.


The model building, fire and life safety codes have added many new requirements relating to firestop systems over the past code revision cycles. Knowledge and competency on these new requirements are essential for all engaged in building safety, including design professionals, plan reviewers, contractors, code authorities, third-party inspectors and building owners and managers.

Proactive approaches for ensuring code complaint construction and maintenance of buildings are essential for occupant safety. Best practices such as preconstruction meetings in which a design team, contractors, installers, building officials and other stakeholders identify areas of concern and collaborate on potential solutions is an important step. Utilizing qualified contractors to install firestop systems following the joints and penetrations made in fire resistance-rated construction by electricians, plumbers or other construction trades is also paramount to a positive final inspection without unnecessary delays and costs.

Requiring firestop systems to be properly specified and documented, installed by competent contractors and properly inspected to determine code compliance is essential to ensuring that the passive fire protection of a building meets or exceeds the required minimum level of safety for building occupants.  UL Solutions offers several programs that help design professionals and code authorities with all aspects of delivering code compliant firestop systems through proper specification and installation by competent and qualified firestop contractors.

Using installers without specific firestop installation training or experience may lead to an increased failure rate of firestopped penetrations during the code compliance inspection, thereby causing delays and cost overruns or worse yet, fail during a fire event.

Although these programs and practices can be challenging to implement, many municipalities that have experienced the benefits of doing so. While it may take some upfront time and effort to initiate these best practices, once started they are easy to maintain with relatively low cost throughout the life of a building.  These comprehensive programs and best practices serve to provide confidence that the important line of defense created by a balance of passive and active fire protection meets code requirements for installation, inspection and maintenance through the useful life of a building.

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