July 19, 2017
By Bill McHugh, CSC, CSI, MBA
Fire resistance is one of the oldest protection strategies in buildings. Continuously joined fire-resistance-rated walls and floors form ‘effective compartmentation’ for an area of any size. The objective is to limit fire spread to the area of origin. In addition to the sprinkler, alarm, and egress systems, proper design, installation, inspection, and maintenance (DIIM) of fire resistance, as well as highly effective compartmentation, is critical to protecting people
Materials that are specified in MasterFormat Section 07 84 00−Firestopping, when installed to the listing and manufacturer’s installation instructions, maintain the continuity of this fire-resistance-rated compartmentation construction. Continuous protection is introduced through application to abutments, continuous gaps, breaches at the tops and bottoms of walls, curtain wall and horizontal assemblies, and the holes made for the passage of cables and pipes. One area that is not always reviewed is the gaps, joints, and openings at adjacent assemblies.The continuity of fire resistance between adjacent building elements is specified in the National Building Code of Canada (NBC) in Sentence 18.104.22.168(4):
The continuity of a fire separation shall be maintained where it abuts another fire separation, a floor, a ceiling, a roof, or an exterior wall assembly.
In other words, the gaps at the top and bottom of gypsum fire-resistance-rated walls are required to maintain continuity by NBC. This is important, as this breach, void, gap, abutment, and holes are frequently overlooked on construction projects. The voids or holes made for sevice penetrations are equally important, and required by NBC.
Fire resistance starts with a fire-resistance-rated-assembly. Such ratings are determined through tests in conformance with Underwriters Laboratories of Canada (CAN/ULC) S101, Standard Methods of Fire Endurance Tests of Building Construction and Materials.
In addition to testing for fire performance, there are also calculated methods for fire resistance used with concrete assemblies. These employ the equivalent thickness needed to resist fire for a period of time.
NBC is a performance code, different from other codes in North America. The performance nature of NBC introduces the need for smoke-resistant properties of fire separations. Appendix A-22.214.171.124. (1)(b) states what the intent of the code is for compartmentation:
Although a fire separation is not always required to have a fire-resistance rating, the fire separation should act as a barrier to the spread of smoke and fire until some response is initiated. If the fire-resistance rating of a fire separation is waived on the basis of the presence of an automatic sprinkler system, it is intended that the fire separation will be constructed so that it will remain in place and act as a barrier against the spread of smoke for a period of time until the sprinklers have actuated and controlled the fire.
This passage sets up the need for firestop systems providing both fire- and smoke-resistant properties to the assembly. NBC Article 3.1.9 (“Building Services in Fire Separations and Fire-rated Assemblies”) specifies CAN/ULC-S115, Standard Method of Fire Tests of Firestop Systems, for treating breaches, gaps, voids, or openings made to accommodate movement of assemblies, separation of noncompatible materials, and insertion of service penetrating items. In this standard, there is an optional test for air leakage (L), which simulates smoke movement to result in an L-rating for the firestop system.
The air leakage rating adds smoke-resistant properties to assemblies that need them. The requirement that a fire separation resist the passage of smoke for a set period invokes the need for an L-rated firestop system.
The position of the Firestop Contractors International Association (FCIA) is that even when fire separations do not have a fire-resistance rating, a tested and listed firestop system should be used to get the air leakage rating for smoke-resistant properties. Why? Most commercial, industrial, and institutional occupancies use wall and floor assemblies approximating a fire-resistance-rated assembly, even when not rated. If the assembly approximates a tested assembly, then the L-ratings provide the closest thing to a complete tested and listed assembly offering quantified protection. The L-ratings are the ‘suitability for use’ statement of a firestop product in a specific application (i.e. for smoke). Since smoke travel is a crucial item to protect against, it makes little sense to specify anything less than an L-rated firestop system in assemblies that are considered non-fire-resistance-rated.
For firestopping, NBC states the abutment, gap, void, breach, opening, annular space size, penetrating item, covering, or similar is to be sealed based on CAN/ULC-S115.
NBC Article 126.96.36.199 (Firestopping of Service Penetrations) states:
Except as required by Sentences (2) and (3), and permitted in Sentences (4) and (5), penetrations of a fire separation or a membrane forming part of an assembly required to have a fire-resistance rating shall be:
a) sealed by a firestop system that, when subjected to the fire test method in CAN/ULC-S115, “Fire Tests of Firestop Systems,” has an F rating not less than the fire-protection rating required for closures in the fire separation in conformance with Table 188.8.131.52., or (50pa, plastics)
In NBC, there is one exception to the requirement for firestop systems tested to CAN/ULC-115. It is a very minor exception and requires ‘casting in place’ the service penetrating items when concrete is poured. It is:
b) cast in place (see Appendix A).
This exception allows concrete, equal thickness to the wall or floor, for a limited number of penetrating items and opening size. However, some penetrating items may not be compatible with cement-based products, so one must verify compatibility with cement-based products used where firestopping contacts other parts of the assembly, such as copper piping.
In short, any service penetrating items and abutments, continuous breaches, gaps, voids, or openings made for independent movement or compatibility through one or both sides of fire-resistance-rated construction should be treated with firestopping tested and listed to CAN/ULC-S115, unless they fall under the exception (b).
Without firestop system listings from a laboratory directory such as ULC’s and manufacturers’ installation instructions, it is difficult to know the fire resistance rating’s duration and whether there is protection. Some manufacturers provide engineering judgments (sometimes in conjunction with the testing laboratory or fire protection engineer) when no tested and listed system from any firestop manufacturer exists to address a field condition.
|RESISTING EXTERNAL FIRE WITH ROOFS|
|Roofs and the type of fire resistance they require have been questions in people’s minds for years. The meaning is all in the definitions. Underwriters Laboratories of Canada’s (ULC’s) test method, CAN/ULC-S101, Standard Methods of Fire Endurance Tests of Building Construction and Materials, reports results of tests of the time in minutes or hours an assembly of materials resists flame passage, supports a load, and limits temperature rise on the non-fire side of the assembly. The assembly includes the roof deck and any sprayed or intumescent fire-resistive materials (SFRM or IFRM) applied, any firestopping of service penetrating items through holes in the roof (if required), and the roofcovering (including air barrier, insulation, and roofing membrane material).CAN/ULC-S107, Methods of Fire Tests of Roofcoverings, measures the ability of a roofcovering to resist fire from a source outside the building. This test assesses the material based on four criteria. First, intermittent flames might occur as they travel across a roofcovering. Second, spreading flames occur when flaming or combustible material is on fire (evaluating the ease at which flames travel). Burning brands occur on roofs when burning debris falls on it from other structures, trees, or similar. Flying brands occur when a flaming roofcovering breaks into pieces and is carried to another part of the roof while on fire.
After completion of the fire test, a rating such as Class A, B, or C is assigned. Class A roofcoverings:
Class B is the same as Class A, except it offers moderate fire exposure and protection to the roof deck from above. Class C covers light fire exposures and provides a measurable degree of protection to the roof deck.
Burning brand sizes vary based on rating class. All classes are conditioned in an oven at 41 to 49 C (106 to 120 F) for at least 24 hours.
Class A uses a grid of 305-mm (12-in.) square and 57-mm (2-in.) thick Douglas fir lumber free of knots and pitch pockets, with nominal 25x25x305-mm (1x1x12-in.) strips of wood dressed on all four sides to 19×19 mm (3/4x3/4 in.), placed in three layers of twelve strips each. These strips are spaced 6.35 mm (¼ in.) apart, and placed at right angles to those in adjoining layers on one face in a diagonal pattern.
The Class B burning brand is smaller at 152 mm (6 in.) square, while the Class C is a piece of dry, nonresinous white pine lumber free of knots and pine lumber, 38x38x20 mm (1 ½x1 ½x8/10 in.) thick with saw kerfs applied as specified.
To get the Class A rating, a large burning brand is used in the fire test. Class B and C are subjected to smaller burning brands. Slope limitations are stated in the listing, along with deck construction supporting the roofing system and any required or optional barrier boards, ply sheets, and surfacing. This ‘topside’ roof test is not a fire resistance rating test and does not establish an hourly rating.
Another test standard provides fire-classified assemblies evaluated by either large-scale fire testing or using procedures described in CAN/ULC-S126, Standard Method of Test for Fire Spread Under Roof Deck Assemblies. This test covers flame spread under the roof deck.
To illustrate, let it be assumed a roof assembly is one- or two-hour fire-resistance-rated. It has a listing from the UL/ULC Online Certifications Directory, fire resistance section, or other accredited testing laboratory acceptable to the authority having jurisdiction (AHJ).
Can a roof system with only a CAN/ULC-S107 rating be used when the roof assembly is to be fire-resistance-rated to CAN/ULC-S101? The answer depends on the hourly fire-resistance-rated assembly listing.
Some fire-resistance-rated assemblies are proprietary and require certain roof assembly materials specified by the manufacturer that paid for the testing. The manufacturer of each material in the assembly can certainly be specified in the tested and listed system. It may also be stated as a generic product category, such as polyisocyanurate (polyiso) or mineral fibre. The maximum or minimum thicknesses of insulation is sometimes specified, and the decking gauge and thickness may be as well.
Where the listing is manufacturer-specific, each material would be listed, from the SFRM or IFRM to the roof deck, air barrier, roof insulation, and roofcovering material (including surfacing).
This testing should include any vegetated roof overburdens, as well as new photovoltaic (PV) panels used on the roof. If they are used on the rooftop, they should be tested and listed to the same requirements as the roofcovering membrane.
As mentioned, other fire-resistance-rated systems require the fire resistance from the underside to be tested and listed and instead allow a generic roofcovering or insulation. The listing might state single-ply, built-up (BUR), or modified bitumen (mod-bit) roofing, polyiso insulation, or ballasted or smooth roof surfacing.
Any Class A, B, or C system selection should meet ULC test standard requirements referring to the topside fire exposure. It may also require flame spread and smoke development ratings.
It is possible to spend much more time discussing test standards for fire resistance for many building elements, from walls and wallpaper to equipment used in and on buildings. Learning the difference between hourly fire-resistance-rated and topside fire spread protection for buildings is an important first step.
Illuminating DIIM: Design, installation, inspection, and maintenance
By focusing on the proper DIIM of firestopping, continuity of fire resistance can be maintained.
The first component of the DIIM philosophy is the design. In this stage, systems are designed by manufacturers of firestop products and tested to CAN/ULC-S115 at labs such as UL/ULC, FM Approvals, Intertek, or other authority-having-jurisdiction (AHJ)-recognized laboratory.
The tested and listed systems provide ‘suitability for use statements’ for the fire- and smoke-resistant products. They become systems once installed by those who understand the specific application’s installation instructions.
The other part of design is the specification writer, who understands the complexity of firestopping and does due diligence to specify to meet the building’s physical needs.
Who is to install firestopping? This industry is different from other industries, such as roofing and waterproofing. There is no contract binding the contractor and manufacturer through a long-term warranty program, as would be found in the roofing industry.
For this reason, and to increase the quality of life-safety firestop installations, FCIA collaborated with FM Approvals to build FM 4991, Standard for the Approval of Firestop Contractors, and with UL/ULC to develop the UL/ULC Qualified Firestop Contractor Program. Both programs provide general contractors, building owners, and managers a way to differentiate between companies that believe firestopping is a technical discipline with detailed systems and those that simply pump red sealant on or in assemblies and refer to it as firestopping.
Firestop contractor companies approved under the FM 4991 standard or qualified under the UL/ULC Qualified Firestop Contractor Program have procedures in place to understand system listings and manufacturers’ installation instructions.
There are several steps to becoming approved under the FM 4991 or qualified under the UL/ULC Qualified Firestop Contractor Program. First, the company must employ someone who has passed an exam based on the FCIA Firestop Manual of Practice (MOP) and the FM and UL/ULC Programs.
Second, a management system is written by the firestop contractor company, and procedures are implemented. Then, an onsite audit of the company management system (by FM or ULC) takes place. The person who passes the UL/ULC or FM firestop exam is then appointed as a designated responsible individual (DRI) at the company, depending on which program is chosen.
The FM 4991 and UL/ULC contractor programs are quite different from the manufacturer programs in the marketplace. Rather than short education sessions by a single manufacturer to get certificates or cards, these are true third-party programs, with FM 4991 designated as an FM standard. The programs are specified nationally in contractor requirements. They cost the contractor about $8000 for the initial audit, and $4375 for each annual audit. For a contractor, that is a small investment when compared to labour and materials.
In some countries, special inspection is mandated by the building code. In Canada, specifications might reference inspection standards such as ASTM E2174, Standard Practice for Onsite Inspection of Installed Firestops, and ASTM E2393, Standard Practice for Onsite Inspection of Installed Fire Resistive Joint Systems and Perimeter Fire Barriers.
Referenced in MasterFormat Section 07 84 00, Part 3−Execution, ASTM E2174 and ASTM E2393 inspection provides procedures for inspection. This is an independent check to ensure the contractor’s management system installing firestopping is working properly.
Companies providing this inspection should also be vetted. International Accreditation Services (IAS), a subsidiary of the International Code Council (ICC), has an Accreditation Criteria (AC) 291, Accreditation Criteria for Special Inspection Agencies. IAS provides accreditation to inspection agency companies that use a management system it has audited and employ a person who has passed the FM or UL/ULC exam.
It is FCIA’s position that individual inspectors or contract employees also need to have qualifications, in addition to the company accreditation. The FM or UL/ULC exam provides individuals proof they have knowledge of firestopping. Then, the building owner should ensure the inspection company hired has appropriate experience, competence, independence, and equipment, as well as employing individuals who have inspected the same type and complexity of firestopping as that represented on the specific project.
Firestopping is included in the fire-resistance-rated system maintenance sections of codes throughout the world, including the National Fire Code of Canada (NFC) and the International Fire Code (IFC) in the United States.
In Division B–Part 2, “Building and Occupant Fire Safety,” NFC also has a short, but specific, reference to maintenance:
184.108.40.206–Damage to Fire Separations: Where fire separations are damaged so as to affect their integrity, they shall
be repaired so that the integrity of the fire separation
From this language, it seems the integrity of the fire separation is meant to be continuous (i.e. maintained at all times). Section 220.127.116.11 of NBC states, “where fire separations are damaged…they shall be repaired.”
In the 2015 IFC, there is a requirement for annual visual inspection of fire-resistance-rated or smoke-resistant assemblies by the building owner under Section 703.1.
How many building owners and managers have a line item in their operating budgets to repair these abutments, voids, gaps, openings, breaches, or holes in fire separations? How many have a sprinkler maintenance or alarm maintenance budget? In surveys of audiences during barrier/fire separation educational symposiums, it has been found the fire-separation budget is a new concept to the building owner and manager and growing.
Firestopping as a system and 07 84 00
Throughout North America, firestopping is a systems-oriented installation. The product alone does not get a rating. The rating comes from the products installed to the tested and listed system and manufacturer’s installation instructions. This means products must be installed to the tested and listed ‘system’ from a nationally recognized testing laboratory before the entire assembly becomes a fire and life safety-tested and listed firestop system.
It takes a firestop contractor who specializes in this complex work to understand all the details involved in accomplishing this. He or she also knows how to supervise the workforce so people do not get ‘creative’ in the field and veer away from the tested and listed systems.
Inspection of firestopping is important as well. However, if the firestop contractor does not get the systems installed correctly, inspection time and costs will skyrocket, as this is generally an hourly fee rather than fixed price. Inspection needs to be specified to be bought by the building owner and manager, not the general contractor, to maintain independence.
Firestop contractors who specialize in complex tested and listed systems, manufacturers’ installation instructions, and detail are needed to maintain continuity of fire resistance.
Where is the future of fire resistance going? Qualifications are continually being developed for companies installing, inspecting, and maintaining fire-resistance-rated construction and the features that protect fire separations.
FCIA has been proactive about developing programs to help specifiers, building owners, and managers provide standards from which to specify quality in firestop installations and hire firestop contractors and inspection agencies in a quantifiable way. By joining the quality management process manufacturers embraced long ago, firestop contractors and special inspection agencies are leading the quality movement in the subcontracting world.
Specifiers have been adding the DIIM requirements for firestopping to construction documents through the standards listed above (e.g. FM 4991, UL/ULC standards, and IAS AC-291), and some projects are using this method of construction. The trend needs to continue to grow so buildings are safe for all people to occupy, regardless of whether they are sleeping, playing, or working.
Bill McHugh, CSC, CSI, MBA, is executive director of the Firestop Contractors International Association (FCIA). He has been involved in Division 07 items since 1981, and in firestopping since 1990. McHugh has been FCIA executive director since the organization’s beginning in 1998. He has written, spoken, and moderated symposiums throughout North America and the Middle East. McHugh can be reached at firstname.lastname@example.org.
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