HomeMy WebLinkAboutBreak away Fire Release Connectors SpecsM FERO 15305-117 Avenue Edmonton, Alberta Canada T5M 3X4 DATE: RE: Submittal Letter - FERO Break -Away Fire -Release Connectors, PROJECT NAME Dear: [INSERT NAME] k. 780.455.5098 engineering@ferocorp.com www.ferocorp.com The 2012 IBC, section 706.2 requires that fire walls have sufficient stability under fire conditions to withstand collapse of construction on either side without collapse of the wall. The use of FERO Break -Away Fire - Release connectors is an acceptable engineering design approach to satisfy this code requirement. The use of break -away connectors is an established methodology in the design and construction of fire walls. As an example, the National Concrete Masonry Association (NCMA) TEK 5-8B specifically references the use of break -away connectors in the design of masonry fire walls, see Figure 3 in the attached copy of TEK 5-8B. As noted in the TEK document, the examples shown are not the only ones that will comply and are included as examples. Project specific needs will dictate the final detailing decisions. The FERO Breakaway connector uses a grooved nylon washer as its fusible member, which has a heat deflection temperature of 75°C at 1.82 MPa, and a maximum resistance to continuous heat of 120°C. The connector has been tested to withstand greater than 5 kN of lateral force, ensuring the structural integrity of the connection in non -fire conditions. Nylon has a known melting point of 260 degrees Celsius, which is much lower than the melting point of the supporting members. This ensures that, in the event of lateral stresses caused by deformation of such supporting members, the fusible washer will have softened or melted allowing for relief of such lateral members or, under extreme deformation, complete disengagement of the framing system. This allows the designing engineer to ensure the structural integrity of the firewall for the fire rated time, thereby satisfying the requirements of IBC Code 706.2. The concept of break -away anchors is valid regardless of the construction material of the fire wall (concrete masonry and poured concrete are the most common fire wall materials) and is applicable for both load bearing and non -load bearing walls. FERO Break -Away Fire -Release Connectors installed on the bearing side of the wall will insure that a collapse of the roof structure bearing on the wall will not compromise the structural stability of the firewall. FERO Breakaway connectors do not form part of the firewall itself, but rather form a connection to the firewall that is designed to permit the structure bearing on the fire side of the firewall to deform or collapse without compromising the structural integrity of the firewall. Because the product is external to the firewall and is designed to permit release of the structure from the firewall during a fire and prior to the fire rated time, a UL rating is not applicable to this product. Sincerely, Attachments: NCMA TEK 5-88 DETAILING CONCRETE MASONRY FIRE WALLS Keywords: architectural details, cantilevered fire wall, con- struction details, double fire wall, fire walls, fire -resistance rating, International Building Code, protected openings INTRODUCTION Concrete masonry, due to its inherent durability, reliability and superior fire resistance characteristics, is well suited to a range of fire protection applications. The International Building Code (IBC) (ref. 1) defines three wall types for fire protection— fire wall, fire barrier and fire partition—depending on the level of protection provided for the type of occupancy and intended use. Of the three defined fire -rated assemblies, a fire wall is generally considered to provide the highest level of robustness and fire safety. As such, it is intended to provide complete separation and must be structurally stable under fire conditions. Generally, fire barriers and fire partitions are required to provide the minimum protection necessary to assure that building occupants can evacuate a structure without suffering personal injury or loss of life. In addition to these requirements, fire walls reduce the likelihood of fire spread into the adjoining space, thus minimizing major property loss. Potentially significant architectural and economic advantages can be gained from using fire walls since each portion of a building separated by fire walls is considered a separate building for code compliance purposes. Designing and detailing fire walls is a complex task with many facets, including structural criteria, fire resistance, ver- tical and horizontal continuity, and criteria for protecting openings and joints. It is beyond the scope of this TEK to include every code provision and exception for fire wall design for all project conditions. While much of the informa- tion in this TEK is applicable to both the IBC and the NFPA 5000 (ref. 2) building codes, the provisions are based on the 2003 IBC, so certain provisions may be different from NFPA 5000 requirements. Hence, the information may or may not conform to local building code requirements and should be carefully reviewed to ensure compliance. In addition, the details shown here are not the only ones that will comply, but are included as examples. Project -specific needs will dictate the final detailing decisions. TEK5-8B © 2005 National Concrete Masonry Association (replaces TEK 5-8A) FIRE WALLS TEK 5-8B Details (2005) By Code (ref. 1), fire walls are required to have the minimumfire-resistance rating acceptable for the particular occupancy or use group which they separate and must also have protected openings and penetrations. A firewall must have both vertical and horizontal continuity to ensure that the fire does not travel over, under or around the fire wall. In addition, the wall must have sufficient structural stability under fire conditionsto remain standing for the duration of time indicated by the fire -resistance rating even with the collapse of construction on either side of the fire wall. Fire -Resistance Rating Because fire walls provide a complete separation between adjoining spaces, each portion of the structure separated by fire walls is considered to be a separate building. Fire walls in all but Type V construction must be constructed of approved noncombustible materials. Table 1 shows minimum required fire -resistance ratings. Information on determining the fire -resistance ratings of concrete masonry assemblies is contained inFireResistance Rating of Concrete Masonry Assemblies, TEK 7-lA and Standard Method for Determining Fire Resistance of Concrete and Masonry Construction Assemblies (refs. 3, 4). Table 1—Required Fire Wall Fire -Resistance Ratings (ref. 1) Group Fire -resistance rating, hr A, B, E, H-4, I, R-1, R-2, U F-1, H -3B, H-5, M, S-1 H-1, H-2 F-2, S-2, R-3, R-4 3A 3 4B 2 A Walls shall not be less than 2 -hour fire -resistance rated where separating buildings of Type II or V construction. B For Group H-1, H-2 or H-3 buildings, also see IBC Sections 415.4 and 415.5 Break -Away Firewall Connection System Description and Proof -of -Concept A Technical Article by Y. Korany, Ph.D., P.Eng. M. Hatzinikolas, Ph.D., P.Eng., FCSCE May, 2013 Table of Contents Executive Summary 1 Background 2 Description of the Break -Away Connector 4 Proof -of -Principal Testing 6 Summary and Conclusions 9 References 10 Appendix: Break -Away Connection System Details 11 i List of Figures Figure 1: Floor -to -Firewall Connection using a Break -away Connector 5 Figure 2: Support Member Detail 5 Figure 3: Test of a Fusible Member under Normal Service Conditions 6 Figure 4: Simulated Fire Test Set-up 7 Figure 5: Progression of Test under a Simulated Fire Scenario 7 ii Executive Summary One of the main requirements for structural integrity of firewalls under the National Building Code of Canada is that structural components should be connected to firewalls in such a way that a failing structural member may collapse without causing any damage to the firewall. As a result, firefighters would have more time to prevent the spread of fire to adjacent spaces. In some cases, occupants in an adjacent room/structure would be provided with sufficient time to escape before the firewall is compromised and the fire spreads to the adjacent space. The connection system developed by FERO Corporation consists of a support member and a fusible member and can be used to connect a floor or ceiling structural member to a firewall. The fusible member has a lower melting point than the support member. This break -away connector differs from conventional connectors by the use of a slotted support member that allows for movement and total disengagement of the structural member caused by the melting of a fusible member in the event of a fire. This article describes the developed break -away firewall connector in detail, including the results of the "proof -of -principle" testing that was performed at FERO Corporation Laboratory. The connector performs similar to a conventional connector under normal service situations (no fire), and effectively allows for disengagement of structural members during fire as required. 1 Background In residential, commercial and industrial structures, it is desirable to have members that are designed to slow or prevent the spread of fire between adjacent spaces. These members are typically firewalls which are designed and/or treated to resist combustion and prevent rapid heat transfer. Most commonly, firewalls are substantially vertical partitions that define interior spaces such as individual rooms within the same structure, or interior spaces of separate, adjacent structures. Firewalls are required for containing and limiting the effects of fires within buildings, in such a way that allows for better access to the burning sections of a building, allows for sufficient escape time to the occupants, and minimizes the damage caused by fire spreading throughout the building. Firewalls could be loadbearing structural components of the building. In some multi-level buildings, structural members are supported by at least one firewall. Commonly, horizontal structural components such as floors or ceilings are tied into at least one substantially vertical firewall. In the event that a heat -inducing event occurs within an interior space that is at least partially defined by a firewall, it is desirable for structural members to be releasable from the firewall. If a structural member catches fire, it is beneficial to release the structural member from the firewall to separate the heat source from the firewall. This release can allow the firewall to remain intact for a longer duration. As a result, firefighters would have sufficient time to prevent the spread of fire to adjacent spaces. In some cases, occupants in an adjacent room/structure would be provided with sufficient time to escape before the firewall is compromised and the fire spreads to the adjacent space. The National Building Code of Canada (NBCC) [1] article 3.1.10.1 specifies that "connections and supports for structural framing members that are connected to or supported on a firewall ... shall be designed so that the failure of the framing systems during a fire will not affect the integrity of the firewall during the fire." The NBCC Structural Commentary C (Structural Integrity of Firewalls) paragraph 15 suggests a design approach that satisfies the requirements of structural integrity of firewalls under the NBCC by incorporating the use of a weak -link connection of structural components to the firewall in such a way that a failing structural member may collapse without causing any damage to the firewall. 2 FERO Corporation has developed a firewall connection system that employs this weak -link concept to connect common structural framing elements to firewalls [2]. In the event of a fire, a fusible element in the connection softens and melts, allowing for the displacement and ultimately the disengagement of the connecting element as it fails, which protects the firewall from any increased stresses that may occur as the connected element becomes damaged during the fire. Such a system is desirable for maintaining the integrity of the firewall, allowing for a greater building and occupant safety during fires and a longer time to evacuate. The use of fusible elements in structural design is not uncommon. Fusible members have been used to allow displacements in structural members to relieve stresses and allow for displacements caused by fires [3, 4]. It was reported that the structure behaves normally until there is a fire, at which point any additional stresses that are developed as a result of the fire may be dissipated by the flexibility created due to the loss of the fusible members. In timber firewall construction, aluminum clips with a relatively low melting point are commercially available which allow structural members to disengage from a firewall in the event of a fire [5]. Similarly, break away firewall anchors are commercially available for masonry firewalls, using a zinc alloy or a similar material [6]. In all of these connector systems, the connector is designed to melt in its entirety during a fire, causing the collapse of the structural framing element solely due to heat, regardless of whether or not this disengagement is structurally necessary. This article describes the developed break -away firewall connector in detail, including the results of the "proof -of -principle" tests that were performed at FERO Corporation Laboratory. The break -away connector performs similar to a conventional connector under normal service situations (no fire), and effectively allows for disengagement of structural members during fires as required. 3 Description of the Break -Away Connector The connection system developed by FERO Corporation consists of: a) a support member connectable to the firewall for securing a floor or ceiling to the firewall and b) a fusible member having a lower melting point than the support member, and can be used to connect a floor or ceiling structural support to a firewall. This break -away connector differs from conventional structural -to -masonry connectors by the use of a slotted support member that allows for movement or total disengagement of the structural member caused by the melting of a fusible member in the event of a fire. Another advantage of this design is that the support member may provide support for a structural member under normal conditions. Accordingly, the load bearing capacity the break -away connector system is not limited by the load bearing capacity of the fusible member itself. A schematic of a floor -to -firewall connection using the break -away connector is shown in Figure 1. The structural component of the floor (1) is connected to a masonry firewall by a support member (2) that is bolted to the firewall. The support member contains slots (see Figure 2) which allow for the movement of the connecting bolts (4) when the fusible member (3) is softened or melted during a fire. The movement of the bolts allowed by the slots will relieve lateral stresses caused by the deformation of the framing system in a fire event, and under extreme deformations will allow the framing system to disengage completely. The fusible member is made of Nylon having a melting point of approximately 260 °C, which is much lower than the support member's melting point to ensure that the failure mode of the connector as a whole can be anticipated accurately. Nylon, a semi -crystalline plastic, is commonly used in commercial products, and generally has high chemical resistance. Nylon has a heat deflection temperature of 75 °C at 1.82 MPa, and a maximum resistance to continuous heat of 120 °C, allowing for satisfactory connection performance up to the point of fire [7]. 4 Figure 1: Floor -to -Firewall Connection using a Break -away Connector Figure 2: Support Member Detail 5 Proof -of -Principal Testing It is crucial to the integrity of the connection that the fusible member does not fail until it is subjected to fire conditions. In order to validate this requirement, the lateral resistance provided by the break -away connector was tested as shown in Figure 3, where increasing loads were added to test the resistance of the plate to bolts being loaded in shear. The test was continued until a total load of 1,460 pounds (6.5 kN) was applied, at which point there were no signs of movement or failure occurring in the tested connector. The break -away firewall connector system was also tested in a simulated fire scenario. A transverse load of 110 pounds (0.5 kN) was applied to the OWSJ structural frame while a blowtorch was used to supply heat to the connector as shown in Figure 4. a) Test Set-up b) Detail of Member Connection Figure 3: Test of a Fusible Member under Normal Service Conditions 6 Figure 4: Simulated Fire Test Set-up Several tests of the connectors under extreme heat were performed, with a time to failure ranging between three and four minutes from the onset of the test. The behaviour during one of the tests is shown in Figure 5 where an OWSJ was connected to a firewall using a break- away connector. a) Beginning of Test b) Rotation of Joist c) Collapse of Fusible Member Figure 5: Progression of Test under a Simulated Fire Scenario 7 Figure 5(a) shows the set-up at the beginning of the test, with a 10 mm fusible member placed at the bottom of the connection assembly. Following the direct application of heat for approximately two minutes, the softening of the fusible member allowed for some displacement in the connection, including noticeable rotation of the structural member as shown in Figure 5(b). Further application of heat resulted in the total failure of the fusible member as shown in Figure 5(c), followed shortly by the disengagement of the structural member from the connection. Tests were performed using various thicknesses for the fusible member. It was noted that a thickness of 20 mm, double the thickness shown in Figure 5, allowed more room for the structural member to rotate before disengaging, which resulted in a smoother release of the structural member. The time required for failure is not expected to be representative of the time that would be taken in a real fire, as the blowtorch applied a more intense heat than would naturally occur. Instead, the tests act as a "proof -of -principle", where the fusible material has been shown to melt away given sufficient heat. At the end of the test, the support member remained attached to the test wall with no visible signs of damage. It is anticipated that during a real fire, the connector would continue to provide sufficient vertical support to any attached structural components. In the event that the fire was strong enough to melt the fusible member of the connector, but the structural component itself was undamaged, it is expected that this connection would only require retrofitting following the fire, unlike several of the other connectors currently available on the market [6]. This provides a significant advantage as disengagement of the structural system will only occur when it is required in order to prevent damage to the firewall, thus minimizing the risk of incidental damage caused by premature disengagement. The combination of the different types of tests performed on the break -away firewall connector demonstrate that the connector behaves similar to typical connectors under normal conditions by resisting both vertical and horizontal forces, but under fire conditions it releases the structural member from the firewall after sufficient exposure to heat. 8 Summary and Conclusions In order for firewalls to perform as effectively as possible, they must restrain the spread of fires while continuing to function as crucial components to the building. Due to these requirements, the National Building Code of Canada (NBCC) specifies that the failure of any structural components connected to a firewall must not damage the firewall itself. FERO Corporation has developed and patented a break -away connector for connecting horizontal structural components, such as joists of floor and roof systems, to firewalls in such a way that meets the requirements of the NBCC. Through the use of a fusible member, the connector allows for displacement and complete disengagement of the structural component from the wall during a fire before any significant damage could happen in the firewall itself. FERO break -away connection system satisfies the requirements of the National Building Code of Canada to preserve the integrity of a firewall during a fire, while continuing to act as a strong connection and without failing prematurely. Unlike other break -away connectors currently on the market, this connector uses a simple design that relies on only one part of the connector failing during the fire. This allows for disengagement of the structural component to occur only when required to prevent damage to the firewall, and not earlier. Other systems currently available on the market are made entirely from a fusible material. The behavior of the break -away firewall connector has been confirmed through testing in both the absence and presence of a fire. The connection demonstrates significant resistance in the absence of fire, allowing it to behave predictably and be used in conventional design. However, in the presence of a fire, the break -away firewall connector will allow for displacement and disengagement of the structural component as desired. Experimental testing demonstrated that a fusible member with a thickness of 20 mm allowed enough room for the structural member to rotate before disengaging, which resulted in a smoother release of the structural member. The support member remained attached to the test wall with no visible signs of damage. It is anticipated that during a real fire, the connector would continue to provide sufficient vertical support to any attached structural components. 9 References 1. Canadian Commission on Building and Fire Codes (2010). National Building Code of Canada. National Research Council of Canada, Ottawa, Canada. 1,245 pp. 2. Hatzinikolas, M. (2012). Break Away Firewall Connection System and a Method for Construction. US Patent 2012/0279143, Washington, DC: US Patent and Trademark Office. 3. Bailey, M., Downer, J.C. (1973). Ceiling System. US Patent 3,708,932, Washington, DC: US Patent and Trademark Office. 4. Platt, W.J., Lin, Y. (2009). Hook Connector with Plastic Fire Relief. US Patent 7,520,095, Washington, DC: US Patent and Trademark Office. 5. Clark Dietrich Area Separation Wall Systems. Online source, URL: http : //www. clarkdietrich. com/products/area-separation-wall/clarkdietrich-area- separation-wall-systems, accessed April 2013. 6. Heckmann Building Products, Inc. Break -Away Firewall Anchors. Online source, URL: http://www.heckmannbuildingprods.com/Firewall_Anchors.html, accessed April 2013. 7. Weast, R.C. Editor -in -Chief. (2012). CRC Handbook of Chemistry and Physics, 93rd Edition. CRC Press, Boca Raton, Florida, USA. 10 Appendix: Break -Away Connection System Details 11 Front View Seale 4" = 1' Top View Scale 4" = 1' Sec. 1 Scale 4" = 1' Firewall Connector Detail Side View Scale 4.' = 1' FERO Corporation 15305 -117th Ave., Edmonton, Alberta, T5M 3X4, Canada Tel: (780) 455-5098 Fax: (780) 452-5968 www.ferocorp.com E—mail: engineering©ferocorp.com FERO Firewall Connector Detail FERO Corporation 15305 -117th Ave., Edmonton, Alberta, T5M 3X4, Canada Tel: (780) 455-5098 Fax: (780) 452-5968 www.ferocorp.com E—mail: engineering©ferocorp.com FERO FIREWALL --Y -____ -L STEEL ANGLE AS PER DESIGN /1 STEEL BEAM AS PER DESIGN ANCHOR BOLT FIREWALL CONNECTOR PER DESIGN BOLT WASHER TO COLLAPSE IN CASE OF FIRE STEEL COLUMN AS PER DESIGN Firewall Connector Lateral Support Detail Connector Size per Design Scale 3" = 1' Detail SIB - 1 - 04 FERO Engineering 15305 -117th Ave., Edmonton, Alberta, T5M 3X4, Canada Tel: (780) 455-5098 Fax: (780) 452-5969 www.ferocorp.com E—mail: engineering@ferocorp.com 11 FERO • STEEL ANGLE AS PER DESIGN r To II / Firewall Connector Beam Support Detail STEEL BEAM AS PER DESIGN ANCHOR BOLT FIREWALL CONNECTOR BOLT WASHER TO COLLAPSE IN CASE OF FIRE Connector Size per Design Scale 3" = 1' Detail SIB - 1 - 04 FERO Engineering 15305 -117th Ave., Edmonton, Alberta, T5M 3X4, Canada Tel: (780) 455-5098 Fax: (780) 452-5969 www.ferocorp.com E—mail: engineering@ferocorp.com 11 FERO Firewall Connector Joist Support Detail Connector Size per Design Scale 3" = 1' Detail SIB - 1 - 04 FERO Engineering 15305 -117th Ave., Edmonton, Alberta, T5M 3X4, Canada Tel: (780) 455-5098 Fax: (780) 452-5969 www.ferocorp.com E—mail: engineering@ferocorp.com 11 FERO 1-1REWALL Yr )• FIREWALL CONNECTOR ANCHOR BOLT STEEL ANGLE AS PER DESIGN I BOLT A ii WASHER 6 C0 .APSE IN CASE OF FIRE Firewall Connector Joist Support Detail Connector Size per Design Scale 3" = 1' Detail SIB - 1 - 04 FERO Engineering 15305 -117th Ave., Edmonton, Alberta, T5M 3X4, Canada Tel: (780) 455-5098 Fax: (780) 452-5969 www.ferocorp.com E—mail: engineering@ferocorp.com 11 FERO Protected Openings and Penetrations The IBC states that fire walls must have closures such as fire doors or shutters which automatically activate to secure the opening in the event of a fire. Further, openings in fire walls are restricted to a maximum size of 120 ft? (11.2 n). An exception permits larger openings provided both buildings separated by the fire wall are equipped throughout with automatic sprinkler systems. In all cases, the aggregate width of all openings at any floor level is limited to 25 percent of the wall length. Through -penetrations in fire walls must utilize either fire -resistance -rated assemblies or a firestop system which is tested in accordance with either ASTM E 814 (ref. 5) or UL 1479 (ref. 6). The annular space between steel, iron or copper pipes or steel conduits and surrounding concrete masonry fire walls may be filled with concrete, grout or mortar for the thickness required to provide a fire -resistance rating equivalent to the fire -resistance rating of the wall penetrated. In addition, the penetrating item is limited to a 6 -in. (152 -mm) nominal diameter and the opening is limited to 144 in? (92,900 mm2). Openings for steel electrical outlet boxes are permitted provided they meet the Code - specified requirements. Combustible members, such as wood, are permitted to be framed into concrete masonry fire walls provided that, when framed on both sides of the wall, there is at least 4 in. (102 mm) between the embedded ends of the wood framing. The full thickness of the fire wall 4 in. (102 mm) above and below, as well as in between, the combustible member must be filled with noncombustible materials approved for fireblocking. Voids created at the junction of walls and floor/ceiling/ roof assemblies must be protected from fire passage by using fire-resistant joint systems tested in accordance with ASTM E 1966 or UL 2079 (refs. 7, 8). Control joints in fire walls must have fire -resistance ratings equal to or exceeding the required rating of the wall. Recommendations for locating and spacing control joints in concrete masonry walls also apply to concrete masonry fire walls. Control Joints for Concrete Masonry Walls, TEK 10-2B (ref. 9) includes control joint spacing criteria and illustrates control joint details for various fire -resistance ratings. Vertical and Horizontal Continuity The IBC mandates vertical continuity of a fire wall by requiring that the wall extend continuously from the foundation to a termination point at least 30 in. (762 mm) above both adjacent roofs. Exceptions permitting the fire wall termination at the underside of the roof deck or slab are listed in the Code. These exceptions require the use of Class B roof coverings (minimum), no openings within 4 ft (1.22 m) of the fire wall and other criteria for roof assembly protection. Buildings located over parking garages and stepped buildings are subject to additional requirements and permitted exceptions. Horizontal continuity limits the spread of fire around the ends of a fire wall. The IBC requires that fire walls be continuous from exterior wall to exterior wall and that they extend at least 18 in. (457 mm) beyond the exterior surface of exterior walls. As with the vertical continuity requirements, there are criteria for terminating the fire wall at the interior surface of an exterior wall based on the types and fire -resistance ratings of the intersecting wall constructions and on the presence of an automatic sprinkler system installed per Code requirements. Structural Stability Under Fire Conditions While concrete masonry remains structurally stable during the extreme temperatures experienced under fire conditions, steel framing undergoes a reduction in strength as the surrounding temperature and duration of exposure are increased. This decreased structural capacity is evidenced by a dramatic increase in the deflection and twisting of steel members. Wood framing may burn, collapse, shrink and/or deform under fire exposure and it too loses its load -carrying capability. For these reasons, concrete masonry fire walls should be designed and detailed to withstand any loading imposed by fire -compromised framing systems or detailed so that those loads are not imparted to the fire wall during a fire. This is perhaps the most difficult detailing provision in fire wall design. DETAILING CONSIDERATIONS FOR STRUCTURAL STABILITY Because most fire wall criteria relating to fire -resistance rating, protected openings and penetrations, and vertical and horizontal continuity are prescriptive, the designer's primary challenge when engineering and detailing a concrete masonry fire wall relates to maintaining the structural Grout Joint reinforcement s required Vertical reinforcement anchored in foundation Concrete masonry pilaster Concrete masonry fire wall Figure 1—Freestanding or Cantilevered Fire Wall with Pilaster stability of the wall under fire conditions. There are various methods of designing, detailing and constructing fire walls for structural stability during a fire. Among the systems recommended for use as fire walls are: (a) cantilevered or freestanding walls, (b) laterally supported and tied walls, and (c) double wall construction. Cantilevered or Freestanding Walls Cantilevered walls (Figure 1) do not depend on the roof framing for structural support. The wall is cantilevered from the foundation by grouting and reinforcing, or by prestressing. Freestanding walls may also be designed to span horizontally between pilasters or masonry columns integral to the wall. It can be difficult to design a cantilevered single wythe loadbearing fire wall. Thermal stresses may cause deformation in steel or wood joists or framing systems which can eccentrically load the top of the fire wall. Designing the wall to remain stable under that loading condition may be difficult especially for tall or slender walls. For this reason, cantilevered single wythe fire walls are often designed as nonbearing walls with the primary roof framing system running parallel to the fire wall. Column lines on either side of the wall support the roof framing. Details for cantilevered/freestanding fire walls are similar to those for laterally supported walls (shown in Figures 2, 3 and 4) with the exception that cantilevered walls do not include through -wall ties or break -away connectors. Laterally Supported or Tied Walls Laterally supported or tied walls rely on the building frame for lateral stability. The fire wall is laterally supported on each side by the framing system. As such, forces Table 2—Minimum Clearance Between Structural Steel and Fire Wall (ref . 10) Length of bay perpendicular to fire wall ft. (m) Minimum clearance "X" between wall and steel, in. (cm) 20 (6.1) 25 (7.6) 30 (9.1) 35 (10.7) 40 (12.2) 45 (13.7) 50 (15.2) 55 (16.8) > 60 (18.3) 2 1/2 3 1/4 3 3/4 4 1/2 5 5 3/4 6 1/4 7 7 1/2 (6.4) (8.3) (9.5) (11.4) (12.7) (14.6) (15.9) (17.8) (19.1) due to the collapse of the structure on one side of the fire wall are resisted by the structural framework on the other side of the wall. Adequate clearance, as listed in Table 2, between the framing and the concrete masonry fire wall is necessary to allow framing expansion or deformation with- out exerting undue pressure on the wall. Laterally supported fire walls may utilize break -away connectors manufactured with metals having melting points lower than structural steel (generally about 800° F (427° C)), so that, in the event of fire, the connectors on the fire side of the wall will give way before those on the non -fire side. In Figures 2 and 3, the structural diaphragm on the side of the wall opposite the fire provides the stability. The connections between the roof and wall must be designed to resist these forces. If the diaphragms occur at different elevations, the wall must be designed to withstand the anticipated flexural forces that will be generated as well. Figure 4 shows a laterally supported fire wall with combustible framing supported by metal joist hangers. Joist hanger manufacturers may have alternate details as well. Note that there may be code limitations on the use of combustible framing. Figure 5 shows design and detailing options for tied fire walls. Tied fire walls are a type of laterally supported fire wall where the roof structure is not supported by the fire wall, but rather by the roof structure on the other side Parapet Fire stop material (not shown for clarity) between and around ends of joists Noncombustible roof deck with ,z— Class B roof covering2 Bond beam Concrete masonry unit rated for fire exposure reinforced as required Steel bar joist each side' Notes: 1. Joists may be aligned if bond beam width permits proper installation of firestop material between joist ends. Stagger joists (as shown) as necessary. 2. 30 in. (762 mm) parapet is required unless all conditions are met: a) roof deck is noncombustible; b) roof covering is Class B (minimum); and c) no openings within 4 ft (1.22 m) of fire wall. 3. Top chord bearing wood joists similar. Figure 2—Laterally Supported Loadbearing Fire Wall of the fire wall, thus the two roof structures are tied together across the fire wall. Figure 5a illustrates one choice for a "double column" detail which uses a through -wall tie to connect the primary steel on both sides of the fire wall. In this detail, the primary roof framing steel is parallel to the fire wall and supported on fireproofed columns. One column is used on each side of the fire wall to support the roof system for that building. Both steel columns and primary support beams/trusses should be aligned vertically and horizontally with the columns and beams/trusses on the opposite side of the wall and should be fireproofed. If the primary steel is not parallel to the fire wall Figure 5b shows a through -wall tie which can be used. As an alternative to using two steel columns, Figure 5c shows one steel support column encased entirely within the concrete masonry fire wall. Fire protection requirements for steel columns are included inSteel Column Fire Protection, TEK 7-6 (ref. 11). This system creates a single column line tied at the top of the wall to horizontal roof framing. Detailing the connection of the steel beams to the concrete masonry fire wall varies based on the framing layout, but the wall must be supported at the top and the connection must be fire protected. Double Wall Fire Wall Double wall construction (Figure 6) is generally easy to design and detail for loadbearing conditions, especially for taller walls. It utilizes two independent concrete masonry walls side by side, each meeting the required fire -resistance rating. In the event one wall is pulled down due to fire, the other wall remains intact, preventing fire spread. Floor and roof connections to each fire wall are the same as for conventional concrete masonry construction. These walls are often cantilevered or freestanding but may be tied or laterally supported as well if so detailed and designed. This system is also easy to use when a building addition requires a fire wall between the existing structure and the new construction. Grout, as required Break -away connector each side Vertical reinforcement, as required Steel bar joist "X" each side see Table 2 Concrete masonry) fire wall J L. Steel column each side Note: If detailed without breakaway connectors, fire wall would be nonloadbearing freestanding or cantilevered. Figure 3—Laterally Supported Nonloadbearing Fire Wall /— Parapet Fill full thickness of fire wall 4 in. (102 mm) above, below and between wood members with noncombustible fire blocking Concrete masonry rated for fire exposure, reinforced as required Joist hangers bolted to concrete masonry Note: Fire proofing (if required) not shown for clarity. Check with local building codes for fire rating requirements on wood truss and hanger assemblies. Figure 4—Laterally Supported Loadbearing Fire Wall: Wood Framing - Secondary steel "X" both sides, J see Table 2 Primary steel . ■i i \i„ Concrete masonry fire wall Note: Beams and columns require fireproofing, not shown for clarity. Figure 5a—Double Column Method, Through -Wall Tie Detail: Primary Steel Parallel to Fire Wall Steel bea "X" both sides, see Table 2 Concrete masonry fire wall Angle clip, weld to beam A Angle clip, weld to beam Provide clearance Note: Beams and columns require fireproofing, not shown for clarity. Figure 5b—Double Column Method, Through -Wall Tie Detail: Primary Steel Perpendicular to Fire Wall Masonry encases steel per building code A Steel column encased in fire wall Concrete slab VA VA %• 30 in. (762 mm) min. concrete masonry parapet r A Steel beam framing into cross beam supported on steel column s rr H Section A - A Concrete masonry fire wall Figure 5c—Single Column Method Figure 5—Tied Fire Walls (ref. 10) REFERENCES 1. International Building Code 2003. International Code Council, 2003. 2. Building Construction and Safety Code - 2003 Edition, NFPA 5000. National Fire Protection Association, 2003. 3. Fire Resistance Rating of Concrete Masonry Assemblies, NCMA TEK 7-1A. National Concrete Masonry Association, 2003. 4. Standard Method for Determining Fire Resistance of Concrete and Masonry Construction Assemblies, ACI 216.1-97/ TMS 0216-97. American Concrete Institute and The Masonry Society, 1997. 5. Standard Test Method for Fire Tests of Through -Penetration Fire Stops, ASTM E 814-02. ASTM International, 2002. 6. Fire Tests of Through -Penetration Firestops, UL 1479. Underwriters Laboratory, 2003. 7. Standard Test Method for Fire -Resistive Joint Systems, ASTM E 1966-01. ASTM International, 2001. 8. Tests for Fire Resistance ofBuilding Joint Systems, UL 2079. Underwriters Laboratory, 2004 9. Control Joints for Concrete Masonry Walls -Empirical Method, NCMA TEK 10-2B. National Concrete Masonry Association, 2005. 10. Criteria for Maximum Foreseeable Loss Fire Walls and Space Separation, Property Loss Prevention Data Sheets 1-22. Factory Mutual Insurance Company, 2000. 11. Steel Column Fire Protection, NCMA TEK 7-6. National Concrete Masonry Association, 2003. Wood nailer anchored to one wall Sheet metal coping cap with continous cleat each side Attachment strip Counter flashing Grout cores solid at anchor bolts and reinforcement Seal ant Cant Parapet flashing Grout stop if wall below not grouted Steel bar Joist welded or bolted to bearing plate Figure 6 -Double Fire Wall Disclaimer: Although care has been taken to ensure the enclosed information is as accurate and complete as possible, NCMA does not assume responsibility for errors or omissions resulting from the use of this TEK. NATIONAL CONCRETE MASONRY ASSOCIATION 13750 Sunrise Valley Drive, Herndon, Virginia 20171 www.ncma.org To order a complete TEK Manual or TEK Index, contact NCMA Publications (703) 713-1900 IN FERO BREAK -AWAY FIRE -RELEASE CONNECTORS MAINTAIN FIREWALL INTEGRITY EXTEND FIRE ESCAPE TIMES 1. FERO BREAK -AWAY FIRE -RELEASE CONNECTORS FERO Break -Away Fire -Release Connectors are designed to meet the National Building Code of Canada requirement that in the event of a fire a failing structural member may collapse without causing damage to the firewall. COMPONENTS This innovative break -away connector differs from conventional connectors by the use of a slotted support angle that allows for movement and total disengagement of the failing structural member caused by the melting of the fusible washer in the event of a fire. Unlike other available fire release systems, the support angle of our system functions as a structural member under normal service conditions. Accordingly, the load bearing capacity of FERO Break -Away Fire -Release Connector is not limited by the load bearing capacity of the fusible washer. FIG. 1 - Joist Support Details- Spacing and size of angle as specified by project engineer. FIREWALL STEEL I -BEAM COLLAPSIBLE WASHER BRAWAY CHORE T P FIREWAC FIG. 2 — Beam Support Detail. For lateral support of the firewall FERO Break -Away Fire -Release Connector: - delays or prevents the collapse of firewalls in the event of a fire - increases the fire escape time for occupants and firefighters - minimizes the damage caused by fire - maintains the structural capacity of the connection under normal service conditions. FERO BREAK -AWAY FIRE -RELEASE CONNECTORS INSTALLATION FERO Break -Away Fire -Release Connectors consist of: a) a support steel angle connected to the firewall for securing a floor or ceiling to the firewall and b) a fusible washer with a lower melting point than the support angle. The surface of the angle in contact with the washer is grooved for maximum lateral load resistance under normal conditions. The fusible washer is made of Nylon having a melting point of approximately 260°C, which is much lower than that for the steel support angle. Nylon is commonly used in commercial products and generally has high chemical resistance. It has a heat deflection temperature of 75°C at 1.82 MPa, and a maximum resistance to continuous heat of 120°C, ensuring a satisfactory performance up to the point of fire. The floor framing members are connected to the masonry firewall by a slotted steel angle that is bolted to the firewall. A fusible washer is placed between the nuts of the bolts securing the framing members and the steel angle. The slots in the angle allow for the movement of the floor framing when the fusible washer is softened or melted during a fire. This movement relieves the lateral stresses caused by the deformation of the framing members in a fire event, and under extreme deformations allows the framing members to disengage from the firewall. It is beneficial to release the affected structural member from the firewall to separate the heat source from the firewall. This release allows the firewall to remain intact for a longer duration. As a result, firefighters would have sufficient time to prevent the spread of fire to adjacent spaces and occupants would be provided with sufficient time to escape before the firewall is compromised and the fire spreads. FIG 3 — Connector Details Other manufacturers have attempted to develop fire release systems. However, in all these systems, the anchor/connector is designed to melt in its entirety during a fire, causing total collapse of the struc- tural framing solely due to heat, regardless of whether or not this is necessary to protect the firewall. Another major disadvantage of these systems manufactured by others is that, unlike FERO's system, the structural capacity of their support members is limited because the entire system is made of a material of low melting point. FERO BREAK -AWAY FIRE -RELEASE CONNECTORS TECHNICAL INFORMATION Pre-engineered 152 mm long (6 inch) FERO Break -Away Fire -Release Connector is able to resist ultimate/factored loads from the flooring system up to the values given in TABLE 1. TABLE 1 — DESIGN INFORMATION 1 Angle Dimensions (mm) Vertical Resistance Pr (kN)5 Bolt Diameter (mm) Washer' Dimensions (mm) Douter Dinner tW Lateral Resistance Vr (kN)5'6 Angle Configuration 12 ta3 7.9 3.5 9.5 5.2 127 13 9.9 111106 16 15.4 19 21.7 19 38 19 10.6 10.0 9.5 4.3 152 13 8.2 �11._1` 16 12.6 19 18.1-, 203 13 6.0 1. Table values are the maximum vertical and lateral loads resisted by a support angle made of steel with a yield stress equal to 245 MPa. These values are for a discrete 150 mm (6 inch) long angle with two (2) slots and washers as shown in FIG 4 below. Longer and/or continuous angles with more than two slots are able to resist higher loads. 2. Dimension is for the horizontal leg of the angle. 3. Angle thickness has been reduced in calculations by 10% to account for surface roughening. 4. Washer's material has the following properties: Compressive Strength of 100 MPa, Compressive Modulus of 2.9 GPa, and a coefficient of friction with steel of 0.4. 5. The maximum vertical and lateral resistances are based on the ultimate limit states design approach assuming the bolts used secure the connection to be 3/ inch in size (19 mm) and made of grade 4.6 (Fy = 248 MPa and Fu = 413 MPa). 6. Angle size does not change the value of the lateral load as it is governed by the slip resistance between the washer and steel angle. A —44.45—. 25.40 8 0 g X44.45—. 25.40 152 152 FIG 4 — ANGLE FOR TABLE 1 .1- ORDERING SPECIFICATIONS When ordering please forward the following specifications from the structural designer: A: Bolt diameter B: Distance between centers (if dual bolts required) C: Distance between OWSJ D: Material thickness See: "Specifications and Ordering," for complete details. Im FERO 15305 -117 Avenue, Edmonton Alberta, Canada T5M 3X4 TEL: (780) 455-5098 www.ferocorp.com E-mail: info@ferocorp.com FAX: (780) 452-5969 PRINTED IN CANADA MEMBER OF THE BETTER BUSINESS BUREAU FERO BREAK -AWAY FIRE -RELEASE CONNECTORS FERO BREAK -AWAY FIRE -RELEASE CONNECTORS SPECIFICATIONS AND ORDERING When ordering please forward the following specifications from the structural designer: *Material thickness' available - 1/4" (6.35mm), 1/2" (12.7mm) & 5/8" (16mm). If specifying Custom Connectors - use the column provided. For load bearing, adjust the width** to accommodate your load requirements. Standard Connector for Lateral Support Meltable Plastic Component 1111111111111111 IIIIIIIIIIIIIIIIIIIIII SL Sharp Grooves to Engage Meltable Plastic Component T MHO - Mounting Hole Offset MHD - Mounting Hole Diameter Dimension Inch Custom L - Length W - Width" W - Width 2" T -Thickness" H - Height 2" T -Thickness" SS - Slot Separation SL - Slot Length MHO - Mounting Hole Offset SW - Slot Width 0.29" Order Quantity MHO - Hole Offset 1" MHD - Hole Diameter 0.29" Order Quantity Inverted Connector for Lateral Support illellip This Connector can also be rotated 180° to be used at the top of a supported member (see reverse). 11111111 SL MHO - Mounting Hole Offset Minimum 1" Clearance Required MHD - Mounting Hole Diameter Dimension Inch Custom L - Length W - Width" W - Width 2" T -Thickness" H - Height 2" T - Thickness* SS - Slot Separation SL - Slot Length MHO - Mounting Hole Offset SW - Slot Width 0.29" Order Quantity MHO - Hole Offset 1" MHD - Hole Diameter 0.29" Order Quantity Dual Load Bearing Connector 1 -I I� MHO - Mounting Hole Offset MHD - Mounting Hole Diameter 1 SL Dimension Inch L - Length W - Width" H - Height T -Thickness" SL - Slot Length SW - Slot Width SS - Slot Separation MHO - Mounting Hole Offset MHD - Mounting Hole Diameter Order Quantity Dual Inverted Load Bearing Connector + MHO - Mounting Hole Offset 1 Minimum 1" Clearance Required I MHD - Mounting Hole Diameter This Connector can also be rotated 180° to be used at the top of a supported member (see reverse). Dimension Inch L - Length W - Width"" H - Height T - Thickness" SL - Slot Length SW - Slot Width SS - Slot Separation MHO - Mounting Hole Offset MHD - Mounting Hole Diameter Order Quantity SEE REVERSE FOR ADDITIONAL TECHNICAL INFORMATION 1. FERO BREAK -AWAY FIRE -RELEASE CONTINUOUS ROOF & FLOOR ANGLES SPECIFICATIONS AND ORDERING Standard Roof Angle SL SE Inverted Floor Angle ft SW SL ALL SPECIFICATIONS to be specified by pro'ect engineer. NOTE: Continuous Roof and Floor Angles are Fully Customizable MHO: Mounting Hole Offset - minimum 1 in. from top for bolt and meltable washer SS: Slot Separation - also distance between OWSJ W: Width of Angle -10 ft is the most cost effective - longer angles available by request T: Thickness -1/2 in. & 5/8 in. also available Fero Break -Away Fire Release Connectors are to be installed under the following conditions: 1) The meltable washer must be exposed to the heat source, 2) the meltable washer must be in full contact with the grooves on the connector. Dimensions mm Standard MHD L: Length 4 i H MHO �T 4 in L L -IT Inverted Floor Angle ft SW SL ALL SPECIFICATIONS to be specified by pro'ect engineer. NOTE: Continuous Roof and Floor Angles are Fully Customizable MHO: Mounting Hole Offset - minimum 1 in. from top for bolt and meltable washer SS: Slot Separation - also distance between OWSJ W: Width of Angle -10 ft is the most cost effective - longer angles available by request T: Thickness -1/2 in. & 5/8 in. also available Fero Break -Away Fire Release Connectors are to be installed under the following conditions: 1) The meltable washer must be exposed to the heat source, 2) the meltable washer must be in full contact with the grooves on the connector. Dimensions mm Standard Custom L: Length 4 i H: Height 4 in T: Thickness 0.25 in W: Width 10 ft SW: Slot Width 0.29 in SL: Slot Length SS: Slot Separation SE: Slot to Edge HS: Hole Separation HE: Hole to Edge MHD: Mounting Hole Diameter 0.29 in MHO: Mounting Hole Offset Roof Angle Qty. Floor Angle Qty. 15305 -117 Avenue NW, Edmonton, Alberta, Canada T5M 3X4 TEL: (780) 455-5098 FAX: (780) 452-5969 Toll Free Technical Support call: 1-877-703-4463 www.ferocorp.com E-mail: info@ferocorp.com