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Appendix A of TR 10 provides design tools for beams and columns of solid sawn,glulam or SCL materials under fire gn scenarios using the char calculation provisions of NDS ter 16.Table Al provides a method to quickly check if x§*hs ° a earn exposed on three sides passes the structural fire condition check provided the designer knows the beam's size and maximum demand to capacity ratio(R,) under the required non-fire condition using ASD load combinations. Table A2 provides a similar design table for columns exposed on all four sides. <" Thermal Separation In addition to establishing structural capacity of exposed wood members under fire conditions, a thermal separation check should be done when using the char depth calculation Photo Daum eames ARUP method.ASTM E119 requires wall and floor/roof assemblies to be checked for thermal separation wherein transmission of heat through the test specimen during the fire exposure Fire Performance of Nail-Laminated Timber period does not raise the average temperature on the Although it has been used in North American buildings for unexposed surface more than 250°F(139°C)above its many years, there has been a recent surge of interest in NLT initial temperature.AWC's TR 10 provides further discussion panels for floors, roofs and walls in mass timber buildings. on this as well as design equations for calculating thermal NLT is recognized in IBC Section 2304.9.3 as a permitted separation ratings for exposed timber assemblies. building material under the name mechanically-laminated decking. Its allowable use is similar to that for exposed, Fire Performance of Glued-Laminated Timber fire resistance-rated glulam. Chapter 16 of the NDS is a Mass timber projects often utilize exposed glulam columns valid option for calculating fire resistance of exposed NLT. and beams.These members are typically considered either However,consideration should be given to the entire NLT part of the building's primary structural frame or its floor/roof assembly; it is often combined with a monolithic topping truction,and require fire-resistance ratings per IBC Table layer to justify urn-directional char behavior,and recent .Glulam is recognized as a permitted building material fire testing has demonstrated the validity of this approach. in IBC Section 2303.1.3 when manufactured in accordance Recent E119 tests of NLT assemblies have shown fire- with ANSI/AITC A 190.1 and ASTM D3737. When required resistance ratings determined by testing to be significantly to have a fire-resistance rating,glulam bending members are longer than the three-sided char method for timber decking unique in that they require core laminations to be substituted in NDS Chapter 16 applied to NLT. For further discussion. for additional tension laminations in order to account for see the Nail-Laminated limber Design&Construction Guide, the loss of the lowest laminationls)due to charring in a fire, available at:httos:/iwwwthinkwood com/oroducts-and- NDS Section 16.2.4 requires the following: svttems/mass-timher/nitgu ode For structural glued-laminated timber bending members given in Table 5A and rated for 1-hour fire endurance, an outer tension lamination shall be substituted for a core '� - - ei c lamination on the tension side for un-balanced beams and on both sides for balanced beams. For structural glued h laminated timber bending members given in Table 5A and rated for I 1/2-or 2-hour fire endurance, two outer tension u laminations shall be substituted for two core laminations on the tension side for unbalanced beams and on both sides for balanced beams, When used as a flat floor or roof panel,the fire-resistance provisions for glulam would match those for NLT, noted in the • next section. l },. 41111 S • io