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<br /> - � � figure 2 Lateral Force Bracing (figures 2 and 3) � N
<br /> Lateral force Bracing
<br /> SUSPENDED CEILINGS • - . • . . , • Ceiiings constructed of screw-or-nail-attached gypsum board on W
<br /> 4O1 - ` j one level that are surrounded by and connected to walls or soffits ''1
<br /> 's°°"e55 � ' that are laterally braced to the structure above are exempt from
<br /> � - . — . . � /. 45�o,�ess
<br /> ' 3�� �' seismic design requirements.
<br /> � ' �
<br /> ���,� �!: 21 9a9e . ;� . ...- . ., � r
<br /> � ? -�- ' So�aved • Ceiling areas of 1000 ft2 or less shall be exempt from later force _
<br /> This document has been revised based on current Buildin Code standards. In all buildin s,other than structures classified as a5°orless 45°orless brace 1 ATTACHMENT OPTIONS TO 5TRUCTURE (WOOD, CONCRETE OR STEEL) _
<br /> 9 9 W��e s b r a c i n g r e q u i r e m e n t s. _ A �
<br /> essential facilities, suspended ceilings installed in accordance with the prescriptive provisions of the 401 document are Lateral force bracin is the use of vertiCal Struts com ression
<br /> ' 9 � P STRUCTURE �
<br /> deemed to comply with the current building code interpretation. pOsts)and Splay wires (see figure 2). A. ATTACHMENT DEVICES TO STRUCTURE 1/4-INCH (6 mm) DIAMETER
<br /> This document provides the IBG2012 referenced standards for the installation of suspension systems for acoustical lay-in Crosstee Main beam X 3-INCH (75 mm) LONG CLOSED-EYE WOOD SCREWS; MINIMUM
<br /> ceilin s. Incor oration of this document will rovide a more uniform standard for installation and ins ection.This document is • �ateral Force Bracing shall be 12 feet on center(maximum)and PENETRATION 1 INCH (25 mm) INTO THE WOOD MEMBER. ' ,
<br /> g p p p begin no farther than 6 feet from walls.. TWO 12 GA. �
<br /> designed to accomplish the intent of the International Building Code(IBC)with regard to the requirements for seismic design figure 3 " 5PLAY WIRES
<br /> category D, E and F for suspended ceilings and related items. Unless supported by engineering,the suspension system shall be Maximum Recommended Lengths for • Seismic splay wires are to be four 12 gage wires attached to the 1 AT MAX. 8' � e B. NO. 12 GA. SPLAY WIRE LOOPED AROUND BOTTOM CHORD OF �
<br /> installed per these requirements and those of the referenced documents. Manufacturers'recommendations should be followed Vertical Struts main beam. Wires are arrayed 90°ffom each other and at an (2,5 mm) 9 � o OPEN JOINT OR TRUSS. O �
<br /> w here app lica b le. angle not exceeding 45°from the plane of the ceiling.:>��-� � � � ,
<br /> • � 2 �'� C. METAL 2-INCH x 2-INCH (50 mm x 50 mm) ANGLE, ATTACHED
<br /> i, ;
<br /> ��'� ��z�EMr conduit up to 5�to° . Seismic splay wires shall be attached to the grid and to the SUSPENDED �o TO CONCRETE OR STEEL WITH APPROVED FASTENERS. Z
<br /> � �i<�EMT conduit up to��s° structure in such a manner that they can support a design load of CEILING
<br /> not less than 200 pounds or the actual design load, with a safety D. TIE WIRE SPIKE MINIMUM 3/16-INCH (5 mm) DIAMETER x 2 .
<br /> ' �^EMT conduit up to 9�9° factor of 2, whichever is greater(figure 6b). , : INCHES (50 mm) LONG, DRILLED AND HAMMERED FOR CONCRETE.
<br /> � � � • Power Actuated Fasteners (PAF's), when used for seismic
<br /> � E. TIE WIRE WEDGE ANCHOR 1/4 INCH x 1-3/4 INCHES (6 mm x
<br /> 5 application as part of the prescriptive path in Seismic Design PARTITION 44 mm) , FOR CONCRETE. o
<br /> Single 1/a"metal stud(20 gage) up to 12�o�� Categories D, E and F, shall have an ICC-ES approval for seismic c�t �
<br /> Back-to-back 15/e°metal stud up to 15�0�� applications and shall require"special inspection" irrespective of N �-+
<br /> F. BEAM/FLANGE CLAMPS FOR STEEL STRUCTURE MEMBER. � N •�
<br /> (20 gage) the type of occupancy category the structure is in. PAF anchors +� � � � `
<br /> for kicker wires (splayed wires installed for purposes other than * � � 'n �
<br /> Single 2'/z'metal stud(20 gage) up to 13'6" , SPLAY WIRE TO BE WRAPPED AROUND ITSELF THREE FULL TURNS; �p @j
<br /> seismic restraint)are exempt from this requirement. _ E WITHIN A 3-INCH (75 mm) LENGTH. � a �''� k
<br /> Back-to-back 2'/:"metal stud{25 gage) up to 15'0" , _ cd Q i �
<br /> ��,�. ,;� :
<br /> b � �
<br /> l�,r�e:�=�: • Splay wires are to be within 2 inches of the connection of the N - cn �
<br /> Nore:Pren�,�- - � vertical strut to suspended ceiling. , = � ATTACHMENT OPTIONS AT PARTITION V � � m
<br /> calculations � W '� � �
<br /> General Recommendations • Rigid bracing may be used in lieu of splay wires. STRUCTURE I O I A. ATTACH PARTITION TRACK TO SUSPENDED CEILING MAIN RUNNER v� � O G
<br /> • Referenced sources er hierarch 2012 International Buildin Code IBC ,American Societ of Civil En ineers rigure aa � �
<br /> (A S C E 7-1 0),American Socie ty o f•Tes ting Ma teria ls (A S T M C 6 3 5,A S T M)C 6 3 6,A S T M E 5 8 0/E 5 8 0 M), an d A t t a c h e d W a l l M o�d i n g R e q u i r e m e n t s • C e i l i n g s w i t h p l e n u m s�e s s t h a n 1 2 i n c h e s t o s t ru c t u r e a r e n o t oNE RIGID BRACE , WITH Two No. 8 S-SCREWS. (DETAIL A ONLY) � '*� »
<br /> 3 b
<br /> AT MAX. 8 FEET N � y
<br /> Ceilings and InteriorSystems ConstructionAssociation (CISCA). required to have lateral force bracing. .; : � ,c e o'� B. 1/4-INCH (6 MM) CLOSED-EYE BOLT THROUGH PARTITION TRACK. � ''� � .a
<br /> / (2,500 mm) O.C. �,.o .,� � � p� o
<br /> • Partitions that are tied to the ceiling and all partitions greater than 6 feet in height shall be laterally braced to the y A mex;m�me•,Ze=mm, • Vertical struts must be positively attached to the suspension AT ALTERNATE - °� � g O
<br /> structure. Bracing shall be independent of the ceiling splay bracing system. systems and the structure above. , �:; r,�;� - ,s:�-<; SIDES OR SPLAY �� � � C. 2-INCH x 2-INCH (50 mm x 50 mm) METAL ANGLE WITH TWO
<br /> • For further information on bracing of non-load bearing partitions refer to NWCB Technical Document#200-501. 0 '�o O�` • The vertical strut may be EMT conduit, metal studs or a proprietary WIRES AS O ' ° v N0. 8 S-SCREWS IN PARTITION TRACK. Consultant .
<br /> • All main beams are to be Heavy Duty(HD). ,� compression post(see figure 3). 5HOWN IN DE
<br /> • Ceilings less than or equal to 144 ftz and surrounded by walls connected to the structure above are exempt from ,m 'A' • O * 5PLAY WIRE TO BE WRAPPED AROUND ITSELF THREE FULL TURNS;
<br /> the seismic design requirements. . z�s°^,^„ ``��4��` WBII MOICIIIIgS (figures 4a and 46) WITHIN A 3-INCH (75 mm) LENGTH.
<br /> • These recommendations are intended for suspended ceilings and related �0. • Wall moldings (perimeter closure angles)are required to have a
<br /> horizontaf flange 2 inches wide. One end of the ceiling grid shall 3O
<br /> components in areas that require resistance to the effects of earthquake motions. 3 SUSPENDED BRACING
<br /> f� �rP n� be attached to the wall molding, the other end shall have a /<inch CEILING
<br /> �`' " " g clearance from the wall and free to slide.
<br /> Unattached Wall Molding Requirements - - A. PLENUM HEIGHT TO 5 EEET (1 ,500 mm) : USE 3/4-INCH (19 mm)
<br /> • All wire ties are to be three tight turns around itself within three inches. Twelve gage •
<br /> maximums" ' 16 GA. (.0566 IN. ) COLD ROLLED CHANNEL OR 7/8-INCH (22 mm)
<br /> Hanger wire spaced 4 foot on center(figure 1). c�fimm> / • Where substantiatin documentation has been rovided to the
<br /> m••�m�mg-,=�=mm, g p PARTITION 25 GA. (.0188-INCH) FURRING CHANNEL OR 1-5/8 IN. (41 mm)
<br /> • Changes in ceiling planes will require positive bracing. �A�� local jurisdiction, perimeter clips may be used to satisfy the 25 GA. (.0188-INCH) STEEL STUD.
<br /> requirements for the 2-inch dosure angle : . ,
<br /> �""""`�. B. PLENUM HEIGHT 5-10 FEET (1,500 - 3 ,000 mm) : USE NESTED
<br /> � � `�0�o� ��e�s�����e
<br /> s��am�,u.��o
<br /> k�mppanmebr . The grid shall be attached at two adjacent walls (pop rivets or OR BACK TO BACK 3-1/2-INCH (90 mm) 25 GA. STEEL STUDS.
<br /> fiure 1 m�^�mu�^ °�°�s"�'� �
<br /> g aw��;e mm) sP,aaa��e anan
<br /> zm�s�m�� a���a"�=���wa��= .a approved method). Soffits extending to a point at least level
<br /> �A�E � oF a �'0�,4 with the bottom plane of the grid and independently supported C. ATTACH TO PARTITION WITH TWO N0. 8 S-SCREWS.
<br /> and laterally braced to the structure above are deemed to be
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<br /> . ���� HEADQUARTERS OREGON PAGE 2 OF 4
<br /> � ?Q`� � . ���'�� '� ` �' "�� � �' '� �"� �- '"� �� ACOUSTICAL CEILINGS ( ONNECTIONS FOR
<br /> � ' tel � ' . _ � � , , , PARTITION ATTACHMENT TO C
<br /> : . . . .
<br /> tel ' email email � nn 5/16" DRILL-IN EXPANSION ANCHOR NONBEARING PARTITIONS) (� �
<br /> IIIIMINIMUM OR APPROVED EA5TENER
<br /> -�-�L * THERE ARE TWO CONSIDERATIONS WHEN BRACING PARTITION5: •• �
<br /> �
<br /> STRUCTURAL 1 . THE INTERIOR NON-LOAD BEARING PARTITION SHALL BE BRACED TO Q Z H
<br /> CONCRETE MEET CHAPTER 16, SECTION 1607.13 OF THE UNIFORM BUILDING �
<br /> flgure 5a equivalent to walls. .�,�r:� �.� .. �, ,c �.� �,.-� ., _.�. <;� r�qure� • The layout and location of the seismic separation W � �
<br /> a�o+-6 METAL ANGL CODE (2 O 10) . ,
<br /> _. joint shall be per the designer of record and noted on � .
<br /> ��� � � � � WIDE X 2" LONG X 12 GA. MIN Z � 3 �
<br /> the plans. If a seismic separation joint is required by (50MM X 50MM X 12 GA. ) 2. ACOUSTICAL CEILINGS SHALL BE LATERALLY BRACED TO MEET UBC
<br /> Spreader Bars�rgure 4b� the designer, the designer may use the generic joint } STANDARD 25-2. w x pp
<br /> • Terminal ends of main runners and cross members shall be tied detailed in this document or a proprietary joint. The 3 TIGHT TURNS J � � �
<br /> together or have some other approved means to prevent their g � SPLAYED SEISMIC BRACING WIRE * THE INTENT OF THE CODE IS NOT TO USE LAY IN ACOUSTICAL CEILING w W �
<br /> �y�,�ma. amount of free movement
<br /> (gap desi n shall be a
<br /> spreading. Stabilizer bars, cross tees or other means to prevent , GRID AS AN ALTERNATE METHOD OF BRACING INTERIOR NON-LOAD � � a 3
<br /> spreading shall occur within 8 in. of each wa1L � - n'li u of seismic separation joints, the ceiling ma�'be BEARING WALLS, UNLES5 THE CEILING SYSTEM HAS BEEN DE5IGNED
<br /> _ _ — • Spreader bars are not required at perimeters where runners are m„ Um �P�P F�a�9e • y (ENGINEERED) TO SUPPORT THE PARTITION. � � � �
<br /> �''�,� R�°e� divided into areas less than 2500 square feet by the use '
<br /> attached directly to closure angles. (� � W �
<br /> Spreader bars are not required if a 90 degree intersecting cross or main • Terminals or services weighing 20 Ibs. but not more of partitions or soffits as follows: partitions shall extend a T1 * IT IS ACCEPTED INDUSTRY PRACTICE TO ATTACH THE PARTITION TRACK
<br /> minimum of 6 inches above the level of the lane of the L TO THE ACOUSTICAL GRID SYSTEM TEMPORARILY FOR ALIGNMENT UNTIL � � W
<br /> fi9u�e 5b•Countersloping . is within 8 inches of the erimeter wall. than 56 Ibs. shall have, in addition to 5.4.1, two 12 gage p H �l
<br /> p PERMANENT BRACING IS INSTALLED. THE ATTACHMENT OF STUD TRACK W a
<br /> wires connecting them to the ceiling system hangers or grid and shall be independently braced to the structure W
<br /> • Where substantiating documentation has been provided to the local TO THE ACOUSTICAL GRID DOES NOT VIOLATE THE INTENT OF THE CODE, x `
<br /> the structure above. These wires may be slack. above.Soffits shall extend to a point at least level with • ✓
<br /> ;���mm, jurisdiction, perimeter clips may be used to satisfy the requirements for � STRUCTURAL PROVIDED THAT THE PERMANENT BRACING OPTIONS FOR THE NONBEARING H E-� W
<br /> spreader bars. ` ' the bottom plane of the grid and shall be independently STRUCTURAL STEEL PARTITIONS ARE INSTALLED (REFERENCE ICBO ES REPORT 4071 Z �'1� � .
<br /> S�mq;o :Sa�9e • Terminals or services weighing more than 56 Ibs. shall supported and laterally braced to the structure above. CONCRETE SEISMIC CONNECTION DETAILS FOR GYPSUM NONBEARING PARTITIONS Q; r� � �
<br /> Hanger (Suspension) Wires�r;gu�es 5a ana sb� be supported directly from the structure above by < AND SUSPENDED CEILINGS) . Z, A N
<br /> approved hangers. (� O
<br /> • Hanger and perimeter wires must be plumb within 1 in 6 unless(flgure 5a) METAL ANGLE �� �
<br /> counter sloping wires are provided(figure 5b). : : : Spritlklet'S E"�
<br /> ' Seismic Separation Joints �r,gure�� c�
<br /> • Hanger wires shall be 12 gage and spaced 4 feet on center or 10 gage • For ceilings without rigid bracing, sprinkler head NOTE: *"�
<br /> s aced 5 feet on center. For ceiling areas exceeding 2,500 square feet, a
<br /> p � • seismic separation joint or full height wall partition that Penetrations shal) have a 2 inch oversize ring,sleeve or � * A NON-LOAD BEARING PARTITION (GYPSUM BOARD OR PLASTER) THAT
<br /> figure 6a • Any connection device at the supporting construction shall be capable adapter through the ceiling tile to allow free movement of 12 GA. SPLAYED SEI SMIC BRACING WIRE ENDS AT OR JUST ABOVE A SUSPENDED LAY-IN-TILE CEILING SYSTEM �
<br /> breaks the ceiling shall be provided unless analyses
<br /> of carrying not less than 100 pounds. ;,, > � are performed of the ceilings bracing system, closure at least 1 inch in all horizontal directions. Flexible head REQUIRES LATERAL SUPPORT BY MEANS DIRECTLY TO THE STRUCTURE.
<br /> Vertical hanger wire attachment
<br /> • Powder Actuated Fasteners(PAFs)are an approved method of angles and penetrations to provide sufficient clearance. design that can accommodate 1 inch free movement shall
<br /> ;i 3�4° attachment for hanger wires. ,- � , �: �:; be permitted as an alternate. EXCEPTION:
<br /> Shot-in anchor __.. . . __ . .. ,•rro � ,.",.: -_, .,..
<br /> ,. .., ,: .�q� ,. � ,����.�_>
<br /> s`��°t°`a'°°"�`e`e Terminal ends of each main beam and cross tee must be supported IF THE PARTITION GOES ALL THE WAY UP AND IS ATTACHED DIRECTLY �
<br /> � L+ TO THE STRUCTURE.
<br /> s,e•� r� * IF END OF PARTITION IS WITH IN 8 FEET (2,500 mm) OF AN ` .
<br /> ce'''"9°';P - --�--�- max. within 8 inches of each wall with a perimeter wire (see figure 4 & 5 a).
<br /> Glossary for this Document (regional terminology may vary) INTERSECTING PARTITION.
<br /> 3`�`r'S— - • Wires shall not attach to or bend around interfering material or
<br /> „ert;�,,,a„9e,W;�e -_ _ .__-__ equipment.A trapeze or equivalent device shall be used where CROSS TEES The cross member tnat interlock with the main perimeter ends of an accoustical ceiling grid. * A PARTITION SY5TEM MAY BE ATTACHED DIRECTLY TO THE SUPPORT DESCRIPTIO DATE
<br /> WOOD JOIST
<br /> obstructions preclude direct suspension.Trapeze suspensions shall beams, also known as cross runners or cross T-bars. AND/OR FRAMING MEMBER OF A SUSPENDED GYPSUM BOARD OR
<br /> PERiMETER CLIPS Proprietary angle bracket attached directly PERMIT 5ET 09/24/19
<br /> be sized to resist the dead load and lateral forces appropriate for the PLASTER SYSTEM, 12 INCHES (300 mm) 0.C. WITHOUT THE LATERAL
<br /> figure sb seismic category. DiFFUSER A circular or rectangular metal grill used for the to the wall molding/closure angle which allows for 3/4"move- n BRACING.
<br /> passage of air from a ducted system. ment in the event of seismic activity and interlocks properly I I
<br /> Splayed seismic bracing wire attachment Electrieal fixtures E55ENTIA�SERVICE BUI�DINGs Any buildings designed to be `^'ith ends of grid system. PARTITION TO RESIST 5 LBS/P.S.F. TRANSVERSE LOAD �
<br /> ,
<br /> drill-in expansion anchor-����� 1��. • used by public agencies as a fire station, police station,emer- PERIMETER wIREs Hanger wires placed within eight inches of
<br /> ,,,, • Light fixtures weighing less than 10 pounds shall have one 12 gage gency operations center, State Patrol office, sheriff's office, or the surrounding walls. ---- 3" X 14" DIAMETER * MAXIMUM PARTITION WEIGHT 15 LBS/P.S.F.
<br /> ' hanger wire connected from the fixture to the structure above. This wire
<br /> scN�c��ai�o�c�ece- 45` emergency commurncation dispatch center. . (75 mm x 6 mm)
<br /> ma be slaCk. < < P�ENUM The space above a suspended ceiling.
<br /> stee�strapt•widexz"�on9x y . CLOSED EYE SCREW WITH • IT IS ACCEPTED PRACTICE TO ATTACH THE PARTITION TRACK TO THE
<br /> �z 9a9e m'"""""' • Li ht fixtures wei hin more than 10 ounds and less than 56 Ibs.shal) GRID The main beams and cross tees of the suspension system. S�ACK wIRE A 12 a e wire that is not ti ht or taut. 1 IN. MIN. PENETRATI ON
<br /> 9 9 9 P 9 9 9 ACOUSTICAL GRID SYSTEM TEMPORARILY FOR ALIGNMENT UNTIL
<br /> 3���^5- -- - -- have two 12 gage wires attached at opposing comers of the light flxture to WaNGER Wi►2E 10 or 12 gage soft annealed wire used as pri- INTO WOOD. PERMANENT BRACING I5 INSTALLED.
<br /> sPiayed Se'Sm"b`a""9""`8" the structure 8bove.These wires may be slaCk. .. . - mary support for the grid system.Also called suspension wires. SPREADER or SPaGER BAR A bar with notches to prevent the •
<br /> suspension system from separating, also called a stabilizer
<br /> • Light Fixtures weighing more than 56 Ibs. shall be supported directly I.ATERaL FoftCE BRACtNG The bracing method used to prevent bar.
<br /> from the structure above by approved hangers. � - < < - , , < : : ceiling uplift or restrict lateral movement during a seismic event. sP�aY wiRES Wires installed at an angle rather than perpen-
<br /> .
<br /> Pendant mounted fixtures shall be directly supported from the structure Lateral force bracing consists of vertical struts and splay wires. dicular to the grid. 12 GA. SPLAYED WIRE
<br /> above using a 9 gage wire or an approved alternate support without MAIN BEAM The primary suspension member supported by
<br /> han er wires, also known as the main runner, car in tee, vER�ICA�STRUTs The rigid vertical member used in later- FILE ��:
<br /> using the ceiling suspension system for direct support. :,>,,r�� �T�e L,:L::- 9 ry g al force bracing of the suspension system.Also known as
<br /> carrying runner or mains. compression posts, seismic pods, seismic struts. Common JOB: 2 018-2 9
<br /> • Tandem fixturOS may utiliz2 COmmOn WirBS. MOLDING/CLOSURE ANGLE A light gauge metal angle or chan- materials are electrical conduit(EMT), metal studs or propri- '
<br /> nel fastened to the perimeter wall or partition to support the etary products. DWN: AB CHK: --
<br /> MechanicalServices � INTERIOR NON - LOAD BEARING PARTITION BRACING DETAILS
<br /> • Terminals or services weighing less than 20 Ibs.shall be positively attaehed The NWCB has been serving the construction industry for over forty years.It is recognized as a technical authority,educational body and spokesperson tor the wall and ceiling .
<br /> to the ceiling suspension main runners or to cross runners that have the industry.It provides services to architects and the construction community on all matters relating to the diversified wall and ceiling industry.As the industry's development A 1 . 6 S CALE• N.T. S .
<br /> and coordination organization,the NWCB saw the need to establish a document to provide clarification and the intent of NEHRP(National Earthquake Hazards Reduction �
<br /> S2t11@ CBfI")/Iflg C8p8Clty 8S tF12 tl'lalCl�Uflfl@I'S. :::. -. Program)an agency of FEMA(Federal Emergency Management Agency).It is meant to serve as a set of recommendations and is not intended for any specfic construction .
<br /> project.This technical document is to serve as a guideline and it is not intended for any specific construction projects.NWCB makes no express or implied warranty or �
<br /> PAGE 3 OF 4 guarantee of the techniques,construction methods or materials identified herein. PAGE 4 OF 4
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