Laserfiche WebLink
(igwe 2 <br />Laterallorce Bracing <br />u• �. i�ss . <br />� <br />li9i�re 3 <br />Maximum Recommended Lengths 1or <br />Vertical Struts <br />z ea9e <br />n�rvea <br />omcc <br />NiICS <br />Smveu Pa11,n�! Bultl.iq� �epanmurit <br />Nofo: P/ewm arcoc grealn lnan 15'0' wJl rcpuhu engir:eonng <br />c:ncu;;iron,. <br />ligure 4a <br />Attached Wall Molding Requirements <br />�" SS:" <br />� <br />ligure 4b <br />Unaltached Wall Molding Requirements <br />,"w: <br />{. <br />Lateral Force Bracing Ir�9�re5 z a�d a� <br />• Ceilings conslrucled of lalh and plaster or gyosum board, screw or nail at- <br />Wched lo suspended members that support a ceiling on one level extending <br />from wall to wall shall be exempt trom the lateral force bracing requiremenls. <br />=_ocRo�. c�sca zo�re. a-� <br />• Lateral force bracing is the use ot vertical struts (compression posts) and <br />splay wires (see figure 2). <br />• For ceiling areas exceeding 1,000 square feet, horizontal restreint of the ceil- <br />irg to the structural system (lateral force bracing) shall be pmvideds�,�o�:: <br />ASCE i-05 section 10.5.622 e <br />• Lateral Force Bracing shall be 12 teel on center (maximum) and begin no <br />farther than 6 feet from walls. s�:���c�: ascn s���r����.�.o��� a-n <br />• Seismic splay wires are lo be tour 12 gage wires attached to the main beam. <br />Wires are arrayed 90° from eech other and al an angle not exceeding 45° from <br />the plane o( the ceiling. s�����u:: ascn se�:«,�c: ��,c•: a-n <br />• Seismic splay wires shall be attached to the grid and to the structure in such <br />a manner that they can support a design load of not less lhan 200 pounds or <br />the actual design Ioad, with a safety factor of 2, whichever is greater (figure <br />6b�. Snurce'.GISCFronr.s:f-3 <br />•"Powder-driven shot-in-anchors" (PAF's), when used tor seismic applicalion <br />as part of the prescriplive palh in Seismic Design Categories D, E and F, shall <br />have an ICC-ES approval for seismic applications and shall require "special <br />inspection" inespective of the type ot oceupancy category the structure is in. <br />PAF anchors for kicksr wires (splayed wires installed for purposes other than <br />seismic restrainQ are exempt trom lhis requiremenL 5ou�ce: siaie o� c�c�cw�, eu�m���3 <br />CaJas Oh�islon <br />• Spiay wires are to be within 2 inches of the connection of the vertical strut to <br />suspended ceiling. so�ro�: ascn se�,m�c :o���c a-a <br />• Rigid bracing may be used in lieu of splay wires. soo«o: nsce seo��oo ia.s.c.zz � <br />• Ceilings with plenums iess than 12 inches to strucWre are not required lo <br />have Iateral force hracing. so����o: ro�u,�d eo�ia���� 000�rtm��i <br />• Vertical struts must be positively attached to the suspension systems and the <br />struclure ahove. scu�ce: ciscti s-� <br />• The vertical strut may be EMT conduit, metal studs or a proprietary compres- <br />sion post (see tigure 3). <br />Wall Moldings �r9���s a� a�d .m) <br />• Wall moldings (perimeter closure angles) are required to have a ho�izontal <br />ilange 2 inches wide. One end o( the ceiling grid shall be attached to the wa�I <br />molding, the other end shall have a'/. inch clearance from the wall and tree to <br />S�IdB. Swrtc: ASCE 7-05 seetian 13a`.ti2.2 b <br />• Where substantialing documentation has been provided to the local jurisdic- <br />tion, perimeter clips may be used lo satisfy the requirements for the 2-inch <br />closure angle. so�,�,,, si,i� oi o�,�o�, ct��mn,p c�a,,:, o�����oo <br />• The grid shall be attached at two adjacent walls (pop rivats or aoproved meth- <br />od). Soffits extending to a point at least Ievei with lhe bottom plane of the grid <br />and independently supported and lalerally breced to the struc!ure above are <br />deemed to be equivalent to walls. so��.co: si;�;e or a��si�n, e�,aa��,y c�;des c��s�on <br />Spreader Bars I��e��o Qb) <br />• Spreader (spacer) bars shall be used to prevent the ends of the main beams <br />and cross lees at perimeter walls from spreading open during a seismic event. <br />Perimeter wires shall not be in lieu of spreader bars. s<:��,�": ciscn s��:;�n��,o��,5 <br />3-a <br />• Spreader 6ars are not required at perimeters where runners are atlached <br />directly to closure angles. <br />• Wire tying is an acceptable alternative lo spreader bars. <br />• Spreader bars are not required if a 90 degree intersecting cross or main is <br />within 8 inches of the perimeter wall. <br />• Where substantiating documentation has been provided to the local jurisdiction, <br />perimeler clips may be used to satisfy the requirements for spreader bars. <br />Sa�,�ice'. Smle ol Orer�an, &:tldir,�) Cotles Ovuun <br />� <br />NOFi1PJc3i 1PAC_,S GEILIIlG 6UFc:.0 • SUS%EN310t! 51'STEAIS FOP AC0115TIGP� LAV-IPl G[Ill'!GS <br />