1. anticipated ground motion 2. type of soil in a specific geographic area 3. seismic use group designation

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1 CEILING SYSTEMS

2 Purpose of Installation Requirements for Suspended Ceilings Provide a suspension system strong enough to resist lateral forces imposed upon it without failing Prevent border panels from falling from the ceiling plane Federal Emergency Management Agency (FEMA) Seismic performance during recent large California earthquakes prompted FEMA to address several concerns including suspended ceiling performance during a seismic event. Research and tests demonstrated that current industry seismic standards (UC Standard 25-2) were not adequate. To support individual panels around the perimeter, FEMA determined that the key to good seismic performance is a wider wall molding on all sides. This led to the International uilding Code requirement for 2" wall molding on all sides. Source: FEMA 302 NEHRP Recommended Provisions for Seismic Regulations for New uildings and Other Structures Adoption of the International uilding Code Currently 44 States Use the International uilding Code 31 states are effective statewide 12 states have adopted by local government 3 states have adopted, but are not yet effective statewide Source: (December 29, 2003) New Seismic Categories According to the International uilding Code, a Seismic Design Category must be established for each construction project based on: 1. anticipated ground motion 2. type of soil in a specific geographic area 3. seismic use group designation Ask us about our new CES course on current seismic code requirements for commercial ceiling systems. Ask your Armstrong rep or call 877-ARMSTRONG for more information. 1

3 IC Category CISCA Zone Installation Requirement A, 0-1 Ceiling installation should conform to basic minimums established in ASTM C 636. C 2 To be installed to CISCA recommendations for areas subject to light to moderate seismic activity. Minimum 7/8" wall molding Grid must not be attached to the wall molding 3/8" clearance on all sides 3/8" overlap of the grid on the wall molding Ends of main beams and cross tees must be tied together to prevent their spreading No perimeter wires Additional Resources on Seismic Codes and Requirements TechLine at ARMSTRONG ( ) armstrong.com/seismic Visit these code related web sites: ASTM: SSC: FEMA: ICC: USGS: geohazards.cr.usgs.gov D, E, F 3-4 Installation must conform to CISCA recommendations for areas subject to severe seismic activity. IC categories D, E and F must also meet these additional requirements: Minimum 2" wall molding Grid must be attached to two adjacent walls opposite walls must have a 3/4" clearance Ends of main beams and cross tees must be tied together to prevent their spreading Perimeter support wires Heavy-duty grid system Ceiling areas over 1,000 SF must have horizontal restraint wire or rigid bracing Ceiling areas over 2,500 SF must have seismic separation joints or full height partitions Ceilings without rigid bracing must have 2" oversized trim rings for sprinklers and other penetrations Changes in ceiling plane must have positive bracing Cable trays and electrical conduits must be independently supported and braced Suspended ceilings will be subject to special inspection NOTE: Consult your local code professional for information specific to your region. 2

4 Code officials may approve other installation designs based upon the following: Section Alternative materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. Armstrong Testing as Evidence of Compliance Section Tests. Whenever there is insufficient evidence of compliance with the provisions of this code, or evidence that a material or method does not conform to the requirements of this code, or in order to substantiate claims for alternative materials or methods, the building official shall have the authority to require tests as evidence of compliance to be made at no expense to the jurisdiction. Armstrong conducted the following full scale seismic tests at the University at uffalo: IC category D, E, F Alternative Installation Test The PRELUDE L suspension system consisted of heavy-duty main beams (7301) and cross tees (L7348 and L7328). The system was installed according to CISCA Guidelines for Seismic Restraint, Direct Hung Suspended Ceiling Assemblies, and the International uilding Code with the following exceptions: 7/8" wall molding (7800) instead of 2" wall molding 2" ERC clips (ERC2) were used and eliminated the need for stabilizer bars This test demonstrated that the system performs to a level that is consistent with the requirements of the 2000 International uilding Code for Seismic Design Category D, E, F. Consult your local code professional for an actual compliance determination. 3

5 IC category C Alternative Installation Test This test consisted of PRELUDE L intermediate-duty main beams (7300) and cross tees (L7342 and L7328) and 7/8" wall molding (7800). The system was installed according to the International uilding Code Category C with the following exceptions: ERC clips were used and eliminated the need for stabilizer bars Grid was installed tight to two adjacent walls and less than 1/4" clearance on the other two walls This test demonstrated that the system performs to a level that is consistent with the requirements of the 2000 International uilding Code for Seismic Design Category C. Consult your local code professional for an actual compliance determination. For full test details, go to or call TechLine at 877 ARMSTRONG University at uffalo Research Facility The University at uffalo s Structural Earthquake Engineering Systems Laboratory (SEESL), is the flagship laboratory in the Multidisciplinary Center for Earthquake Engineering Research (MCEER). SEESL has a five-degree of freedom shake table, which means it can move in five different directions (horizontal, vertical, pitch, roll and yawl). The Multidisciplinary Center for Earthquake Engineering Research (MCEER) is a national center of excellence that develops and applies knowledge and advanced technologies to reduce earthquake losses. MCEER is principally sponsored by the National Science Foundation. The Center receives additional support from the Federal Emergency Management Agency (FEMA). 4

6 IC Category D, E, F Requirements Attached Wall 8" Max. LF 2" Hanger Wire Lateral Force racing Perimeter Wires Attached Wall Stabilizer ars LF 8" Max. 3/4" 2' o.c. 2" Unattached Wall To download CAD drawing details go to IC Requirements 2" molding Attached grid on two adjacent walls Pop rivets are acceptable 3/4" clearance at perimeter on unattached ends Stabilizer bars to prevent the spread of mains beams and cross tees 5 Heavy-duty grid Lateral bracing Perimeter support wire

7 Attached Wall Alternative Installation Using ERC2 8" Max. 7/8" Attached Wall To download CAD drawing details go to LF Hanger Wire ERC2 Clip Lateral Force racing Perimeter Wires LF 8" Max. 2' o.c. 7/8" 1/2" Unattached Wall Armstrong ERC2 Solution 7/8" molding Attached grid on two adjacent walls with the ERC2 NOTE: Attaching the ERC2 clip to the wall secures the grid and eliminates the need for pop rivets through the visible part of the wall molding ERC2 clip with 1/2 to 5/8" clearance on unattached ends ERC2 clip on all four walls Heavy-duty grid Lateral bracing Perimeter support wire Solution enefits Narrow, sleek aesthetic with standard 7/8" wall molding Eliminates installation and aesthetic problems associated with 2" wall molding ERC2 eliminates visible pop NEW 2" ERC CLIP rivets through the wall angle Eliminates time and expense to install pop rivets Eliminates stabilizer bars Lower cost solution etter access to the plenum Meets code requirement 6

8 IC Category C Requirements Stabilizer ars Hanger Wire 7/8" (all four sides) To download CAD drawing details go to 2' o.c. IC Requirements 7/8" molding 3/8" clearance on all sides 3/8" overlap of the grid on the wall molding Prevent the spread of mains/cross tees with stabilizer bars Perimeter wires are not needed Intermediate-duty grid NOTE: Requirements for essential use facilities may be different. Contact TechLine for details. 7

9 Tight Wall Alternative Installation Using ERC 7/8 Tight Wall Tight Wall To download CAD drawing details go to Hanger Wire ERC Clip 2' o.c. 7/8 1/4" Clearance Wall 1/4" Clearance Wall Armstrong ERC Solution 7/8" molding Grid can be tight on two adjoining walls and less than 1/4" clearance on other two walls ERC Clip on all cut cross tees Perimeter wires are not needed Intermediate-duty grid Solution enefits Meets code requirement Easy to square up the system Faster, tighter grid installation etter overall visual Eliminates stabilizer bars Lower cost solution etter access to the plenum Meets code requirements 8

10 The Case for Perimeter Wires In full scale seismic test evaluations, the common cause of system failure came from damage to cross tee end connectors (Armstrong and competitive systems). Damage occurs in one of two ways: Connector clip bends ase metal bends Damage at cross tee connections allow ceiling movement. When this damage occurs, it allows unbraced sections of ceiling to move up to 3/8" at each connection. The cumulative effect of damage at the cross tee connections may move the ceiling more than 2". Consider the following example: 2" Wall Molding 2" Wall Molding Unsupported cross tees allow panels to drop out. A 3/4" efore A C D E 3/4" 3/8" 3/8" 3/8" 3/8" After raced A C D E 4' o.c. Potential Movement A C D E 3/4" + 3/8" + 3/8" + 3/8" + 3/8" = 2-1/4" Without perimeter support wires, test results demonstrate that the load of the ceiling may cause the main beams and cross tees to move beyond the 2" wall molding and drop out. System failure at the perimeter does not conform to the requirements of the code. 9

11 For More Information CEILING SYSTEMS ARMSTRONG ( ) Customer Service Representatives 7:30 a.m. to 5:00 p.m. EST, Monday through Friday TechLine Technical information 8 a.m. to 5:30 p.m. EST, Monday through Friday FA or techline@armstrong.com Request a personal copy of the Armstrong Ceiling Systems catalog Latest product and solution news Seismic Test Summaries Submittal page Specification writing tool Literature and samples information Seismic Design Solution CAD renderings CS AWI Licensing Co. Printed in the United States of America