IBC Seismic Code Standards and Installation Requirements 1

Today’s Seismic Standards What Is The IBC? It is the first model building code to specifically address the differences in seismic hazard based on soil type. It can significantly impact the cost of installing suspended ceilings in areas that have not historically required seismic installations. This new code reflects an increase in the risk safety factors. Protecting for that larger event will improve the survivability of our building stock, but will increase the costs associated with installation of suspended ceilings in many areas of the country.

Today’s Seismic Standards How Big Is The Risk? Currently 45 states use the International Building Code 66% of the U.S. is now at some level of risk 25 – 40% chance for a major quake in the Midwest                                       

Today’s Seismic Standards This is a complicated issue ! Three variables determine a Seismic Design Category Interpretation of installation practices by code officials and architects Integration of seismic information into plans and specifications

Today’s Seismic Standards According to the International Building Code [IBC], a Seismic Design Category must be established for each construction project based on three variables: anticipated ground motion type of soil in a specific geographic area seismic [building] use group designation In the former CISCA zone classification, an entire geographical area determined construction methods. The IBC ‘project by project’ analysis is a major change! The design team is responsible for the analysis required to assign a Seismic Design Category to a project. 2

Determine Maximum Ground Motion Seismic Design Category – Variable 1 Determine Maximum Ground Motion Ground acceleration is evaluated by location on hazards maps Two maps are used to list ground motion at 0.2 and 1 second periods Ground motion is presented as a percentage of the acceleration of gravity

Determine [Soil] Site Class Seismic Design Category – Variable 2 Determine [Soil] Site Class Soil type is evaluated to a depth of 100' The “Site Class” is rated A through F, where A is hard rock, and F is more unstable soil types Site Class D is used when specific data is not available unless class E or F soil types are likely Investigation of the site is the second variable. Soil type can have a significant impact on the design and construction of projects, as it could introduce changes in requirements for similar projects built within a geographical area.   Naming of soil types caused some confusion, since the format is the same as the Seismic Design Category. The default soil type “D” provision also added confusion, leading to a declaration that “all sites in … are D.” Being soil type “D” will not automatically make the Seismic Design Category a “D.” Building officials can overrule the default to “D” if they feel that Type “E” or “F” soil is likely to be present.

Determine Seismic Use Group Seismic Design Category – Variable 3 Determine Seismic Use Group A risk factor is assigned based on the occupancy of the structure and how critical the operability of the facility is in the event of a disaster, such as an earthquake. Seismic Use Group I – normal occupancy Examples: everything not assigned to another group Seismic Use Group II – high occupancy Examples: schools, large office buildings and utilities Seismic Use Group III – essential use Examples: police and fire stations; medical facilities The third variable is the use of the building. This idea is not new. Building codes have long recognized that some uses are more important than others. Group I contains normal occupancy structures, Group II is high occupancy, and Group III is essential use facilities.   NOTE – Do not click on the hot text if you are pressed for time [AIA CES presentation]. Most architects should know what these groups are about.

Non-Structural Systems Get A Closer Look Today’s Seismic Standards Non-Structural Systems Get A Closer Look Before IBC: Suspended ceilings could fail and render a space unusable After IBC: Suspended ceilings – designed and installed to meet IBC Seismic Design Categories – can survive intact

IBC Installation Requirements for Suspended Ceilings Today’s Seismic Standards IBC 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 Perimeter Wires – Categories D, E, and F

“Old” and “New” Code Comparison: Seismic Design Category A and B Seismic Code Compliance “Old” and “New” Code Comparison: Seismic Design Category A and B IBC Category CISCA Zone Installation Requirement A, B 0-1 Ceiling installations should conform to basic minimums established in ASTM C 636. The IBC does not require any special ceiling installation considerations in these categories

“Old” and “New” Code Comparison: Seismic Design Category C Seismic Code Compliance “Old” and “New” Code Comparison: Seismic Design Category C IBC Category CISCA Zone Installation Requirement 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 The notion of a free-floating ceiling is new, and will impact the installed cost. Ceilings that cannot touch the walls are more expensive to install, because it is harder to keep them straight and square. The IBC installation requirements for Seismic Design Category [SDC] C exempts ceilings in most one and two story buildings unless they are Seismic Use Group III [essential facilities]. The objective of this standard is to create an unrestrained ceiling.

“Old” and “New” Code Comparison: Seismic Design Categories D, E, and F Seismic Code Compliance “Old” and “New” Code Comparison: Seismic Design Categories D, E, and F IBC Category CISCA Zone Installation Requirement D, E, F 3-4 To be installed to CISCA recommendations for areas subject to severe seismic activity. IBC 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 ¾” 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 partitions 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 This practice creates a restrained ceiling.

Armstrong has conducted 70 full scale seismic tests. Alternative Designs and Methods Code officials may approve other installation designs based upon the following: IBC Section 104.11 Alternative materials, design and methods of construction and equipment. The provisions are not intended to prevent the installation of any material … providing that alternatives are approved. IBC Section 101.11.1 Tests. Whenever code compliance is questionable … the building official can require tests as evidence of compliance. Armstrong has conducted 70 full scale seismic tests.

IBC Seismic Design Category D, E, F Alternative Installation Test: Alternative Designs and Methods IBC Seismic Design Category D, E, F Alternative Installation Test: Tested Prelude XL with heavy-duty main beams [7301] and cross tees [XL7348 and XL7328]. The system was installed according to CISCA guidelines for seismic restraint, and the IBC, with the following exceptions: Used 7/8” wall molding [7800] instead of 2” wall molding Used 2” BERC clips [BERC2] and eliminated the need for stabilizer bars This test verified that the system meets code performance requirements. The result: a more efficient installation – labor saving benefits.

Total savings with BERC2: 30%, or $ .116/LF. BERC2 Cost Savings The BERC2 eliminates the expense of stabilizer bars on the two unattached walls. The #7800 is substituted for the more expensive 2” molding. This comparison is based on a Prelude 2’ x 2’ installation. Cost reflects April 1, 2004 pricing. Total savings with BERC2: 30%, or $ .116/LF.

IBC Seismic Design Category C Alternative Installation Test: Alternative Designs and Methods IBC Seismic Design Category C Alternative Installation Test: Tested Prelude XL intermediate-duty main beams [7300] and cross tees [XL7342 and XL7328] and 7/8” wall molding. The system was installed according to the IBC Category C with the following exceptions: Used BERC clip to eliminate stabilizer bars. Installed grid tight to two adjacent walls - and less than ¼” clearance on the opposite walls. Verified that the system meets required code performance. The result: a ceiling that is easier to square at the perimeter.

Total savings with BERC Solution: $ .103/LF. BERC Cost Savings The BERC creates a tighter overall grid installation, more efficient squaring of grid, and easier plenum access at the perimeter. Savings calculation: BERC2 only placed at cut cross tees [3/4 of the perimeter] = $ .098 x ¾ = $ .074 This comparison is based on a Prelude 2’ x 2’ installation. Cost reflects April 1, 2004 pricing. Total savings with BERC Solution: $ .103/LF.

Armstrong BERC2 Solution BERC2 Cost Savings Two Approaches to IBC Categories D, E, F IBC Requirements Armstrong BERC2 Solution Solution Benefits 2” molding 7/8” molding Narrow, sleek aesthetic with standard 7/8” wall molding Attached grid on two adjacent walls [pop rivets are acceptable] Attached grid on two adjacent walls with the BERC2. NOTE: Attaching the BERC2 clip to the wall secures the grid and eliminates the need for pop rivets through the visible part of the wall molding Eliminates installation and aesthetic problems associates with 2” wall molding ¾” clearance at perimeter on unattached ends BERC2 clip with ¾” clearance on unattached ends BERC2 eliminates visible pop rivets through the wall angle Stabilizer bars to prevent the spread of main beams and cross tees BERC2 clip on all four walls Eliminates time and expense to install pop rivets Eliminates stabilizer bars Lower cost solution Better access to the plenum Heavy-duty grid Lateral bracing Perimeter support wire Meets code requirement New 2” BERC clip

Shake Table Test - Infusions Additional Armstrong Testing We’ve also tested “specialty” and “floating” systems! Performed extensive testing on standard, specialty and floating ceiling solutions Testing was performed at the State University of New York at Buffalo – Armstrong a premier Multidisciplinary Center for Earthquake Engineering Research [MCEER] partner Shake Table Test - Infusions Architects can specify and code officials approve non- standard ceilings confident that they have been tested to meet IBC requirements [Serpentina, Infusions, Axiom, WoodWorks and MetalWorks]!

New Seismic Sales Aids CS-3543 “Seismic Installations: What You Need to Know” Key brochure messages: Rationale for the development of the new IBC code Reference to sections of the code that allow “alternative methods” Side-by-side comparison between IBC requirements and BERC2 solution

New Seismic Sales Aids CS-3559 “Seismic Ceiling Installations” Key brochure messages: Don’t compromise your design intent [architect] with the use of 2” wall molding Armstrong has demonstrated seismic performance with extensive testing on many systems We provide specs, drawings, and continued education on the web

Other Seismic Support Tools For More Seismic Information on the Web: www.armstrong.com/seismic Latest product and solution news Seismic Test Summaries Seismic Design Solution CAD renderings Seismic FAQs IBC Guide Specification

Seismic National Advertising You’ll see ads in industry periodicals such as Walls & Ceilings and AWCI’s Construction Dimensions this Spring. Note reference to the web address specifically dedicated to Seismic information.

What About Specifications? Seismic Information in Construction Documents Here’s what you need to look for: A Seismic Design Category [SDC] tells the construction team what level of performance the building and its systems must achieve SDC is to be listed in the construction documents While exact location in the CDs might vary by jurisdiction, most likely it will be in the general conditions section of the specification, and in general notes on the first page of structural drawings

Additional Resources and References TechLine Can Provide Assistance! The 2004 catalog references Seismic performance [note the new icons]. Need guide specs, samples, or additional technical assistance? We can help you and your customers meet Seismic code requirements. Call TechLine for all your Seismic needs.