Presentation on theme: "IBC Seismic Code Standards and Installation Requirements"— Presentation transcript:
1IBC Seismic Code Standards and Installation Requirements 1
2Today’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.
3Today’s Seismic Standards How Big Is The Risk?Currently 45 states use the International Building Code66% of the U.S. is now at some level of risk25 – 40% chance for a major quake in the Midwest
4Today’s Seismic Standards This is a complicated issue !Three variables determine a Seismic Design CategoryInterpretation of installation practices by code officials and architectsIntegration of seismic information into plans and specifications
5Today’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 motiontype of soil in a specific geographic areaseismic [building] use group designationIn 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
6Determine Maximum Ground Motion Seismic Design Category – Variable 1Determine Maximum Ground MotionGround acceleration is evaluated by location on hazards mapsTwo maps are used to list ground motion at 0.2 and 1 second periodsGround motion is presented as a percentage of the acceleration of gravity
7Determine [Soil] Site Class Seismic Design Category – Variable 2Determine [Soil] Site ClassSoil 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 typesSite Class D is used when specific data is not available unless class E or F soil types are likelyInvestigation 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.
8Determine Seismic Use Group Seismic Design Category – Variable 3Determine Seismic Use GroupA 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 groupSeismic Use Group II – high occupancy Examples: schools, large office buildings and utilitiesSeismic Use Group III – essential use Examples: police and fire stations; medical facilitiesThe 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.
9Non-Structural Systems Get A Closer Look Today’s Seismic StandardsNon-Structural Systems Get A Closer LookBefore IBC: Suspended ceilings could fail and render a space unusableAfter IBC: Suspended ceilings – designed and installed to meet IBC Seismic Design Categories – can survive intact
10IBC Installation Requirements for Suspended Ceilings Today’s Seismic StandardsIBC Installation Requirements for Suspended CeilingsProvide a suspension system strong enough to resist lateral forces imposed upon it without failingPrevent border panels from falling from the ceiling planePerimeter Wires – Categories D, E, and F
11“Old” and “New” Code Comparison: Seismic Design Category A and B Seismic Code Compliance“Old” and “New” Code Comparison: Seismic Design Category A and BIBC CategoryCISCA ZoneInstallation RequirementA, B0-1Ceiling installations should conform to basic minimums established in ASTM C 636.The IBC does not require any special ceilinginstallation considerations in these categories
12“Old” and “New” Code Comparison: Seismic Design Category C Seismic Code Compliance“Old” and “New” Code Comparison: Seismic Design Category CIBC CategoryCISCA ZoneInstallation RequirementC2To be installed to CISCA recommendations for areas subject to light-to-moderate seismic activity:Minimum 7/8” wall moldingGrid must not be attached to the wall molding3/8” clearance on all sides3/8” overlap of the grid on the wall moldingEnds of main beams and cross tees must be tied together to prevent their spreadingNo perimeter wiresThe 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.
13“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 FIBC CategoryCISCA ZoneInstallation RequirementD, E, F3-4To 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 moldingGrid must be attached to two adjacent walls – opposite walls must have a ¾” clearanceEnds of main beams and cross tees must be tied together to prevent their spreadingPerimeter support wiresHeavy-duty grid systemCeiling areas over 1,000 SF must have horizontal restraint wire or rigid bracingCeiling areas over 2,500 SF must have seismic separation joints or full height partitionsCeilings without rigid bracing must have 2” oversized trim rings for sprinklers and other partitionsChanges in ceiling plane must have positive bracingCable trays and electrical conduits must be independently supported and bracedSuspended ceilings will be subject to special inspectionThis practice creates a restrained ceiling.
14Armstrong has conducted 70 full scale seismic tests. Alternative Designs and MethodsCode officials may approve other installation designs based upon the following:IBC Section 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 Tests. Whenever code compliance is questionable … the building official can require tests as evidence of compliance.Armstrong has conducted 70 full scale seismic tests.
15IBC Seismic Design Category D, E, F Alternative Installation Test: Alternative Designs and MethodsIBC Seismic Design Category D, E, F Alternative Installation Test:Tested Prelude XL with heavy-duty main beams  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  instead of 2” wall moldingUsed 2” BERC clips [BERC2] and eliminated the need for stabilizer barsThis test verified that the system meets code performance requirements.The result: a more efficient installation – labor saving benefits.
16Total savings with BERC2: 30%, or $ .116/LF. BERC2 Cost SavingsThe 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.
17IBC Seismic Design Category C Alternative Installation Test: Alternative Designs and MethodsIBC Seismic Design Category C Alternative Installation Test:Tested Prelude XL intermediate-duty main beams  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.
18Total savings with BERC Solution: $ .103/LF. BERC Cost SavingsThe 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 = $ .074This comparison is based on a Prelude 2’ x 2’ installation. Cost reflects April 1, 2004 pricing.Total savings with BERC Solution: $ .103/LF.
19Armstrong BERC2 Solution BERC2 Cost SavingsTwo Approaches to IBC Categories D, E, FIBC RequirementsArmstrong BERC2 SolutionSolution Benefits2” molding7/8” moldingNarrow, sleek aesthetic with standard 7/8” wall moldingAttached 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 moldingEliminates installation and aesthetic problems associates with 2” wall molding¾” clearance at perimeter on unattached endsBERC2 clip with ¾” clearance on unattached endsBERC2 eliminates visiblepop rivets through the wall angleStabilizer bars to prevent the spread of main beams and cross teesBERC2 clip on all four wallsEliminates time and expense to install pop rivetsEliminates stabilizer barsLower cost solutionBetter access to the plenumHeavy-duty gridLateral bracingPerimeter support wireMeets code requirementNew 2” BERC clip
20Shake Table Test - Infusions Additional Armstrong TestingWe’ve also tested “specialty” and “floating” systems!Performed extensive testing on standard, specialty and floating ceiling solutionsTesting was performed at the State University of New York at Buffalo – Armstrong a premier Multidisciplinary Center for Earthquake Engineering Research [MCEER] partnerShake Table Test - InfusionsArchitects 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]!
21New Seismic Sales AidsCS-3543 “Seismic Installations: What You Need to Know”Key brochure messages:Rationale for the development of the new IBC codeReference to sections of the code that allow “alternative methods”Side-by-side comparison between IBC requirements and BERC2 solution
22New Seismic Sales Aids CS-3559 “Seismic Ceiling Installations” Key brochure messages:Don’t compromise your design intent [architect] with the use of 2” wall moldingArmstrong has demonstrated seismic performance with extensive testing on many systemsWe provide specs, drawings, and continued education on the web
23Other Seismic Support Tools For More Seismic Information on the Web:Latest product and solution newsSeismic Test SummariesSeismic Design Solution CAD renderingsSeismic FAQsIBC Guide Specification
24Seismic 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.
25What About Specifications? Seismic Information in Construction DocumentsHere’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 achieveSDC is to be listed in the construction documentsWhile 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
26Additional 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.