CHAPTER 34 EXISTING STRUCTURES - ecodes.biz

1 CHAPTER 34 EXISTING STRUCTURESSECTION provisions of this CHAPTER shall control thealteration, repair,additionand change of occupancy of exist-ing :Existingbleachers, grandstands and foldingand telescopic seating shall comply with ICC adopted by the State of , repairs, additions andchanges of occupancy to EXISTING STRUCTURES shall comply withthe provisions for alterations, repairs, additions and changes ofoccupancy in theFire Code, Fuel Gas Code, Mechanical Code,Plumbing Code, Residential Codeand NFPA Building materials shall complywith the requirements of this EXISTING already in use in abuilding in compliance with requirements or approvals ineffect at the time of their erection or installation shall bepermitted to remain in use unless determined by the build-ing code official to be dangerous to life, health or such conditions are determined to be dangerous tolife, health or safety.

2 They shall be mitigated or made New and replacement as oth-erwise required or permitted by this code, materials permit-ted by the applicable code for new construction shall beused. Except for structural repairs and alterations, like mate-rials shall be permitted for repairs and alterations, providedno hazard to life, health or property is created. Hazardousmaterials shall not be used where the code for new construc-tion would notpermittheir use in buildings of similar occu-pancy, purpose and Alternative performed in accor-dance with the latest revision of oregon alternate method08-05 shall be deemed to comply with the provisions of following words and terms shall, forthe purposes of this CHAPTER and as used elsewhere in the code,have the meanings shown building or structure or portion thereofthat meets any of the conditions described below shall bedeemed dangerous:1.

3 The building or structure has collapsed, partially col-lapsed, moved off its foundation or lacks the support ofground necessary to support There exists a significant risk of collapse, detachmentor dislodgment of any portion, member, appurtenanceor ornamentation of the building or structure under ser-vice structure erected prior to thedate of adoption of the appropriate code, or one for which alegal buildingpermithas been CHAPTER 11, STRUCTURAL conditionwhere:1. In anystory, the vertical elements of the lateral force-resisting system have suffered damage such that the lat-eral load-carrying capacity of the structure in any hori-zontal direction has been reduced by more than 20percent from its pre-damage condition; or2. The capacity of any vertical gravity load-carrying com-ponent, or any group of such components, that supportsmore than 30 percent of the total area of the structure sfloor(s) and roof(s) has been reduced more than 20 per-cent from its pre-damage condition and the remainingcapacity of such affected elements, with respect to alldead and live loads, is less than 75 percent of thatrequired by this code for new buildings of similar struc-ture, purpose and CHAPTER 11, to any building or structure shallcomply with the requirements of this code for new construc-tion.

4 Alterations to the EXISTING building or structure shall bemade to ensure that the EXISTING building or structure togetherwith theadditionare no less conforming with the provisions ofthis code than the EXISTING building or structure was prior to theaddition. An EXISTING building together with its additions shallcomply with the height and area provisions of CHAPTER Flood hazard buildings and STRUCTURES inflood hazard areas established in Section , anyadditionthat constitutes substantial improvement of theexisting struc-ture, as defined in Section , shall comply with the flooddesign requirements for new construction, and all aspects oftheexisting structureshall be brought into compliance with therequirements for new construction for flood buildings and STRUCTURES in flood hazard areas establishedin Section , any additions that do not constitute substan-tial improvement or substantial damage of theexisting structure ,as defined in Section , are not required to comply with theflood design requirements for new OREGON STRUCTURAL SPECIALTY CODE611>1M.

5 \data\CODES\STATE CODES\Oregon\2010\Structural Specialty_Building\Final VP\ , January 08, 2010 12:43:18 PMColor profile: Generic CMYK printer profileComposite Default EXISTING structural elements carrying gravity EXISTING gravity load-carrying structural element forwhich anadditionand its related alterations cause an increasein design gravity load of more than 5 percent shall be strength-ened, supplemented, replaced or otherwise altered as needed tocarry the increased load required by this code for new struc-tures. Any EXISTING gravity load-carrying structural elementwhose gravity load-carrying capacity is decreased shall be con-sidered an altered element subject to the requirements of Sec-tion Any EXISTING element that will form part of thelateral load path for any part of theadditionshall be consideredan EXISTING lateral load-carrying structural element subject tothe requirements of Section Design live theadditiondoes notresult in increased design live load, EXISTING gravityload-carrying structural elements shall be permitted to beevaluated and designed for live loadsapprovedprior to theaddition.

6 If theapprovedlive load is less than that requiredby Section 1607, the area desined for the nonconforminglive load shall be posted with placards ofapproveddesignindicating theapprovedlive load. Where theadditiondoesresult in increased design live load, the live load required bySection 1607 shall be EXISTING structural elements carrying lateral theadditionis structurally independent of theexistingstructure, EXISTING lateral load-carrying structural elementsshall be permitted to remain unaltered. Where theadditionisnot structurally independent of theexisting structure , theexist-ing structureand itsadditionacting together as a single struc-ture shall be shown to meet the requirements of Sections 1609and :Any EXISTING lateral load-carrying structuralelement whose demand-capacity ratio with theadditionconsidered is no more than 10 percent greater than itsdemand-capacity ratio with theadditionignored shall bepermitted to remain unaltered.

7 For purposes of calculatingdemand-capacity ratios, the demand shall consider applica-ble load combinations with design lateral loads or forces inaccordance with Sections 1609 and 1613. For purposes ofthis exception, comparisons of demand-capacity ratios andcalculation of design lateral loads, forces and capacitiesshall account for the cumulative effects of additions andalterations since original requirements for alterationsshall be in accordance with this section. Where the existingseismic force-resisting system is a type that can be desig-nated ordinary, values ofR, 0andCdfor the EXISTING seis-mic force-resisting system shall be those specified by thiscode for an ordinary system unless it is demonstrated thatthe EXISTING system will provide performance equivalent tothat of a detailed intermediate or special as provided by Section or thissection, alterations to any building or structure shall complywith the requirements of the code for new construction.

8 Alter-ations shall be such that the EXISTING building or structure is noless complying with the provisions of this code than the exist-ing building or structure was prior to :1. An existingstairwayshall not be required to complywith the requirements of Section 1009 where theexisting space and construction does not allow areduction in pitch or Handrails otherwise required to comply with shall not be required to comply with therequirements of Section regarding full exten-sion of the handrails where such extensions would behazardous due to plan Flood hazard buildings and STRUCTURES inflood hazard areas established in Section , anyalter-ationthat constitutes substantial improvement of the existingstructure, as defined in Section , shall comply with theflood design requirements for new construction, and all aspectsof theexisting structureshall be brought into compliance withthe requirements for new construction for flood buildings and STRUCTURES in flood hazard areas estab-lished in Section , any alterations that do not constitutesubstantial improvement or substantial damage of the existingstructure, as defined in Section , are not required to com-ply with the flood design requirements for new EXISTING structural elements carrying gravity EXISTING gravity load-carrying structural element forwhich analterationcauses an increase in design gravity load ofmore than 5 percent shall be strengthened, supplemented,replaced or otherwise altered as needed to carry the increasedgravity load required by this code for new STRUCTURES .

9 Anyexisting gravity load-carrying structural element whose grav-ity load-carrying capacity is decreased as part of thealterationshall be shown to have the capacity to resist the applicabledesign gravity loads required by this code for new Design live thealterationdoes notresult in increased design live load, EXISTING gravityload-carrying structural elements shall be permitted to beevaluated and designed for live loadsapprovedprior to thealteration. If theapprovedlive load is less than that requiredby Section 1607, the area designed for the nonconforminglive load shall be posted with placards ofapproveddesignindicating theapprovedlive load. Where thealterationdoesresult in increased design live load, the live load required bySection 1607 shall be EXISTING structural elements carrying lateral as permitted by Section , where thealterationincreases design lateral loads in accordance with Section 1609or 1613, or where thealterationresults in a structural irregular-ity as defined in ASCE 7, or where thealterationdecreases thecapacity of any EXISTING lateral load-carrying structural ele-ment, the structure of the altered building or structure shall beshown to meet the requirements of Sections 1609 and.

10 Any EXISTING lateral load-carrying structuralelement whose demand-capacity ratio with thealterationconsidered is no more than 10 percent greater than itsdemand-capacity ratio with thealterationignored shall be6122010 OREGON STRUCTURAL SPECIALTY CODEEXISTING STRUCTURES2M:\data\CODES\STATE CODES\Oregon\2010\Structural Specialty_Building\Final VP\ , January 08, 2010 12:43:19 PMColor profile: Generic CMYK printer profileComposite Default screenpermitted to remain unaltered. For purposes of calculatingdemand-capacity ratios, the demand shall consider applica-ble load combinations with design lateral loads or forces perSections 1609 and 1613. For purposes of this exception,comparisons of demand-capacity ratios and calculation ofdesign lateral loads, forces, and capacities shall account forthe cumulative effects of additions and alterations sinceoriginal requirements for alterationsshall be in accordance with this section.