Clayton Municipal Code Ch. 15.10 Disaster Repair and Reconstruction

This chapter establishes standards and regulations for the expeditious repair and reconstruction of structures damaged as a result of an uncontrollable event for which a local emergency has been declared by the City Council.

The provisions of this chapter are applicable to all damaged buildings and structures of all occupancies regulated by the City of Clayton following each uncontrollable event when a local emergency has been declared by the City Council. When approved by the Building Official, the requirements of this chapter may be waived in favor of repair recommendations included in an engineering evaluation as deemed in Section 15.100.040.

For the purposes of this chapter, the following definitions apply:

A. "Architect" is an individual licensed by the State of California to practice architecture as defined in the State of California Business and Professions Code.

B. "Civil Engineer" is an individual registered by the State of California to practice civil engineering as defined in the State of California Business and Professions Code.

C. "Current code" shall mean the edition of the California Building Standards Code as adopted by the City of Clayton, including any amendments, in effect at the time of the declaration of a local emergency by the City Council.

D. "Dangerous" shall mean any building or structure or any individual member with any of the structural conditions or defects described below shall be deemed dangerous:

1. The stress in a member or portion thereof due to all factored dead and live loads is more than one and one-third the nominal strength allowed in the current code.

2. Any portion, member of the building or structure, or any appurtenance within the building damaged to the extent that could potentially fail, detached or dislodged, or to collapse under normal operational condition or loading and thereby cause health and safety hazard.

3. Any portion of a building, or any member, appurtenance, or ornamentation on the exterior thereof with insufficient strength or stability, or attachment to resist lateral loading equal to two-thirds of that specified in the current code for similar buildings or structure without exceeding the nominal strength permitted in the current code.

4. The building or any portion thereof, is likely to collapse partially or completely due to damages caused by an uncontrollable event, fire, earthquake, wind, or flood; or any other similar cause.

5. The exterior walls or other vertical structural members list, lean, or buckle to such an extent that a plumb line passing through the center of gravity does not fall inside the middle one-third of the base.

E. "Engineering evaluation and analysis" is an evaluation and analysis of a damaged building or structure, or suspected damaged building or structure, performed under the direction of a structural/civil engineer or architect retained by the owner of the building or structure. Engineering evaluations and analysis shall, at a minimum, contain recommendations for repair with an estimate of construction cost for those repairs.

F. "Essential Service Facility" shall mean those buildings or structures which have been designated by the City Council to house facilities which are necessary for the emergency operations subsequent to a disaster, or an essential service facility as defined in the current code as an essential building.

G. "Structural/Civil Engineer" is an individual registered by the State of California to practice civil engineering and who has experience in design of structures.

H. "Substantial Damage" shall mean, for the purpose of determining compliance with the flood provisions of this code, damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred.

I. "Substantial Improvement" shall mean, for the purpose of determining compliance with the flood provisions of this code, any repair, alteration, addition, or improvement of a building or structure whose cost equals or exceeds fifty percent (50%) of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not include either:

1. Any project for improvement of a building required to correct existing health, sanitary, or safety code violations identified by the code official and that is the minimum necessary to assure safe living conditions, or

2. Any alteration of a historic structure provided that the alteration would not preclude the structure's continued designation as a historic structure.

J. "Substantial Structural Damage" shall mean a condition where:

1. In any story, the vertical elements of the lateral-force-resisting system, have suffered damage such that the lateral load-carrying capacity of the structure in any direction has been reduced by more than twenty percent (20%) from its pre-damaged condition, or

2. The capacity of any vertical gravity load-carrying component, or any group of such components, that supports more than thirty percent (30%) of the total area of the structure's floor(s) and roof(s) has been reduced more than twenty percent (20%) from its pre-damaged condition, and the remaining capacity of such affected elements with respect to all dead and live loads is less than seventy-five percent (75%) of that required by the current code for new buildings of similar structure, purpose, and location.

K. "Work Area" shall mean that portion or portions of a building consisting of all reconfigured spaces as indicated on the construction documents. Work area excludes other portions of the building where incidental work entailed by the intended work must be performed and portions of the building where work not initially intended by the owner is specifically required by this code.

The following repair provisions, excerpted and amended from the below-specified sections of the 2006 Edition of the International Existing Building Code (IEBC), as published by the International Code Council, shall apply:

International Existing Building Code Section 401—General (Amended)

401.2 Work area. The work area as defined in Chapter 15 shall be identified on the construction documents.

401.3 Occupancy and use. When determining the appropriate application of the referenced sections of this code, the occupancy and use of a building shall be determined in accordance with the California Building Code.

401.4 Scope. Repairs shall comply with the requirements of this chapter. Repairs to historic buildings shall comply with this chapter.

401.5 Permitted materials. Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted provided no hazard to life, health or property is created.

401.6 Conformance. The work shall not make the building less conforming than it was before the repair was undertaken.

401.7 Flood hazard areas. In flood hazard areas, repairs that constitute substantial improvement shall require that the building comply with the California Building Code and ASCE 24 "Flood Resistant Design and Construction."

International Existing Building Code Section 403—Building Elements and Materials (Amended)

403.1 Hazardous materials. Hazardous materials that are no longer permitted, such as asbestos and lead-based paint, shall not be used.

403.2 Glazing in hazardous locations. Replacement glazing in hazardous locations shall comply with the safety glazing requirements of the California Building Code as applicable. (Exception: Glass block walls, louvered windows and jalousies repaired with like materials.)

International Existing Building Code Section 404—Fire Protection (Amended)

404.1 General. Repairs shall be done in a manner that maintains the integrity of fire protection provided by the element being repairs.

International Existing Building Code Section 405—Means of Egress (Amended)

405.1 General. Repairs shall be done in a manner that maintains the level of protection provided for means of egress.

International Existing Building Code Section 406—Accessibility (Amended)

406.1 General. Repairs shall be done in a manner that maintains the level of accessibility provided.

International Existing Building Code Section 407—Structural (Amended)

407.1 General. Repairs of structural elements shall comply with this section.

407.1.1 Seismic and Wind evaluation and design. Seismic evaluation and design of an existing building and its components shall be based on the following criteria.

407.1.1.1 Evaluation and design procedures. The seismic evaluation and design shall be based on the procedures specified in the California Building Code, Appendix A of the International Existing Building Code (GSREB), or ASCE 41. For Category III and IV buildings, the procedures specified in Chapters A1, A2, A3, and A4 of Appendix A (GSREB) shall not be permitted. The procedures contained in Appendix A of the International Existing Building Code shall be permitted to be used as specified in Section 407.1.1.3.

407.1.1.2 CBC level seismic forces. When seismic forces are required to meet the California Building Code level, they shall be one of the following:

1. 100 percent of the values in the California Building Code. The R factor used for analysis in accordance with Chapter 16 of the California Building Code shall be the R factor specified for structural systems classified as "Ordinary" in accordance with the International Building Code Table 1617.6.2 unless it can be demonstrated that the structural system satisfies the proportioning and detailing requirements for systems classified as "Intermediate" or "Special".

2. Those associated with the BSE-1 and BSE-2 Earthquake Hazard Levels defined in ASCE 41. Where ASCE 41 is used, the corresponding performance levels shall be those shown in Table 407.1.1.2.

Table 407.1.1.2 ASCE 41 Performance Levels a [7]

407.1.1.3 Reduced CBC level seismic forces. When seismic forces are permitted to meet reduced California Building Code levels, they shall be one of the following:

1. 75 percent of the forces prescribed in the California Building Code. The R factor used for analysis in accordance with Chapter 16 of the California Building Code shall be the R factor as specified in Section 407.1.1.2.

2. In accordance with the applicable chapters in Appendix A of the International Existing Building Code as specified in Items 2.1 through 2.5 below. Structures or portions of structures that comply with the requirements of the applicable chapter in Appendix A shall be deemed to comply with the requirements for reduced California Building Code force levels.

2.1

The seismic evaluation and design of unreinforced masonry bearing wall buildings in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A1.

2.2

Seismic evaluation and design of the wall anchorage system in reinforced concrete and reinforced masonry wall buildings with flexible diaphragms in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A2.

2.3

Seismic evaluation and design of cripple walls and sill plate anchorage in residential buildings of light-frame wood construction in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A3.

2.4

Seismic evaluation and design of soft, weak, or open-front wall conditions in multiunit residential buildings of wood construction in Occupancy Category I or II are permitted to be based on the procedures specified in Appendix Chapter A4.

2.5

Seismic evaluation and design of concrete buildings and concrete with masonry infill buildings in all Occupancy Categories are permitted to be based on the procedures specified in Appendix Chapter A5.

1. Those prescribed by ASCE 31 based on the applicable performance level as shown in Table 407.1.1.2.

2. Those associated with the BSE-1 Earthquake Hazard Level defined in ASCE 41 and the performance level as shown in Table 407.1.1.2.

407.2 Reduction of strength. Repairs shall not reduce the structural strength or stability of the building, structure, or any individual member thereof. (Exception: Such reduction shall be allowed provided the capacity is not reduced to below the California Building Code levels.)

407.3 Repairs to damaged buildings. Repairs to damaged buildings shall comply with this section.

407.3.1 Dangerous conditions. Regardless of the extent of structural damage, dangerous conditions shall be eliminated.

407.3.2 Substantial structural damage to vertical elements of the lateral-force-resisting system. A building that has sustained substantial structural damage to the vertical elements of its lateral force resisting system shall be evaluated and repaired in accordance with the applicable provisions of Section 407.3.2.1 through 407.3.2.3.

407.3.2.1 Evaluation. The building shall be evaluated by a registered design professional, and the evaluation findings shall be submitted to the building inspector. The evaluation shall establish whether the damaged building, if repaired to its pre-damage state, would comply with the provisions of the California Building Code. Wind forces for this evaluation shall be those prescribed in the California Building Code. Seismic forces for this evaluation are permitted to be the reduced level seismic forces specified in Code Section 407.1.1.3.

407.3.2.2 Extent of repair for compliant buildings. If the evaluation establishes compliance of the pre-damage building in accordance with Section 407.3.2.1, then repairs shall be permitted that restore the building to its pre-damage state, using materials and strengths that existed prior to the damage.

407.3.2.3 Extent of repair for non-compliant buildings. If the evaluation does not establish compliance of the pre-damage building in accordance with Section 407.3.2.1, then the building shall be rehabilitated to comply with applicable provisions of the California Building Code for load combinations including wind or seismic forces.

The wind design level for the repair shall be as required by the building code in effect at the time of original construction unless the damage was caused by wind, in which case the design level shall be as required by the code in effect at the time of original construction or as required by the California Building Code, whichever is greater.

Seismic forces for this rehabilitation design shall be those required for the design of the pre-damaged building, but not less than the reduced level seismic forces specified in Section 407.1.1.3. New structural members and connections required by this rehabilitation design shall comply with the detailing provisions of the California Building Code for new buildings of similar structure, purpose, and location.

407.3.3 Substantial structural damage to vertical load-carrying components. Vertical load-carrying components that have sustained substantial structural damage shall be rehabilitated to comply with the applicable provisions for dead and live loads in the California Building Code. Undamaged vertical load-carrying components that receive dead or live loads from rehabilitated components shall also be rehabilitated to carry the design loads of the rehabilitation design. New structural members and connections required by this rehabilitation design shall comply with the detailing provisions of the California Building Code for new buildings of similar structure, purpose, and location.

407.3.3.1 Lateral force-resisting elements. Regardless of the level of damage to vertical elements of the lateral force-resisting system, if substantial structural damage to vertical load-carrying components was caused primarily by wind or seismic effects, then the building shall be evaluated in accordance with Section 407.3.2.1 and, if noncompliant, rehabilitated in accordance with Section 407.3.2.3.

407.3.4 Less than substantial structural damage. For damage less than substantial structural damage, repairs shall be allowed that restore the building to its pre-damage state, using materials and strengths that existed prior to the damage. New structural members and connections used for this repair shall comply with the detailing provisions of the California Building Code for new buildings of similar structure, purpose, and location.

407.3.4 Flood hazard areas. In flood hazard areas, buildings that have sustained substantial damage shall be brought into compliance with Section 1612 of the California Building Code.

707.7 Voluntary lateral-force-resisting system alterations. Alterations of existing structural elements and additions of new structural elements that are initiated for the purpose of increasing the lateral-force-resisting strength or stiffness of an existing structure and that are not required by other sections of this code shall not be required to be designed for forces conforming to the California Building Code provided that an engineering analysis is submitted to show that:

1. The capacity of existing structural elements required to resist forces is not reduced;

2. Either the lateral loading to existing structural elements is not increased beyond their capacity, or the lateral loading to existing structural elements is not increased by more than 10%;

3. New structural elements are detailed and connected to the existing structural elements as required by the California Building Code;

4. New or relocated nonstructural elements are detailed and connected to existing or new structural elements as required by the California Building Code; and

5. A dangerous condition as defined in this code is not created.

Voluntary alterations to lateral-force-resisting systems conducted in accordance with Appendix A of the International Existing Building Code and the referenced standards of this code shall be permitted.

International Existing Building Code Section 408—Electrical (Amended)

408.1 Material. Existing electrical wiring and equipment undergoing repair shall be allowed to be repaired or replaced with like material.

International Existing Building Code Section 409—Mechanical (Amended)

409.1 General. Existing mechanical systems undergoing repair shall not make the building less conforming than it was before the repair was undertaken.

International Existing Building Code Section 410—Plumbing (Amended)

410.1 Materials. Plumbing materials and supplies shall not be used for repairs that are prohibited in the California Plumbing Code.

Footnotes:

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a. Performance Levels for Occupancy Category III shall be taken as halfway between the performance levels specified for Occupancy Category II and Occupancy Category IV.

All damaged chimneys shall be reconstructed to comply with the requirements of Chapter 31 of the current code. In addition, damaged portions of chimneys shall be removed or replaced in accordance with Appendix A. (Note: Appendix A is Los Angeles Regional Uniform Code Program Information Bulletin/Public Building Code P/BC 2002-70 Revised: 08-17-01, [Previously issued as SP-2].)

A. Buildings or structures which are included on a national, state or local register of historic places or which are qualifying structures within a recognized historic district, which have been damaged as a result of an uncontrollable event, shall have an engineering evaluation performed.

B. The minimum criteria for repair shall be as included in Section 15.100.040 Repair Criteria with due consideration given to the historical rating and nature of the structures. Additional standards and criteria, as noted in Part 8, Title 24, California Code of Regulations, the State of California Historic Building Code, shall apply.

C. Where conflicts exist between the standards contained herein and the State of California Historic Building Code, the Historic Building Code shall govern.

Any action taken pursuant to this chapter may be appealed to the City Council.

(Ord. 447, 2013)