General scope, definitions, and roof drainage

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

• CBC § 1501.1 High relevance — show source text

  ICC code development note: Code change proposals to sections preceded by the designation [BF] or [P] will be considered by one of the code development committees meeting during the 2024 (Group A) Code Development Cycle. All other code change proposals will be considered by a code development committee meeting during the 2025 (Group B) Code Development Cycle.

  SECTION 1501—GENERAL

  1501.1 Scope. The provisions of this chapter shall govern the design, materials, construction and quality of roof assemblies, and rooftop structures.

  SECTION 1502—ROOF DRAINAGE

  [P] 1502.1 General. Design and installation of roof drainage systems shall comply with this section, Section 1611 of this code and Chapter 11 of the California Plumbing Code .

  [P] 1502.2 Secondary (emergency overflow) drains or scuppers. Where roof drains are required, secondary (emergency overflow) roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water will be entrapped if the primary drains allow buildup for any reason. The installation and sizing of secondary emergency overflow drains, leaders and conductors shall comply with Section 1611 of this code and Chapter 11 of the California Plumbing Code .

  1502.3 Gutters. Gutters and leaders placed on the outside of buildings, other than Group R-3, private garages and buildings of Type V construction, shall be of noncombustible material or not less than Schedule 40 plastic pipe.

  SECTION 1503—WEATHER PROTECTION

  1503.1 General. Roof decks shall be covered with approved roof coverings secured to the building or structure in accordance with the provisions of this chapter. Roof coverings shall be designed in accordance with this code, and installed in accordance with this code and the manufacturer’s approved instructions.

  1503.2 Flashing. Flashing shall be installed in such a manner so as to prevent water from entering the wall and roof through joints in copings, through moisture-permeable materials and at intersections with parapet walls and other penetrations through the roof plane.

  1503.2.1 Locations. Flashing shall be installed at wall and roof intersections, at gutters, wherever there is a change in roof slope or direction and around roof openings. Where flashing is of metal, the metal shall be corrosion resistant with a thickness of not less than 0.019 inch (0.483 mm) (No. 26 galvanized sheet).

  1503.3 Parapet walls. Parapet walls shall be coped or covered in accordance with Sections 1503.3.1 and 1503.3.2. The top surface of the parapet wall shall provide positive drainage.

  1503.3.1 Fire-resistance-rated parapet walls. Parapet walls required by Section 705.12 shall be coped or covered with weatherproof materials of a width not less than the thickness of the parapet wall such that the fire-resistance rating of the wall is not decreased.

  1503.3.2 Other parapet walls. Parapet walls meeting one of the exceptions in Section 705.12 shall be coped or covered with weatherproof materials of a width not less than the thickness of the parapet wall.

  1503.4 Attic and rafter ventilation. Intake and exhaust vents for ventilation of attic and enclosed rafter assemblies shall be provided in accordance with Section 1202.2 and the vent product manufacturer’s installation instructions.

• CBC § 1101.11 High relevance — show source text

  1101.11 Paved Areas. Where the occupant creates surface water drainage, the sumps, gratings, or floor drains shall be piped to a storm drain or an approved water course. 1101.12 Roof Drainage. Roof drainage shall comply with Section 1101.12.1 and Section 1101.12.2.

  1101.12.1 Primary Roof Drainage. Roof areas of a building shall be drained by roof drains or gutters. The location and sizing of drains and gutters shall be coordinated with the structural design and pitch of the roof. Unless otherwise required by the Authority Having Jurisdiction, roof drains, gutters, vertical conductors or leaders, and horizontal storm drains for primary drainage shall be sized based on a storm of 60 minutes duration and 100 year return period. Refer to Table D 101.1 (in Appendix D) for 100 years, 60-minute storms at various locations. 1101.12.2 Secondary Drainage. Secondary (emergency) roof drainage shall be provided by one of the methods specified in Section 1101.12.2.1 or Section 1101.12.2.2.

  1101.12.2.1 Roof Scuppers or Open Side. Secondary roof drainage shall be provided by an opensided roof or scuppers where the roof perimeter construction extends above the roof in such a manner that water will be entrapped. An open-sided roof or scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by Section 1101.12.1. Scupper openings shall be not less than 4 inches (102 mm) high and have a width equal to the circumference of the roof drain required for the area served, sized in accordance with Table 1103.1.

  1101.12.2.2 Secondary Roof Drain. Secondary roof drains shall be provided. The secondary roof drains shall be located not less than 2 inches (51 mm) above the roof surface. The maximum height of the roof drains shall be a height to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by Section 1101.12.1. The secondary roof drains shall connect to a piping system in accordance with Section 1101.12.2.2.1 or Section 1101.12.2.2.2.

  1101.12.2.2.1 Separate Piping System. The secondary roof drainage system shall be a

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  STORM DRAINAGE

  separate system of piping, independent of the primary roof drainage system. The discharge shall be above grade, in a location observable by the building occupants or maintenance personnel. Secondary roof drain systems shall be sized in accordance with Section 1101.12.1

  based on the rainfall rate for which the primary system is sized. 1101.12.2.2.2 Combined System. The secondary roof drains shall connect to the vertical piping of the primary storm drainage conductor downstream of the last horizontal offset located below the roof. The primary storm drainage system shall connect to the building storm water that connects to an underground public storm sewer. The combined secondary and primary roof drain systems shall be sized in accordance with Section 1103.0 based on double the rain fall rate for the local area.

• CBC § 1502.2 High relevance — show source text

  1||||X|X|||||||||||||||||||| |1502.2||||X|X|||||||||||||||||||| |1503.3 – 1503.4|||X|||||||||||||||||||||| |1505 – 1507|||X|||||||||||||||||||||| |1507.3.10||||||||X|X|X|X|X||X|X|||||||||| |1507.7.8||||||||X|X|X|X|X||X|X|||||||||| |1509 – 1511|||X|||||||||||||||||||||| |1511.9.6||||||X|X|||||||||||||||||| |1511.10– 1511.10.1|X|||X|X|||X|X|X|X|X||X|X|||||||||| |1512|||X|||||||||||||||||||||| |1513||||||||X|X|X|X|X||X|X||||||||||

  The state agency does not adopt sections identified by the following symbol:

  The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

  2025 CALIFORNIA BUILDING CODE 15-1

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  15-2 2025 CALIFORNIA BUILDING CODE

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  15 ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

  User notes:

  About this chapter: Chapter 15 provides minimum requirements for the design and construction of roof assemblies and rooftop structures. The criteria address the weather-protective barrier at the roof and, in most circumstances, a fire-resistant barrier. The chapter is largely prescriptive in nature and is based on decades of experience with various traditional materials, but it also recognizes newer products. Section 1511 addresses rooftop structures, which include penthouses, tanks, towers and spires. Rooftop penthouses larger than prescribed in this chapter must be treated as a story under Chapter 5.

  ICC code development note: Code change proposals to sections preceded by the designation [BF] or [P] will be considered by one of the code development committees meeting during the 2024 (Group A) Code Development Cycle. All other code change proposals will be considered by a code development committee meeting during the 2025 (Group B) Code Development Cycle.

  SECTION 1501—GENERAL

  1501.1 Scope. The provisions of this chapter shall govern the design, materials, construction and quality of roof assemblies, and rooftop structures.

  SECTION 1502—ROOF DRAINAGE

  [P] 1502.1 General. Design and installation of roof drainage systems shall comply with this section, Section 1611 of this code and Chapter 11 of the California Plumbing Code .

  [P] 1502.2 Secondary (emergency overflow) drains or scuppers. Where roof drains are required, secondary (emergency overflow) roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water will be entrapped if the primary drains allow buildup for any reason. The installation and sizing of secondary emergency overflow drains, leaders and conductors shall comply with Section 1611 of this code and Chapter 11 of the California Plumbing Code .

• CBC § 1101.7 High relevance — show source text

  (1) They do not serve continuously flowing springs or groundwater.

  (2) The point of discharge is not less than 10 feet (3048 mm) from a property line.

  (3) It is impracticable to discharge such drains to a storm drain, to an approved water course, to the front street curb or gutter, or to an alley. 1101.7 Building Subdrains. Building subdrains located below the public sewer level shall discharge into a sump or receiving tank, the contents of which shall be automatically lifted and discharged into the drainage system as required for building sumps. 1101.8 Areaway Drains. Open subsurface space adjacent to a building, serving as an entrance to the basement or cellar of a building, shall be provided with a drain or drains. The areaway drains shall be not less than 2 inches (50 mm) in diameter for areaways at a maximum of 100 square feet (9.29 m [2] ) in area, and shall be discharged in the manner provided for subsoil drains not serving continuously flowing springs or groundwater (see Section 1101.6.1). Areaways exceeding 100 square feet (9.29 m [2] ) shall not drain into subsoil drains.

  The drains for areaways exceeding 100 square feet (9.29 m [2] ) shall be sized in accordance with Table 1103.2.

  1101.9 Window Areaway Drains. Window areaways at a maximum of 10 square feet (0.93 m [2] ) in area shall be permitted to discharge to the subsoil drains through a 2 inch (50 mm) diameter pipe. However, window areaways exceeding 10 square feet (0.93 m [2] ) in area shall be handled in the manner provided for entrance areaways (see Section 1101.8). 1101.10 Filling Stations and Motor Vehicle Washing Establishments. Public filling stations and motor vehicle washing establishments shall have the paved area sloped toward sumps or gratings within the property lines. Curbs not less than 6 inches (152 mm) high shall be placed where required to direct water to gratings or sumps.

  1101.11 Paved Areas. Where the occupant creates surface water drainage, the sumps, gratings, or floor drains shall be piped to a storm drain or an approved water course. 1101.12 Roof Drainage. Roof drainage shall comply with Section 1101.12.1 and Section 1101.12.2.

  1101.12.1 Primary Roof Drainage. Roof areas of a building shall be drained by roof drains or gutters. The location and sizing of drains and gutters shall be coordinated with the structural design and pitch of the roof. Unless otherwise required by the Authority Having Jurisdiction, roof drains, gutters, vertical conductors or leaders, and horizontal storm drains for primary drainage shall be sized based on a storm of 60 minutes duration and 100 year return period. Refer to Table D 101.1 (in Appendix D) for 100 years, 60-minute storms at various locations. 1101.12.2 Secondary Drainage. Secondary (emergency) roof drainage shall be provided by one of the methods specified in Section 1101.12.2.1 or Section 1101.12.2.2.

• CBC § 1103.1 High relevance — show source text

  (3) Not less than two drains shall be installed in roof areas of 10 000 square feet (929 m [2] ) or less, and not less than one additional drain shall be installed for each 10 000 square feet (929 m [2] ) of roof area exceeding 10 000 square feet (929 m [2] ). (4) Each roof drain shall have a precalibrated, fixed (nonadjustable), and proportional weir (notched) in a standing water collar inside the strainer. No mechanical devices or valves shall be permitted. (5) Pipe sizing shall be based on the pre-calibrated rate of flow (gpm) (L/s) of the pre-calibrated weir for the maximum allowable water depth, and Table 1103.1 and Table 1103.2.

  (6) The height of stones or other granular material above the waterproofed surface shall not be considered in water depth measurement, and the roof surface in the vicinity of the drain shall not be recessed to create a reservoir.

  (7) Roof design, where controlled-flow roof drainage is used, shall be such that the design roof live load is not less than 30 lb/ft [2] (146 kg/m [2] ) to provide a safety factor exceeding the 15 lb/ft [2] (73 kg/m [2] ) represented by the depth of water stored on the roof in accordance with Table 1105.1(1). (8) Scuppers shall be provided in parapet walls. The distance of scupper bottoms above the roof level at the drains shall not exceed the maximum distances specified in Table 1105.1(2).

  (9) Scupper openings shall be not less than 4 inches (102 mm) high and have a width equal to the circumference of

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  STORM DRAINAGE

  the roof drain required for the area served, sized in accordance with Table 1103.1.

  (10)Flashings shall extend above the top of the scuppers.

  (11)At a wall or parapet, 45 degree (0.79 rad) cants shall be installed.

  (12)Separate storm and sanitary drainage systems shall be provided within the building.

  (13)Calculations for the roof drainage system shall be submitted along with the plans to the Authority Having Jurisdiction for approval.

  TABLE 1105.1(1) CONTROLLED-FLOW MAXIMUM ROOF WATER DEPTH

  ROOF RISE* (inches)	MAXIMUM WATER DEPTH AT DRAIN (inches)
  Flat	3
  2	4
  4	5
  6	6

  For SI units: 1 inch = 25.4 mm

  • Vertical measurement from the roof surface at the drain to the highest point of the roof surface served by the drain, ignoring a local depression immediately adjacent to the drain.

  TABLE 1105.1(2) DISTANCE OF SCUPPER BOTTOMS ABOVE ROOF

• CBC § 2.1 High relevance — show source text

  R903.2.1 Locations. Flashings shall be installed at wall and roof intersections, wherever there is a change in roof slope or direction and around roof openings. A flashing shall be installed to divert the water away from where the eave of a sloped roof intersects a vertical sidewall. Where flashing is of metal, the metal shall be corrosion resistant with a thickness of not less than 0.019 inch (0.5 mm) (No. 26 galvanized sheet).

  R903.2.2 Crickets and saddles. A cricket or saddle shall be installed on the ridge side of any chimney or penetration more than 30 inches (762 mm) wide as measured perpendicular to the slope. Cricket or saddle coverings shall be sheet metal or of the same material as the roof covering.

  Exception: Unit skylights installed in accordance with Section R324.6 and flashed in accordance with the manufacturer’s instructions shall be permitted to be installed without a cricket or saddle.

  R903.3 Coping. Parapet walls shall be properly coped with noncombustible, weatherproof materials of a width not less than the thickness of the parapet wall.

  R903.4 Roof drainage. Unless roofs are sloped to drain over roof edges, roof drains shall be installed at each low point of the roof.

  R903.4.1 Secondary (emergency overflow) drains or scuppers. Where roof drains are required, secondary emergency overflow roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water will be entrapped if the primary drains allow buildup for any reason. Overflow drains having the same size as the roof drains shall be installed with the inlet flow line located 2 inches (51 mm) above the low point of the roof, or overflow scuppers having three times the size of the roof drains and having a minimum opening height of 4 inches (102 mm) shall be installed in the adjacent parapet walls with the inlet flow located 2 inches (51 mm) above the low point of the roof served. The installation and sizing of overflow drains, leaders and conductors shall comply with the California Plumbing Code .

  SECTION R904—MATERIALS

  R904.1 Scope. The requirements set forth in this section shall apply to the application of roof covering materials specified herein. Roof assemblies shall be applied in accordance with this chapter and the manufacturer’s installation instructions. Installation of roof assemblies shall comply with the applicable provisions of Section R905.

  R904.2 Compatibility of materials. Roof assemblies shall be of materials that are compatible with each other and with the building or structure to which the materials are applied.

  R904.3 Material specifications and physical characteristics. Roof covering materials shall conform to the applicable standards listed in this chapter.

  R904.4 Product identification. Roof covering materials shall be delivered in packages bearing the manufacturer’s identifying marks and approved testing agency labels required. Bulk shipments of materials shall be accompanied by the same information issued in the form of a certificate or on a bill of lading by the manufacturer.

  SECTION R905—REQUIREMENTS FOR ROOF COVERINGS

  R905.1 Roof covering application. Roof coverings shall be applied in accordance with the applicable provisions of this section and the manufacturer’s installation instructions. Unless otherwise specified in this section, roof coverings shall be installed to resist the component and cladding loads specified in Table R301.2.1(1), adjusted for height and exposure in accordance with Table R301.2.1(2).

• CBC § 1101.16 Medium relevance — show source text

  1101.16 Leaders, Conductors, and

  Connections . . . . . . . . . . . . . . . . .207

  1102.0 Roof Drains . . . . . . . . . . . . . . . . . .207

  1102.1 Applications . . . . . . . . . . . . . . . . .207

  1102.2 Dome Strainers Required . . . . . . .207

  1102.3 Roof Drain Flashings . . . . . . . . . .207

  1103.0 Size of Leaders, Conductors,

  and Storm Drains . . . . . . . . . . . . .207

  1103.1 Vertical Conductors and

  Leaders . . . . . . . . . . . . . . . . . . . . .207

  1103.2 Size of Horizontal Storm

  Drains and Sewers . . . . . . . . . . . .207

  1103.3 Size of Roof Gutters . . . . . . . . . . .207

  1103.4 Side Walls Draining onto a Roof . . . . . . . . . . . . . . . . . .207

  Table 1103.1 Sizing Roof Drains, Leaders, and Vertical Rainwater Piping . . .208

  1104.0 Values for Continuous Flow . . . . .208

  1104.1 General . . . . . . . . . . . . . . . . . . . . .208

  1105.0 Controlled-Flow Roof

  Drainage . . . . . . . . . . . . . . . . . . . .208

  1105.1 Application . . . . . . . . . . . . . . . . . .208

  Table 1105.1(1) Controlled-Flow Maximum Roof Water Depth . . . . . . . . . . . . .209

  Table 1105.1(2) Distance of Scupper Bottoms Above Roof . . . . . . . . . . . . . . . . . .209

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  TABLE OF CONTENTS

  1105.2 Setback Roofs . . . . . . . . . . . . . . .209

  1106.0 Engineered Storm Drainage System . . . . . . . . . . . . . . . . . . . . .209

  1106.1 General . . . . . . . . . . . . . . . . . . . . .209

  1106.2 Siphonic Roof Drainage Systems . . . . . . . . . . . . . . . . . . . .209

  1106.3 Siphonic Roof Drains . . . . . . . . . .209

  1107.0 Testing . . . . . . . . . . . . . . . . . . . . .209

  1107.1 Testing Required . . . . . . . . . . . . .209

  1107.2 Methods of Testing Storm Drainage Systems . . . . . . . . . . . .209

  Table 1103.2 Sizing of Horizontal Rainwater Piping . . . . . . . . . . . . .210

  Table 1103.3 Size of Gutters . . . . . . . . . . . . . . .211

• CBC § 1101.1 Medium relevance — show source text

  1101.1 Applicability . . . . . . . . . . . . . . . . . .205

  1101.2 Where Required . . . . . . . . . . . . . .205

  1101.3 Storm Water Drainage to Sanitary Sewer Prohibited . . . . . .205

  1101.4 Material Uses . . . . . . . . . . . . . . . .205

  Table 1101.4.6 Materials for Subsoil Drainpipe and Fittings . . . . . . . . . . . . . . . . . .205

  1101.5 Expansion Joints Required . . . . . .205

  1101.6 Subsoil Drains . . . . . . . . . . . . . . .205

  1101.7 Building Subdrains . . . . . . . . . . . .206

  1101.8 Areaway Drains . . . . . . . . . . . . . .206

  1101.9 Window Areaway Drains . . . . . . .206

  1101.10 Filling Stations and Motor Vehicle Washing Establishments . . . . . . . . . . . . . . .206

  1101.11 Paved Areas . . . . . . . . . . . . . . . . .206

  1101.12 Roof Drainage . . . . . . . . . . . . . . .206

  1101.13 Cleanouts . . . . . . . . . . . . . . . . . . .207

  1101.14 Rainwater Sumps . . . . . . . . . . . . .207

  1101.15 Traps on Storm Drains and Leaders . . . . . . . . . . . . . . . . . . . . .207

  1101.16 Leaders, Conductors, and

  Connections . . . . . . . . . . . . . . . . .207

  1102.0 Roof Drains . . . . . . . . . . . . . . . . . .207

  1102.1 Applications . . . . . . . . . . . . . . . . .207

  1102.2 Dome Strainers Required . . . . . . .207

  1102.3 Roof Drain Flashings . . . . . . . . . .207

  1103.0 Size of Leaders, Conductors,

  and Storm Drains . . . . . . . . . . . . .207

  1103.1 Vertical Conductors and

  Leaders . . . . . . . . . . . . . . . . . . . . .207

  1103.2 Size of Horizontal Storm

  Drains and Sewers . . . . . . . . . . . .207

  1103.3 Size of Roof Gutters . . . . . . . . . . .207

  1103.4 Side Walls Draining onto a Roof . . . . . . . . . . . . . . . . . .207

  Table 1103.1 Sizing Roof Drains, Leaders, and Vertical Rainwater Piping . . .208

  1104.0 Values for Continuous Flow . . . . .208

  1104.1 General . . . . . . . . . . . . . . . . . . . . .208

  1105.0 Controlled-Flow Roof

  Drainage . . . . . . . . . . . . . . . . . . . .208

• CBC § 1103.1. Medium relevance — show source text

  (9) Scupper openings shall be not less than 4 inches (102 mm) high and have a width equal to the circumference of

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  STORM DRAINAGE

  the roof drain required for the area served, sized in accordance with Table 1103.1.

  (10)Flashings shall extend above the top of the scuppers.

  (11)At a wall or parapet, 45 degree (0.79 rad) cants shall be installed.

  (12)Separate storm and sanitary drainage systems shall be provided within the building.

  (13)Calculations for the roof drainage system shall be submitted along with the plans to the Authority Having Jurisdiction for approval.

  TABLE 1105.1(1) CONTROLLED-FLOW MAXIMUM ROOF WATER DEPTH

  ROOF RISE* (inches)	MAXIMUM WATER DEPTH AT DRAIN (inches)
  Flat	3
  2	4
  4	5
  6	6

  For SI units: 1 inch = 25.4 mm

  • Vertical measurement from the roof surface at the drain to the highest point of the roof surface served by the drain, ignoring a local depression immediately adjacent to the drain.

  TABLE 1105.1(2) DISTANCE OF SCUPPER BOTTOMS ABOVE ROOF

  ROOF RISE* (inches)	ABOVE ROOF LEVEL AT DRAIN (inches)
  Flat	3
  2	4
  4	5
  6	6

  For SI units: 1 inch = 25.4 mm

  • Vertical measurement from the roof surface at the drain to the highest point of the roof surface served by the drain, ignoring a local depression immediately adjacent to the drain.

  1105.2 Setback Roofs. Drains on setback roofs shall be permitted to be connected to the controlled-flow drainage systems provided:

  (1) The setback is designed for storing water, or

  (2) The square footage of the setback drainage area is converted as outlined in Section 1105.0 to gpm, and the storm-water pipe sizes in the controlled-flow system are based on the sum of the loads.

  (3) The branch from each of the roof drains that are not provided with controlled flow shall be sized in accordance

  with Table 1103.1.

  1106.0 Engineered Storm Drainage System. 1106.1 General. The design and sizing of a storm drainage system shall be permitted to be determined by accepted engineering practices. The system shall be designed by a regis

  TABLE 1105.1(1) CONTROLLED-FLOW MAXIMUM ROOF WATER DEPTH

  For SI units: 1 inch = 25.4 mm

  • Vertical measurement from the roof surface at the drain to the highest point of the roof surface served by the drain, ignoring a local depression immediately adjacent to the drain.

  TABLE 1105.1(2) DISTANCE OF SCUPPER BOTTOMS ABOVE ROOF

  For SI units: 1 inch = 25.4 mm

• CBC § 4-1 Medium relevance — show source text

  The state agency does not adopt sections identified by the following symbol: †.

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  4 RESIDENTIAL MANDATORY MEASURES

  DIVISION 4.1 – PLANNING AND DESIGN

  SECTION 4.101—GENERAL

  4.101.1 Scope. The provisions of this division outline planning, design and development methods that include environmentally responsible site selection, building design, building siting and development to protect, restore and enhance the environmental quality of the site and respect the integrity of adjacent properties.

  SECTION 4.102—DEFINITIONS

  4.102.1 Definitions. The following terms are defined in Chapter 2.

  FRENCH DRAIN.

  WATTLES.

  SECTION 4.103—SITE SELECTION (RESERVED)

  SECTION 4.104—SITE PRESERVATION (RESERVED)

  SECTION 4.105—DECONSTRUCTION AND REUSE OF EXISTING STRUCTURES (RESERVED)

  SECTION 4.106—SITE DEVELOPMENT

  4.106.1 General. Preservation and use of available natural resources shall be accomplished through evaluation and careful planning to minimize negative effects on the site and adjacent areas. Preservation of slopes, management of storm water drainage and erosion controls shall comply with this section.

  4.106.2 Storm water drainage and retention during construction. Projects which disturb less than one acre of soil and are not part of a larger common plan of development which in total disturbs one acre or more, shall manage storm water drainage during construction. In order to manage storm water drainage during construction, one or more of the following measures shall be implemented to prevent flooding of adjacent property, prevent erosion and retain soil runoff on the site.

  1. Retention basins of sufficient size shall be utilized to retain storm water on the site.

  2. Where storm water is conveyed to a public drainage system, collection point, gutter or similar disposal method, water shall be filtered by use of a barrier system, wattle or other method approved by the enforcing agency.

  3. Compliance with a lawfully enacted storm water management ordinance.

  Note: Refer to the State Water Resources Control Board for projects which disturb one acre or more of soil, or are part of a larger common plan of development which in total disturbs one acre or more of soil.

  (Website: https://www.waterboards.ca.gov/water_issues/programs/stormwater/construction.html)

  4.106.3 Grading and paving. Construction plans shall indicate how the site grading or drainage system will manage all surface water flows to keep water from entering buildings. Examples of methods to manage surface water include, but are not limited to, the following:

  1. Swales

  2. Water collection and disposal systems

  3. French drains

  4. Water retention gardens

  5. Other water measures which keep surface water away from buildings and aid in groundwater recharge.

  Exception: Additions and alterations not altering the drainage path.

• CBC § 702.7 Medium relevance — show source text

  702.7 Materials and methods. New work shall comply with the materials and methods requirements in the California Building Code, California Energy Code, California Mechanical Code and California Plumbing Code, as applicable, that specify material standards, detail of installation and connection, joints, penetrations and continuity of any element, component or system in the building.

  SECTION 703—FIRE PROTECTION

  703.1 General. Alterations shall be done in a manner that maintains the level of fire protection provided.

  703.2 Fire alarm and detection.

  703.2.1 Replacement devices, combinations of devices, appliances, and equipment shall be listed and approved.

  703.2.2 Systems out of service. Existing fire alarm and detection systems shall be maintained in accordance with Section 901.7 of the California Fire Code, C.C.R. Title 24, Part 9.

  703.3 Construction in existing buildings. On-site fire protection during construction shall be in accordance with Chapter 33 of the Cali- fornia Building Code, C.C.R. Title 24, Part 2, and California Fire Code, C.C.R. Title 24, Part 9.

  SECTION 704—MEANS OF EGRESS

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

  704.2 Casework. Addition, alteration or reconfiguration of nonfixed and movable cases, counters and partitions not over 5 feet 9 inches (1753 mm) in height shall maintain the required means of egress path.

  704.3 Locking arrangements in educational occupancies. In Group E occupancies, Group B educational occupancies and Group I4 occupancies, egress doors with locking arrangements designed to keep intruders from entering the room shall comply with Section 1010.2.7 of the California Building Code .

  SECTION 705—REROOFING

  [BS] 705.1 General. Materials and methods of application used for recovering or replacing an existing roof covering shall comply with the requirements of Chapter 15 of the California Building Code .

  Exceptions:

  1. Roof replacement or roof recover of existing low-slope roof coverings shall not be required to meet the minimum design slope requirement of [1] / 4 unit vertical in 12 units horizontal (2-percent slope) in Section 1507 of the California Building Code for roofs that provide positive roof drainage and meet the requirements of Sections 1608.3 and 1611.2 of the Cali- fornia Building Code .
  2. Recovering or replacing an existing roof covering shall not be required to meet the requirement for secondary (emergency overflow) drains or scuppers in Section 1502 of the California Building Code for roofs that provide for positive roof drainage and meet the requirements of Sections 1608.3 and 1611.2 of the California Building Code . For the purposes of this exception, existing secondary drainage or scupper systems required in accordance with this code shall not be removed unless they are replaced by secondary drains or scuppers designed and installed in accordance with Section 1502 of the California Building Code .

  [BS] 705.2 Roof replacement. Roof replacement shall include the removal of all existing layers of roof coverings down to the roof deck.

• CBC § 1603.1.7 Medium relevance — show source text

  ** The design load-bearing values of soils shall be shown on the construction documents. 1603.1.7 Flood design data. For buildings located in whole or in part in flood hazard areas as established in Section 1612.3, the documentation pertaining to design, if required in Section 1612.4, shall be included and the following information, referenced to the datum on the community’s Flood Insurance Rate Map (FIRM), shall be shown, regardless of whether flood loads govern the design of the building:

  1. Flood design class assigned according to ASCE 24.
  2. In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation of the proposed lowest floor, including the basement.
  3. In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation to which any nonresidential building will be dry floodproofed.
  4. In coastal high hazard areas and coastal A zones, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.

  1603.1.8 Special loads. Special loads that are applicable to the design of the building, structure or portions thereof, including but not limited to the loads of machinery or equipment, and that are greater than specified floor and roof loads shall be specified by their descriptions and locations.

  1603.1.8.1 Photovoltaic panel systems. The dead load of rooftop-mounted photovoltaic panel systems, including rack support systems, shall be indicated on the construction documents.

  1603.1.9 Roof rain load data. Design rainfall intensity, i (in/hr) (cm/hr), and roof drain, scupper and overflow locations shall be shown regardless of whether rain loads govern the design.

  SECTION 1604—GENERAL DESIGN REQUIREMENTS

  1604.1 General. Building, structures and parts thereof shall be designed and constructed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods, as permitted by the applicable material chapters and referenced standards.

  1604.2 Strength. Buildings and other structures, and parts thereof, shall be designed and constructed to support safely the factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other structures, and parts thereof, shall be designed and constructed to support safely the nominal loads in load combinations defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.

  Loads and forces for occupancies or uses not covered in this chapter shall be subject to the approval of the building official.

  1604.3 Serviceability. Structural systems and members thereof shall be designed to have adequate stiffness to limit deflections as indicated in Table 1604.3.