CBC · California Building Code
Site construction (footings, slabs, shotcrete) and existing-concrete rules
This hub orients you to the CBC provisions for site concrete (footings, slabs, shotcrete) and the code’s requirements for testing and reusing existing concrete, with pointers to the primary sections and referenced standards.
Last reviewed: July 5, 2026
Overview
This area of the California Building Code (CBC) covers concrete work at the site that establishes the building’s support and ground-level finishes — spread footings and prescriptive footing rules for light‑frame work, slabs‑on‑ground (structural and nonstructural), and shotcrete practice and testing — plus the rules that govern reuse or rehabilitation of in‑place concrete. The requirements live primarily in Chapter 19 (Concrete) and its California amendments (Chapter 19A), with close cross‑references to the soils & foundations chapters and special‑inspection rules in Chapter 17. See, for example, the Chapter 19 table of contents and the listings for §§1906, 1907 and 1908 in the CBC for the core topics covered here .
Key prescriptive items to watch for on site work include minimum slab thickness and moisture‑control measures for slabs‑on‑grade (see §1907.3 and §1907.4 regarding 3 1/2‑inch minimum thickness and vapor retarders) ; rules for plain footings in light‑frame buildings under §1906 and the related soil/foundation seismic tie requirements in Chapter 18 (§1809.13) file; and shotcrete requirements that adopt and modify ACI 318 and ACI 506 with mandatory mockups, testing and special inspection per the CBC (see §1908 and the ACI modifications in the code) file. Existing‑concrete rehabilitation rules require representative coring and prohibit reuse of in‑place concrete below minimum in‑place strength (the code limits structural use of concrete with core strengths under about 1,500 psi and specifies sampling rates) .
In this section
- What are the CBC rules for slabs-on-ground (design, diaphragm, special cases)?
- What are the special provisions for existing concrete (core testing, epoxy injection, FRP strengthening)?
- What code provisions govern shotcrete (materials, placement, testing)?
- What does the CBC require for footings in light‑frame construction?
Code references
Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:
CBC § 1907.2 High relevance — show source text
1907.2 Nonstructural slabs-on-ground. Nonstructural slabs-on-ground shall be required to comply with Sections 1904.2, 1907.3 and 1907.4. Portions of the nonstructural slabs-on-ground used to resist uplift forces or overturning shall be designed in accordance with accepted engineering practice throughout the entire portion designated as dead load to resist uplift forces or overturning. 1907.3 Thickness. The thickness of concrete floor slabs supported directly on the ground shall be not less than 3 [1] / 2 inches (89 mm).
1907.4 Vapor retarder. A 6-mil (0.006 inch; 0.15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete floor slab, or other approved equivalent methods or materials shall be used to retard vapor transmission through the floor slab.
Exception: A vapor retarder is not required:
For detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities.
For unheated storage rooms having an area of less than 70 square feet (6.5 m [2] ) and carports attached to occupancies in Group R-3.
For buildings of other occupancies where migration of moisture through the slab from below will not be detrimental to the intended occupancy of the building.
For driveways, walks, patios and other flatwork that will not be enclosed at a later date.
Where approved based on local site conditions.
1907.4.1 [HCD 1] Capillary break. When a vapor retarder is required, a capillary break shall be installed in accordance with the Cali- fornia Green Building Standards Code (CALGreen), Chapter 4, Division 4.5.
SECTION 1908—SHOTCRETE
1908.1 General. Shotcrete shall be in accordance with the requirements of ACI 318. [OSHPD 1R, 2 & 5] and the provisions of ACI 506R.
Preconstruction tests of one or more shotcrete mockup panels prepared in accordance with Section 1705.3.9.2 are required. In addi- tion to testing requirements in ACI 318, special inspection and testing shall be in accordance with Section 1705.3.9.
The evaluation of the shotcrete mockup panel to qualify bar clearance dimensions in accordance with ACI 318 Section 25.2.7 or contact lap splices in accordance with ACI 318 Section 25.5.1.7 shall be in accordance with the requirements of ACI 506.4R with a core quality category of Very Good given in ACI 506.6T.
Shotcrete construction shall be in accordance with the requirements of ACI 506.2.
SECTION 1909—ADDITIONAL REQUIREMENTS FOR COMMUNITY COLLEGES [DSA-SS/CC]
1909.1 General.
1909.1.1 Construction documents. Openings larger than 12 inches (305 mm) in any dimension shall be detailed on the structural drawings.
1909.2 Tests and materials. Where required, special inspections and tests shall be in accordance with Chapter 17A and this section. 1909.2.1 Steel fiber reinforcement - Not permitted.
CBC § 18A-11 High relevance — show source text
1808A Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18A-11
1809A Shallow Foundations. . . . . . . . . . . . . . . . . . . . . . . . . . . 18A-14
1810A Deep Foundations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18A-15
1811A Prestressed Rock and Soil Foundation
Anchors [OSHPD 1R, 2 & 5] . . . . . . . . . . . . . . . . . . . . 18A-25
1812A Earth Retaining Shoring . . . . . . . . . . . . . . . . . . . . . . . . 18A-26
1813A Vibro Stone Columns for Ground
Improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18A-29
CHAPTER 19 CONCRETE. . . . . . . . . . . . . . . . . . . . . . . . . . . 19-1
1901 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-3
1902 Coordination of Terminology . . . . . . . . . . . . . . . . . . . 19-5
1903 Specifications for Tests and Materials . . . . . . . . . . . 19-5
1904 Durability Requirements . . . . . . . . . . . . . . . . . . . . . . . 19-6
1905 Seismic Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 19-6
1906 Footings for Light-Frame Construction . . . . . . . . . . 19-8
1907 Slabs-on-Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-8
1908 Shotcrete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-8
1909 Additional Requirements for Community Colleges
[DSA-SS/CC]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19-8
1910 Additional Requirements for Skilled Nursing Facilities, Intermediate Care Facilities, Acute Psychiatric and Non-GAC Buildings
[OSHPD 1R, 2 & 5]. . . . . . . . . . . . . . . . . . . . . . . . . . . . .19-12
1911 Existing Concrete Structures [OSHPD 1R, 2 & 5]. . . . . . .19-13
CBC § 2.4. High relevance — show source text
2.4. Anchors are located a minimum of 15 anchor diameters from the edge of the concrete perpendicular to the length of the track. 2.5. The track is 33 to 68 mil (0.84 mm to 1.73 mm) designation thickness. 3. In light-frame construction bearing or nonbearing walls, shear strength of concrete anchors less than or equal to 1 inch (25 mm) in diameter attaching sill plate or track to foundation or foundation stemwalls need not satisfy Sections 17.10.6.3(a) through (c) when the design strength of the anchors is determined in accordance with Section 17.7.2.1(c) of ACI 318.
SECTION 1906—FOOTINGS FOR LIGHT-FRAME CONSTRUCTION
[OSHPD 1R, 2 & 5] Plain concrete footings not permitted by OSHPD.
1906.1 Plain concrete footings. For Group R-3 occupancies and buildings of other occupancies less than two stories above grade plane of light-frame construction, the required thickness of plain concrete footings is permitted to be 6 inches (152 mm), provided that the footing does not extend more than 4 inches (102 mm) on either side of the supported wall.
SECTION 1907—SLABS-ON-GROUND
1907.1 Structural slabs-on-ground. Structural concrete slabs-on-ground shall comply with all applicable provisions of this chapter. Slabs-on-ground shall be considered structural concrete where required by ACI 318 or where designed to transmit either of the following:
- Vertical loads or lateral forces from other parts of the structure to the soil.
- Vertical loads or lateral forces from other parts of the structure to foundations.
1907.2 Nonstructural slabs-on-ground. Nonstructural slabs-on-ground shall be required to comply with Sections 1904.2, 1907.3 and 1907.4. Portions of the nonstructural slabs-on-ground used to resist uplift forces or overturning shall be designed in accordance with accepted engineering practice throughout the entire portion designated as dead load to resist uplift forces or overturning. 1907.3 Thickness. The thickness of concrete floor slabs supported directly on the ground shall be not less than 3 [1] / 2 inches (89 mm).
1907.4 Vapor retarder. A 6-mil (0.006 inch; 0.15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete floor slab, or other approved equivalent methods or materials shall be used to retard vapor transmission through the floor slab.
Exception: A vapor retarder is not required:
For detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities.
For unheated storage rooms having an area of less than 70 square feet (6.5 m [2] ) and carports attached to occupancies in Group R-3.
For buildings of other occupancies where migration of moisture through the slab from below will not be detrimental to the intended occupancy of the building.
For driveways, walks, patios and other flatwork that will not be enclosed at a later date.
Where approved based on local site conditions.
CBC § 19A-5 High relevance — show source text
2025 CALIFORNIA BUILDING CODE 19A-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CONCRETE
1907 A .2 Nonstructural slabs-on-ground. Nonstructural slabs-on-ground shall be required to comply with Sections 1904 A .2, 1907 A .3 and 1907 A .4. Portions of the nonstructural slabs-on-ground used to resist uplift forces or overturning shall be designed in accordance with accepted engineering practice throughout the entire portion designated as dead load to resist uplift forces or overturning. 1907 A .3 Thickness. The thickness of concrete floor slabs supported directly on the ground shall be not less than 3 [1] / 2 inches (89 mm).
1907 A .4 Vapor retarder. A 6-mil (0.006 inch; 0.15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete floor slab, or other approved equivalent methods or materials shall be used to retard vapor transmission through the floor slab.
Exception: A vapor retarder is not required:
For detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities.
For unheated storage rooms having an area of less than 70 square feet (6.5 m [2] ) and carports attached to occupancies in Group R-3.
For buildings of other occupancies where migration of moisture through the slab from below will not be detrimental to the intended occupancy of the building.
For driveways, walks, patios and other flatwork that will not be enclosed at a later date.
Where approved based on local site conditions.
SECTION 1908 A —SHOTCRETE
1908 A .1 General. Shotcrete shall be in accordance with the requirements of ACI 318 and the provisions of ACI 506R. Preconstruction tests of one or more shotcrete mockup panels prepared in accordance with Section 1705A.3.9.2 are required. In addition to testing requirements in ACI 318, special inspection and testing shall be in accordance with Section 1705A.3.9. The evaluation of the shotcrete mockup panel to qualify bar clearance dimensions in accordance with ACI 318 Section 25.2.7 or contact lap splices in accordance with ACI 318 Section 25.5.1.7 shall be in accordance with the requirements of ACI 506.4R with a core quality category of Very Good given in ACI 506.6T.
Shotcrete construction shall be in accordance with the requirements of ACI 506.2.
SECTION 1909A—MODIFICATIONS TO ACI 318
1909A.1 General. The text of ACI 318 shall be modified as indicated in Sections 1909A.1.1 through 1909A.1.16.
1909A.1.1 ACI 318, Section 4.12.2.2. Modify ACI 318, Section 4.12.2.2 by adding the following:
CBC § 19-5 High relevance — show source text
1903 Specifications for Tests and Materials . . . . . . . . . . . 19-5
1904 Durability Requirements . . . . . . . . . . . . . . . . . . . . . . . 19-6
1905 Seismic Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 19-6
1906 Footings for Light-Frame Construction . . . . . . . . . . 19-8
1907 Slabs-on-Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-8
1908 Shotcrete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-8
1909 Additional Requirements for Community Colleges
[DSA-SS/CC]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19-8
1910 Additional Requirements for Skilled Nursing Facilities, Intermediate Care Facilities, Acute Psychiatric and Non-GAC Buildings
[OSHPD 1R, 2 & 5]. . . . . . . . . . . . . . . . . . . . . . . . . . . . .19-12
1911 Existing Concrete Structures [OSHPD 1R, 2 & 5]. . . . . . .19-13
CHAPTER 19A CONCRETE . . . . . . . . . . . . . . . . . . . . . . . . . . 19A-1
1901A General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-3
1902A Coordination of Terminology . . . . . . . . . . . . . . . . . . . .19A-4
1903A Specifications for Tests and Materials . . . . . . . . . . . .19A-4
1904A Durability Requirements . . . . . . . . . . . . . . . . . . . . . . . .19A-4
1905A Seismic Requirements . . . . . . . . . . . . . . . . . . . . . . . . . .19A-4
1906A Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-5
1907A Slabs-on-Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-5
1908A Shotcrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-6
1909A Modifications to ACI 318. . . . . . . . . . . . . . . . . . . . . . . . .19A-6
CBC § 1603.1 High relevance — show source text
Construction documents 1603.1,
1901.5 Durability 1904 Footings 1809, 1906 Foundation walls 1807.1.5, 1808.8 Materials 1705.3.2, 1901, 1903 Plain, structural 1906 Reinforced gypsum concrete 2514 Rodentproofing Appendix F Roof tile 1504.3, 1507.3, 1513 Shotcrete 1908 Slabs-on-ground 1907 Special inspections 1705.3, Table 1705.3 Specifications 1903 Strength testing 1705.3.2 Structural concrete with GFRP
reinforcement 1901.2.1 Wood support 2304.13 Concrete Masonry Calculated fire resistance 722.3
Construction 2104
Design 2101.2, 2108, 2109 Materials 2103.1 Surface bonding 2103.2.2, 2109.2 Wood support 2304.13 Concrete Roof Tile 1504.3, 1507.3, 1513 Wind Resistance 1504.3, 1609.6.3.1 Condominium (see Apartment Houses) Conduit, Penetration Protection 713.3,
1023.5 Conflicts in Code 102, 104.2.4.1 Congregate Living Facilities 310.2, 310.3, 310.4
Construction (See Safeguards During Construction) Construction Documents 107, 1603 Alarms and detection 907.1.1
Balconies 107.2.5
Concrete construction 1901.5 Design load-bearing capacity 1803.6 Exterior walls 107.2.4
Fire protection 107.2.2 Fire-resistant joint systems 715 Flood 107.2.6.1, 1603.1.7 Floor live load 1603.1.1
Geotechnical 1603.1.6 Means of egress 107.2.3
INDEX-4 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
Parking structures 402.4.1.3, 402.4.2.3 Perimeter line 402.1.1 Play structures 402.6.3, 424 Separation 402.4.2 Signs 402.6.4 Smoke control 402.7.2 Sprinkler protection 402.5 Standby power 402.7.3 Standpipe system 402.7.1, 905.3.3 Travel distance 402.8.5, 1006.2.1, 1006.3, 1017.2 Covered Walkway (see Pedestrian Walkway) 3104, 3306.7 Crawl Space
Access 1209.1
Drainage 1805.1.2 Unusable space fire protection 711.2.6 Ventilation 1202.4 Cripple Wall 2308.10.6, 2308.10.8.3, 2308.2.7, 2308.9.6 Cross-Laminated Timber 602.4, 602.4.4.2,
2303.1.4
CBC § 1809.13 Medium relevance — show source text
1809.13 Footing seismic ties. Where a structure is assigned to Seismic Design Category D, E or F, individual spread footings founded on soil defined in Chapter 20 of ASCE 7 as Site Class E or F shall be interconnected by ties. Unless it is demonstrated that equivalent restraint is provided by reinforced concrete beams within slabs on grade or reinforced concrete slabs on grade, ties shall be capable of carrying, in tension or compression, a force equal to the lesser of the product of the larger footing design gravity load times the seismic coefficient, S DS, divided by 10 and 25 percent of the smaller footing design gravity load.
1809.14 Grade beams. Grade beams shall comply with the provisions of ACI 318.
Exception: Grade beams not subject to differential settlement exceeding one-fourth of the thresholds specified in ASCE 7 Table 12.13-3 and designed to resist the seismic load effects including overstrength factor in accordance with Section 2.3.6 or 2.4.5 of ASCE 7 need not comply with ACI 318 Section 18.13.3.1.
1809.15 Pipes and Trenches. [OSHPD 1R, 2 & 5] Unless otherwise recommended by the soils report, open or backfilled trenches parallel with a footing shall not be below a plane having a downward slope of 1 unit vertical to 2 units horizontal (50-percent slope) from a line 9 inches (229 mm) above the bottom edge of the footing, and not closer than 18 inches (457 mm) from the face of such footing.
Where pipes cross under footings, the footings shall be specially designed. Pipe sleeves shall be provided where pipes cross through footings or footing walls and sleeve clearances shall provide for possible footing settlement, but not less than 1 inch (25 mm) all around pipe.
Exception: Alternate trench locations and pipe clearances shall be permitted when approved by registered design professional and the enforcement agent.
SECTION 1810—DEEP FOUNDATIONS
1810.1 General. Deep foundations shall be analyzed, designed, detailed and installed in accordance with Sections 1810.1 through 1810.4.
1810.1.1 Geotechnical investigation. Deep foundations shall be designed and installed on the basis of a geotechnical investigation as set forth in Section 1803.
1810.1.2 Use of existing deep foundation elements. Deep foundation elements left in place where a structure has been demolished shall not be used for the support of new construction unless satisfactory evidence is submitted to the building official, which indicates that the elements are sound and meet the requirements of this code. Such elements shall be load tested or redriven to verify their capacities. The design load applied to such elements shall be the lowest allowable load as determined by tests or redriving data.
18-20 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
SOILS AND FOUNDATIONS
1810.1.3 Deep foundation elements classified as columns. Deep foundation elements standing unbraced in air, water or fluid soils shall be classified as columns and designed as such in accordance with the provisions of this code from their top down to the point where adequate lateral support is provided in accordance with Section 1810.2.1.
CBC § 19A-3 Medium relevance — show source text
1901A General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-3
1902A Coordination of Terminology . . . . . . . . . . . . . . . . . . . .19A-4
1903A Specifications for Tests and Materials . . . . . . . . . . . .19A-4
1904A Durability Requirements . . . . . . . . . . . . . . . . . . . . . . . .19A-4
1905A Seismic Requirements . . . . . . . . . . . . . . . . . . . . . . . . . .19A-4
1906A Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-5
1907A Slabs-on-Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-5
1908A Shotcrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19A-6
1909A Modifications to ACI 318. . . . . . . . . . . . . . . . . . . . . . . . .19A-6
1910A Concrete, Reinforcement and Anchor Testing . . . . .19A-9
1911A Existing Concrete Structures. . . . . . . . . . . . . . . . . . . 19A-10
CHAPTER 20 ALUMINUM . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1
2001 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-3
2002 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-3
2003 Testing and Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . .20-3
CHAPTER 21 MASONRY . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-1
2101 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-3
2102 Notations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-4
2103 Masonry Construction Materials . . . . . . . . . . . . . . . . 21-4
CBC § 1.3. Medium relevance — show source text
The maximum anchor nominal diameter is [5] / 8 inch (16 mm). 1.3. Anchor bolts are embedded into concrete not less than 7 inches (178 mm). 1.4. Anchor bolts are located not less than 1¾ inches (45 mm) from the edge of the concrete parallel to the length of the wood sill plate. 1.5. Anchor bolts are located not less than 15 anchor diameters from the edge of the concrete perpendicular to the length of the wood sill plate. 1.6. The sill plate is 2-inch (51 mm) or 3-inch (76 mm) nominal thickness. 2. For the calculation of the in-plane shear strength of anchor bolts attaching cold-formed steel track of bearing or nonbearing walls of light-frame construction to foundations or foundation stemwalls, the in-plane shear strength in accordance with Sections 17.7.2 and 17.7.3 of ACI 318 need not be computed and 17.10.6.3 shall be deemed to be satisfied provided that all of the following are met:
Allowable in-plane shear strength of exempt anchors, parallel to the edge of concrete, shall be permitted to be determined in accordance with AISI S100 Section J3.3.1.
2.1. The maximum anchor nominal diameter is [5] / 8 inch (16 mm). 2.2. Anchors are embedded into concrete a minimum of 7 inches (178 mm).
2025 CALIFORNIA BUILDING CODE 19-7
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CONCRETE
2.3. Anchors are located a minimum of 1 [3] / 4 inches (45 mm) from the edge of the concrete parallel to the length of the track.
2.4. Anchors are located a minimum of 15 anchor diameters from the edge of the concrete perpendicular to the length of the track. 2.5. The track is 33 to 68 mil (0.84 mm to 1.73 mm) designation thickness. 3. In light-frame construction bearing or nonbearing walls, shear strength of concrete anchors less than or equal to 1 inch (25 mm) in diameter attaching sill plate or track to foundation or foundation stemwalls need not satisfy Sections 17.10.6.3(a) through (c) when the design strength of the anchors is determined in accordance with Section 17.7.2.1(c) of ACI 318.
SECTION 1906—FOOTINGS FOR LIGHT-FRAME CONSTRUCTION
[OSHPD 1R, 2 & 5] Plain concrete footings not permitted by OSHPD.
1906.1 Plain concrete footings. For Group R-3 occupancies and buildings of other occupancies less than two stories above grade plane of light-frame construction, the required thickness of plain concrete footings is permitted to be 6 inches (152 mm), provided that the footing does not extend more than 4 inches (102 mm) on either side of the supported wall.
SECTION 1907—SLABS-ON-GROUND
1907.1 Structural slabs-on-ground. Structural concrete slabs-on-ground shall comply with all applicable provisions of this chapter. Slabs-on-ground shall be considered structural concrete where required by ACI 318 or where designed to transmit either of the following:
- Vertical loads or lateral forces from other parts of the structure to the soil.
- Vertical loads or lateral forces from other parts of the structure to foundations.
CBC § 3.1. Medium relevance — show source text
Allowable in-plane shear strength of exempt anchors, parallel to the edge of concrete, shall be permitted to be determined in accordance with AISI S100 Section J3.3.1.
2.1. The maximum anchor nominal diameter is [5] / 8 inch (16 mm). 2.2. Anchors are embedded into concrete a minimum of 7 inches (178 mm). 2.3. Anchors are located a minimum of 1 [3] / 4 inches (45 mm) from the edge of the concrete parallel to the length of the track.
2.4. Anchors are located a minimum of 15 anchor diameters from the edge of the concrete perpendicular to the length of the track. 2.5. The track is 33 to 68 mil (0.84 mm to 1.73 mm) designation thickness. 3. In light-frame construction bearing or nonbearing walls, shear strength of concrete anchors less than or equal to 1 inch (25 mm) in diameter attaching sill plate or track to foundation or foundation stemwalls need not satisfy Sections 17.10.6.3(a) through (c) when the design strength of the anchors is determined in accordance with Section 17.7.2.1(c) of ACI 318.
SECTION 1906 A — RESERVED
SECTION 1907 A —SLABS-ON-GROUND
1907 A .1 Structural slabs-on-ground. Structural concrete slabs-on-ground shall comply with all applicable provisions of this chapter. Slabs-on-ground shall be considered structural concrete where required by ACI 318 or where designed to transmit either of the following:
- Vertical loads or lateral forces from other parts of the structure to the soil.
- Vertical loads or lateral forces from other parts of the structure to foundations.
2025 CALIFORNIA BUILDING CODE 19A-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CONCRETE
1907 A .2 Nonstructural slabs-on-ground. Nonstructural slabs-on-ground shall be required to comply with Sections 1904 A .2, 1907 A .3 and 1907 A .4. Portions of the nonstructural slabs-on-ground used to resist uplift forces or overturning shall be designed in accordance with accepted engineering practice throughout the entire portion designated as dead load to resist uplift forces or overturning. 1907 A .3 Thickness. The thickness of concrete floor slabs supported directly on the ground shall be not less than 3 [1] / 2 inches (89 mm).
1907 A .4 Vapor retarder. A 6-mil (0.006 inch; 0.15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete floor slab, or other approved equivalent methods or materials shall be used to retard vapor transmission through the floor slab.
Exception: A vapor retarder is not required:
- For detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities.
CBC § 1.1 Medium relevance — show source text
1.1_|||||||||X||X|X|||X|||||||||| |1901.1.2|||||||||X||X|X|||X|||||||||| |1901.1.3|||||||||X||X|X|||X|||||||||| |1901.1.4|||||||||X|||||||||||||||| |1901.1.5|||||||||X|||||||||||||||| |1901.3.1 – 1901.3.4.5|||||||||||X|X|||X|||||||||| |1903.1|||||||||||X|X|||X|||||||||| |1903.3|||||||||||X|X|||X|||||||||| |1903.4|||||||||||X|X|||X|||||||||| |1903.5|||||||||||X|X|||X|||||||||| |1905.1.8||||||||||||||||||||||||| |1905.5|||||||||||X|X|||X|||||||||| |1905.6|||||||||||X|X|||X|||||||||| |1906|||||||||||X|X|||X|||||||||| |1907.4.1||||X||||||||||||||||||||| |1908.1|||||||||||X|X|||X|||||||||| |1909|||||||||X|||||||||||||||| |1910|||||||||||X|X|||X|||||||||| |1911|||||||||||X|X|||X||||||||||
The state agency does not adopt sections identified with 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 19-1
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
19-2 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
19 CONCRETE
User notes:
About this chapter: Chapter 19 provides minimum accepted practices for the design and construction of buildings and structural components using concrete—both plain and reinforced. Chapter 19 relies primarily on the reference to American Concrete Institute (ACI) 318, Building Code Requirements for Structural Concrete. Structural concrete must be designed and constructed to comply with this code and all listed standards. There are also specific provisions addressing slabs-on-ground and shotcrete.
This chapter was extensively reorganized for the 2024 edition. For complete information, see the relocations table in the Preface information of this code.
ICC code development note: Code change proposals to this chapter will be considered by the IBC—Structural Code Development Committee during the
2025 (Group B) Code Development Cycle.
SECTION 1901—GENERAL
1901.1 Scope. The provisions of this chapter shall govern the materials, quality control, design and construction of concrete used in structures.
CBC § 2.1.1 Medium relevance — show source text
24.2.1.1 – Span to depth ratio. Prestressed beam and slab span to depth ratios for continuous prestressed concrete members shall not exceed the following, except when calculations of deflections and vibration effects prove that greater values may be used without adverse effects:
Beams...............................30
One-way slabs..................40
Two-way floor slabs.........40
Two-way roof slabs..........44
These ratios should be decreased for special conditions such as heavy loads and simple spans.
Maximum deflection criteria shall be in accordance with ACI 318 Section 24.2.2.
1909A.1.13 ACI 318, Section 25.2.10. Replace ACI 318 Section 25.2.10 by the following:
25.2.10 – For ties and hoops in columns to be placed with shotcrete, minimum clear spacing shall be 3 in. Shotcrete shall not be applied to spirally tied columns.
1909A.1.14 ACI 318, Section 26.5.2. Modify ACI 318 Section 26.5.2.1 by replacing items (l), (m) and (n) and adding item (q) as follows: (l) Shotcrete surfaces intended to receive subsequent shotcrete placement following an interruption of 30 minutes or more shall be roughened to a full amplitude of approximately [1] / 4 in. before the shotcrete has reached final set. The film of laitance which forms on the surface of the shotcrete shall be removed within approximately 2 hours after application by brushing with a stiff broom. If this film is not removed within 2 hours, it shall be removed by thorough wire brushing or a mechanical method acceptable to the enforcement agency. (m) Before placing additional material onto hardened shotcrete, laitance shall be removed, joints shall be cleaned, and the surface shall be dampened. Construction joints over 8 hours old shall be thoroughly cleaned with air and water prior to receiving shotcrete. (n) In-place fresh concrete that exhibits sags, sloughs, segregation, honeycombing, sand pockets, or other obvious defects shall be removed and replaced. Shotcrete above sags and sloughs shall be removed and replaced while still plastic. (q) Surface preparation: Concrete or masonry to receive shotcrete shall have the entire surface thoroughly cleaned and rough- ened by a mechanical method acceptable to the enforcement agency, and just prior to receiving shotcrete shall be thoroughly cleaned of all debris, dirt and dust. Concrete and masonry shall be brought to a saturated surface-dry (SSD) condition before shotcrete is deposited.
1909A.1.15 ACI 318, Section 26.11.1.2. Modify ACI 318 Section 26.11.1.2 by adding item (e) as follows:
(e) Forms for shotcrete shall be substantial and rigid. Forms shall be built and placed so as to permit the escape of air and rebound. Adequate ground wires, which are to be used as screeds, shall be placed to establish the thickness, surface planes and form of the shotcrete work. All surfaces shall be rodded to these wires.
1909A.1.16 ACI 318, Section 26.12.2.1(a). Replace ACI 318 Section 26.12.2.1(a) by the following:
Frequently asked questions
What minimum thickness and moisture control does the CBC require for slabs‑on‑ground?
The CBC requires a minimum slab thickness of 3 1/2 inches for floor slabs supported directly on the ground and generally requires a 6‑mil polyethylene vapor retarder (with listed exceptions) between the subgrade and slab; see §1907.3 and §1907.4 for the details .
Are there special inspection or testing requirements for shotcrete?
Yes. Shotcrete must conform to ACI 318 and ACI 506 and the CBC requires preconstruction mockup testing, specified compressive strength, and special inspection/testing as described in the shotcrete and special inspection provisions (see §1908 and the referenced special‑inspection sections) file.
Can existing concrete always be used in rehabilitation work?
No. The CBC requires representative coring to establish in‑place strength and prohibits structural use of existing concrete with core strengths below the code minimum (the code calls out a minimum core strength on the order of 1,500 psi and prescribes sampling frequencies) .
More in California Building Code
- Administration & Permits
- Energy Efficiency
- Existing Buildings
- Occupancy Classification & Use
- Hazardous Materials & Occupancies
- Types of Construction
- Fire-Resistance & Fire Safety
- Interior Finishes
- Means of Egress
- Accessibility
- Exterior Walls
- Roofing & Roof Assemblies
- Structural Design
- Special Inspections & Tests
- Foundations & Soils
- Concrete
- Masonry
- Steel
- Wood
- Elevators & Conveying Systems
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