California Code of Regulations, Title 24

Chapter 1 Scope and Administration

Chapter 2 Definitions

Chapter 3 Provisions for All Compliance Methods

Chapter 4 Prescriptive Compliance Method

Chapter 5 Classification of Work

Chapter 6 Repairs

Chapter 7 Alterations - Level 1

Chapter 8 Alterations - Level 2

Chapter 9 Alterations - Level 3

Chapter 10 Change of Occupancy

Chapter 11 Additions

Chapter 12 Historic Buildings

Chapter 13 Relocated or Moved Buildings

Chapter 14 Performance Compliance Methods

Chapter 15 Construction Safeguards

Chapter 16 Referenced Standards

Appendix A Guidelines for the Seismic Retrofit of Existing Buildings

Referenced Standards

Chapter A3 Prescriptive Provisions for Seismic Strengthening of Cripple Walls and Sill Plate Anchorage of Light, Wood-Frame Residential Buildings

Chapter A4 Earthquake Risk Reduction in Wood-Frame Residential Buildings With Soft, Weak or Open Front Walls

Chapter A6 Referenced Standards

History Note Appendix California Existing Building Code

Based on Standard Specification C 90–95 of the ASTM International.
Extracted, with permission, from the
Annual Book of ASTM Standards, copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428

Note: See Appendix Chapter A1, Section A106, California Existing Building Code

This standard covers solid (units with 75 percent or more net area) and hollow load-bearing concrete masonry units made from portland cement, water and mineral aggregates with or without the inclusion of other materials.
Two types of concrete masonry units in each of two grades are covered as follows:
Units designated as Type I shall conform to all requirements of this standard including the moisture content requirements of Table 21–4-A.
Units designated as Type II shall conform to all requirements of this standard except the moisture content requirements of Table 21–4-A.
Concrete masonry units manufactured in accordance with this standard shall conform to two grades as follows:
Units having a weight classification of 85 pcf (1360 kg/m3) or greater, for general use such as in exterior walls below and above grade that may or may not be exposed to moisture penetration or the weather and for interior walls and backup.
Units having a weight classification of less than 85 pcf (1360 kg/m3), for uses limited to above-grade installation in exterior walls with weather-protective coatings and in walls not exposed to the weather.

Materials shall conform to the following applicable standards:

  1. Portland Cement—ASTM C 150 modified as follows:

    Limitation on insoluble residue—1.5 percent maximum.

    Limitation on air content of mortar, Volume percent—22 percent maximum.

    Limitation on loss on ignition—7 percent maximum.

    Limestone with a minimum 85 percent calcium carbonate (CaCO3) content may be added to the cement, provided the requirements of ASTM C 150 as modified above are met.

  2. Blended Cements—ASTM C 595.
  3. Hydrated Lime, Type S—UBC Standard 21-13.
Air-entraining agents, coloring pigments, integral water repellents, finely ground silica, aggregates, and other constituents, shall be previously established as suitable for use in concrete or shall be shown by test or experience to not be detrimental to the durability of the concrete.

At the time of delivery to the work site, the units shall conform to the physical requirements prescribed in Table 21–4–B. The moisture content of Type I concrete masonry units at time of delivery shall conform to the requirements prescribed in Table 21–4-A.

At the time of delivery to the purchaser, the linear shrinkage of Type II units shall not exceed 0.065 percent.

Face-shell (FST) and web (WT) thicknesses shall conform to the requirements listed in Table 21–4-C.
For precision units, no overall dimension (width, height and length) shall differ by more than 1/8 inch (3.2 mm) from the specified standard dimensions.

For particular feature units, dimensions shall be in accordance with the following:

  1. For molded face units, no overall dimension (width, height and length) shall differ by more than 1/8 inch (3.2 mm) from the specified standard dimension. Dimensions of molded features (ribs, scores, hex-shapes, patterns, etc.) shall be within 1/16 inch (1.6 mm) of the specified standard dimensions and shall be within 1/16 inch (1.6 mm) of the specified placement of the unit.
  2. For split-faced units, all non-split overall dimensions (width, height and length) shall differ by no more than 1/8 inch (3.2 mm) from the specified standard dimensions. On faces that are split, overall dimensions will vary. Local suppliers should be consulted to determine dimensional tolerances achievable.
  3. For slumped units, no overall height dimension shall differ by more than 1/8 inch (3.2 mm) from the specified standard dimension. On faces that are slumped, overall dimensions will vary. Local suppliers should be consulted to determine dimension tolerances achievable.

Note: Standard dimensions of units are the manufacturer’s designated dimensions. Nominal dimensions of modular size units, except slumped units, are equal to the standard dimensions plus 3/8 inch (9.5 mm), the thickness of one standard mortar joint. Slumped units are equal to the standard dimensions plus 1/2 inch (13 mm), the thickness of one standard mortar joint. Nominal dimensions of nonmodular size units usually exceed the standard dimensions by 1/8 inch to 1/4 inch (3.2 mm to 6.4 mm).

All units shall be sound and free of cracks or other defects that would interfere with the proper placing of the unit or impair the strength or permanence of the construction. Units may have minor cracks incidental to the usual method of manufacture, or minor chipping resulting from customary methods of handling in shipment and delivery.

Units that are intended to serve as a base for plaster or stucco shall have a sufficiently rough surface to afford a good bond.

Where units are to be used in exposed wall construction, the face or faces that are to be exposed shall be free of chips, cracks or other imperfections when viewed from 20 feet (6100 mm), except that not more than 5 percent of a shipment may have slight cracks or small chips not larger than 1 inch (25.4 mm).

The purchaser or authorized representative shall be accorded proper facilities to inspect and sample the units at the place of manufacture from the lots ready for delivery.

Sample and test units in accordance with ASTM C 140.

Total linear drying shrinkage shall be based on tests of concrete masonry units made with the same materials, concrete mix design, manufacturing process and curing method, conducted in accordance with ASTM C 426 and not more than 24 months prior to delivery.

If the samples tested from a shipment fail to conform to the specified requirements, the manufacturer may sort it, and new specimens shall be selected by the purchaser from the retained lot and tested at the expense of the manufacturer. If the second set of specimens fails to conform to the specified requirements, the entire lot shall be rejected.

TABLE 21–4-A

MOISTURE CONTENT REQUIREMENTS FOR TYPE I UNITS

LINEAR SHRINKAGE, PERCENTMOISTURE CONTENT, MAX. PERCENT OF TOTAL ABSORPTION (Average of 3 Units)
Humidity Conditions at Job site or Point of Use
Humid1Intermediate2Arid3
0.03 or less454035
From 0.03 to 0.045403530
0.045 to 0.065, max.353025
  • 1Average annual relative humidity above 75 percent.
  • 2Average annual relative humidity 50 to 75 percent.
  • 3Average annual relative humidity less than 50 percent.

TABLE 21–4-B

STRENGTH AND ABSORPTION REQUIREMENTS

COMPRESSIVE STRENGTH, MIN, psi (MPa)WATER ABSORPTION, MAX, lb./ft. (kg/m) (Average of 3 Units)
Average Net AreaWeight Classification—Oven-dry Weight of Concrete, lb./ft. (kg/m)
Average of 3 UnitsIndividual UnitLightweight, Less than 105 (1680)Medium Weight, 105 to less than 125 (1680-2000)Normal Weight, 125 (2000) or more
1900 (13.1)1700 (11.7)18 (288)15 (240)13 (208)

TABLE 21–4-C

MINIMUM THICKNESS OF FACE-SHELLS AND WEBS

NOMINAL WIDTH (W) OF UNIT (inches)FACE-SHELL THICKNESS (FST) MIN., (inches)1,4WEB THICKNESS (WT)
Webs1 Min., (inches)Equivalent Web Thickness, Min., In./Lin. Ft.2
× 25.4 for mm× 83 for mm/lin. m
3 and 43/43/415/8
61121/4
811/4121/4
1013/811/821/2
11/43
1211/211/821/2
11/43
  • 1 Average of measurements on three units taken at the thinnest point.
  • 2 Sum of the measured thickness of all webs in the unit, multiplied by 12 (305 when using metric), and divided by the length of the unit. In the case of open-ended units where the open-ended portion is solid grouted, the length of that open-ended portion shall be deducted from the overall length of the unit.
  • 3 This face-shell thickness (FST) is applicable where allowable design load is reduced in proportion to the reduction in thicknesses shown, except that allowable design load on solid-grouted units shall not be reduced.
  • 4 For split-faced units, a maximum of 10 percent of a shipment may have face-shell thicknesses less than those shown, but in no case less than 3/4 inch (19 mm).

See Appendix Chapter 1, Sections A1 06.3.3 and A1 07.2, Uniform Code for Building Conservation
Note: See Appendix Chapter A1, Section A104, California Existing Building Code.

This standard applies when the Uniform Code for Building Conservation (California Existing Building Code) requires in-place testing of the quality of masonry mortar.
The bed joints of the outer wythe of the masonry shall be tested in shear by laterally displacing a single brick relative to the adjacent bricks in the same wythe. The head joint opposite the loaded end of the test brick shall be carefully excavated and cleared. The brick adjacent to the loaded end of the test brick shall be carefully removed by sawing or drilling and excavating to provide space for a hydraulic ram and steel loading blocks.
Steel blocks, the size of the end of the brick, shall be used on each end of the ram to distribute the load to the brick. The blocks shall not contact the mortar joints. The load shall be applied horizontally, in the plane of the wythe, until either a crack can be seen or slip occurs. The strength of the mortar shall be calculated by dividing the load at the first cracking or movement of the test brick by the nominal gross area of the sum of the two bed joints.

See Appendix Chapter 1, Section A1 07.3 and A1 07.4, Uniform Code for Building Conservation
Note: See Appendix Chapter A1, Section A105, A107.3, A107.4 and Table A1-E, California Existing Building Code.

Shear and tension anchors in existing masonry construction shall be tested in accordance with this standard when required by the Uniform Code for Building Conservation (California Existing Building Code).
The test apparatus shall be supported by the masonry wall. The distance between the anchor and the test apparatus support shall not be less than one half the wall thickness for existing anchors and 75 percent of the embedment for new embedded bolts. Existing wall anchors shall be given a pre-load of 300 pounds (1335 N) prior to establishing a datum for recording elongation. The tension test load reported shall be recorded at 1/8 inch (3.2 mm) relative movement of the existing anchor and the adjacent masonry surface. New embedded tension bolts shall be subject to a direct tension load of not less than 2.5 times the design load but not less than 1,500 pounds (6672 N) for five minutes (10 percent deviation).

Bolts embedded in unreinforced masonry walls shall be tested using a torque-calibrated wrench to the following minimum torques:

1/2-inch-diameter (13 mm) bolts—40 foot pounds (54.2 N • m)

5/8-inch-diameter (16 mm) bolts—50 foot pounds (67.8 N • m)

3/4-inch-diameter (19 mm) bolts—60 foot pounds (81.3 N • m)

This section is applicable when it is desired to use tension or shear values for anchors greater than those permitted by Table A-1-E of the Uniform Code for Building Conservation (California Existing Building Code). The direct-tension test procedure set forth in Section 21.702 for existing anchors may be used to determine the allowable tension values for new embedded or through bolts, except that no preload is required. Bolts shall be installed in the same manner and using the same materials as will be used in the actual construction. A minimum of five tests for each bolt size and type shall be performed for each class of masonry in which they are proposed to be used. The allowable tension values for such anchors shall be the lesser of the average ultimate load divided by a factor of safety of 5.0 or the average load of which 1/8 inch (3.2 mm) elongation occurs for each size and type of bolt and class of masonry.

Shear bolts may be similarly prequalified. The test procedure shall comply with ASTM E 488-90 or another approved procedure.

The allowable values determined in this manner may exceed those set forth in Table A-1-E of the Uniform Code for Building Conservation (California Existing Building Code).

Results of all tests shall be reported. The report shall include the test results as related to anchor size and type, orientation of loading, details of the anchor installation and embedment, wall thickness, and joist orientation.

See Appendix Chapter 1, Section A1 06.3.3.2, Uniform Code for Building Conservation
Note: See Appendix Chapter A1, Section A103 and A106.3.3.9, California Existing Building Code.

Pointing of deteriorated mortar joints when required by the Uniform Code for Building Conservation (California Existing Building Code) shall be in accordance with this standard.
The old or deteriorated mortar joint shall be cut out, by means of a toothing chisel or nonimpact power tool, to a uniform depth of 3/4 inch (19 mm) until sound mortar is reached. Care shall be taken not to damage the brick edges. After cutting is complete, all loose material shall be removed with a brush, air or water stream.
The mortar mix shall be Type N or Type S proportioned as required by the construction specifications. The pointing mortar shall be pre-hydrated by first thoroughly mixing all ingredients dry and then mixing again, adding only enough water to produce a damp unworkable mix which will retain its form when pressed into a ball. The mortar shall be kept in a damp condition for one and one-half hours; then sufficient water shall be added to bring it to a consistency that is somewhat drier than conventional masonry mortar.
The joint into which the mortar is to be packed shall be damp but without freestanding water. The mortar shall be tightly packed into the joint in layers not exceeding 1/4 inch (6.4 mm) in depth until it is filled; then it shall be tooled to a smooth surface to match the original profile.

Based on Standard Specification C 207–91 (Reapproved 1992) of the ASTM International.
Extracted, with permission, from the
Annual Book of ASTM Standards, copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428

See Section 2102.2, Item 3,Uniform Building Code
Note: See Referenced Standard UBC 21-4

This standard covers four types of hydrated lime. Types N and S are suitable for use in mortar, in the scratch and brown coats of cement plaster, for stucco, and for addition to portland-cement concrete. Types NA and SA are air-entrained hydrated limes that are suitable for use in any of the above uses where the inherent properties of lime and air entrainment are desired. The four types of lime sold under this specification shall be designated as follows:

Type N—Normal hydrated lime for masonry purposes.

Type S—Special hydrated lime for masonry purposes.

Type NA—Normal air-entraining hydrated lime for masonry purposes.

Type SA—Special air-entraining hydrated lime for masonry purposes.

Note: Type S, special hydrated lime, and Type SA, special air-entraining hydrated lime, are differentiated from Type N, normal hydrated lime, and Type NA, normal airentraining hydrated lime, principally by their ability to develop high, early plasticity and higher water retentivity and by a limitation on their unhydrated oxide content.

HYDRATED LIME. The hydrated lime covered by Type N or S in this standard shall contain no additives for the purpose of entraining air. The air content of cement-lime mortars made with Type N or S shall not exceed 7 percent. Types NA and SA shall contain an air-entraining additive as specified by Section 21.1305. The air content of cement-lime mortars made with Type NA or SA shall have a minimum of 7 percent and a maximum of 14 percent.
Types NA and SA hydrated lime covered by this standard shall contain additives for the purpose of entraining air.
Where required, the nature, amount and identity of the airentraining agent used and of any processing addition that may have been used shall be provided, as well as test data showing compliance of such air-entraining addition.
Hydrated lime for masonry purposes shall conform to the requirements as to chemical composition set forth in Table 21–13–A.

The four types of hydrated lime for masonry purposes shall conform to one of the following requirements:

  1. The residue retained on a No. 30 (600 μm) sieve shall not be more than 0.5 percent, or
  2. If the residue retained on a No. 30 (600 μm) sieve is over 0.5 percent, the lime shall show no pops and pits when tested.
The putty made from Type S, special hydrate, or Type SA, special air-entraining hydrate, shall have a plasticity figure of not less than 200 within 30 minutes after mixing with water, when tested.

Hydrated lime mortar made with Type N, normal hydrated lime, or Type NA, normal air-entraining hydrated lime, after suction for 60 seconds, shall have a water-retention value of not less than 75 percent when tested in a standard mortar made from the dry hydrate or from putty made from the hydrate which has been soaked for a period of 16 to 24 hours.

Hydrated lime mortar made with Type S, special hydrated lime, or Type SA, special air-entraining hydrated lime, after suction for 60 seconds, shall have a water-retention value of not less than 85 percent when tested in a standard mortar made from the dry hydrate.

When Type NA or SA air-entraining hydrated lime is delivered in packages, the type under this standard and the words “air-entraining” shall be plainly indicated thereon or, in case of bulk shipments, so indicated on shipping notices.

Every 90 days, each lime producer shall retain an approved agency to obtain a random sample from a local point of supply in the market area served by the producer.

The agency shall test the lime for compliance with the physical requirements of Sections 21.1306, 21.1307 and 21.1308.

Upon request of the building official, the producer shall furnish (at no cost) test results to the building official, architect, structural engineer, general contractor and masonry contractor.

Standard specifications for steel sheet, zinc-coated (galvanized) or zinc-iron alloy-coated (galvannealed) by the hot-dip process.

TABLE 21-13-A—CHEMICAL REQUIREMENTS
HYDRATE TYPES
NNASSA
Calcium and magnesium oxides (nonvolatile basis), min. percent95959595
Carbon dioxide (as-received basis), max. percent
  If sample is taken at place of manufacture5555
  If sample is taken at any other place7777
Unhydrated oxides (as-received basis), max. percent--88
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