Chapter 21 — MASONRY

(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user.

See Chapter 1 for state agency authority and building applications.)

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.

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

100735044

244 2019 CALIFORNIA BUILDING CODE Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

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CHAPTER 21

MASONRY

User notes:

About this chapter: Chapter 21 establishes minimum requirements for masonry construction. The provisions address: material specifications and test methods; types of wall construction; criteria for engineered and empirical designs; and required details of construction, including the execution of construction. The provisions provide a framework for applying applicable standards to the design and construction of masonry structures. Masonry design methodologies including allowable stress design, strength design and empirical design are covered by the provi- sions of this chapter. Also addressed are masonry fireplaces and chimneys, masonry heaters and glass unit masonry.

Code development reminder: Code change proposals to this chapter will be considered by the IBC—Structural Code Development Commit- tee during the 2019 (Group B) Code Development Cycle. See explanation on page ix.

Masonry shall comply with the provisions of TMS 402, TMS 403 or TMS 404 as well as applicable requirements of this chapter. [OSHPD 1R, 2 & 5] TMS 403 Not permitted by OSHPD.

2101.2.1 Masonry veneer. Masonry veneer shall comply with the provisions of Chapter 14.

2101.2.2 Prohibition. [OSHPD 1R, 2 & 5] The following design methods, systems, and materials are not permitted by OSHPD:

1. Unreinforced masonry.

2. Autoclaved Aerated Concrete (AAC) Masonry.

3. Empirical design of masonry and prescriptive design of masonry partition walls.

4. Adobe construction.

5. Ordinary reinforced masonry shear walls.

6. Intermediate reinforced masonry shear walls.

7. Prestressed masonry shear walls.

8. Direct design of masonry.

The special inspection of masonry shall be as defined in Chapter 17, or an itemized testing and inspection program shall be provided that meets or exceeds the requirements of Chapter 17.

Air-entraining substances shall not be used in grout unless tests are conducted to determine compliance with the requirements of this code.

These tests are to establish whether the masonry components meet the specified compo- nent strengths. At the beginning of all masonry work, at least one test sample of the mortar shall be taken on three successive working days and at least at one-week intervals thereafter. Samples of grout shall be taken for each mix design, each day grout is placed, and not less than every 5,000 square feet of masonry wall area. They shall meet the minimum strength requirement given in ASTM C270 Table 1 and ASTM C476/TMS 602 Section 2.2 for mortar and grout respectively. Additional samples shall be taken when- ever any change in materials or job conditions occur, as determined by the building official. When the prism test method is used during construction, the tests in this section are not required.

Test specimens for mortar and grout shall be made as set forth in ASTM C1586 and ASTM C1019 .

Exceptions:

1. [DSA-SS & OSHPD 1 & 4] For nonbearing non- shear masonry walls not exceeding total wall height of 12 feet above top of foundation, mortar tests shall be permitted to be limited to those at the beginning of masonry work for each mix design.

2. [DSA-SS] Mortar sampling and testing shall be as follows: At the beginning of all masonry work, mor- tar test samples shall be taken on three successive working days and at least at one-week intervals thereafter. Where mortar is based on a proportion specification, mortar shall be sampled and tested during construction in accordance with ASTM C780 Annex 4 and 5 to verify the proportions specified in ASTM C270, Table 2. Where mortar is based on a property specification, mortar shall be laboratory prepared and tested prior to construction in accor- dance with ASTM C780 to verify the properties specified in ASTM C270, Table 1 and field sampled and tested during construction in accordance with ASTM C780 to verify the proportions with the labo- ratory tests. Mortar sampling and testing is not required for preblended mortars in conformance with ASTM C270 with a valid evaluation report.

Not less than two cores shall be taken from each building for each 5,000 square feet (465 m ² ) of the masonry wall area or fraction thereof. The approved agency shall perform or observe the coring of the masonry walls and sample locations shall be subject to approval of the registered design professional.

Core samples shall comply with the following:

1. Cored no sooner than 7 days after grouting of the selected area;

2. Be a minimum of 3 ³ /4 inches in nominal diameter; and

consolidated so as to completely fill all voids and embed all reinforcing steel. Horizontal reinforce- ment shall be fully embedded in grout in an unin- terrupted pour.

Exception: The 4 feet maximum wall con- struction may be increased to 5 feet 4 inches for 10-inch nominal and larger hollow-unit masonry.

2104A.1.3.1.2.3 High-lift grouted construction. Where high-lift grouting is used, the method shall be approved by the enforcement agency. Clea- nout openings shall be provided in every cell at the bottom of each pour of grout. Alternatively, if the course at the bottom of the pour is con- structed entirely of inverted double open-end bond beam units, cleanout openings need only be provided for access to every reinforced cell at the bottom of each pour of grout. The cleanouts shall be sealed before grouting. An approved admix- ture that reduces early water loss and produces an expansive action shall be used in the grout.

Modify by adding Section 8.3.8, as fol- lows:

8.3.8 - Walls and Piers.

Thickness of Walls. For thickness limitations of walls as specified in this chapter, nominal thickness shall be used. Stresses shall be determined on the basis of the net thick- ness of the masonry, with consideration for reduction, such as raked joints.

The thickness of masonry walls shall be designed so that allowable maximum stresses specified in this chapter are not exceeded. Also, no masonry wall shall exceed the height or length-to-thickness ratio or the minimum thick- ness as specified in this chapter and as set forth in Table 2107A.4.

Piers. Every pier or wall section which width is less than three times its thickness shall be designed and constructed as required for columns if such pier is a structural mem- ber. Every pier or wall section which width is between three and five times its thickness or less than one half the height of adjacent openings shall have all horizontal steel in the form of ties except that in walls 12 inches (305 mm) or less in thickness such steel may be in the form of hair- pins.

TABLE 2107A.4 MINIMUM THICKNESS OF MASONRY WALLS ^{1, 2}

2. Minimum reinforcement for masonry columns. The spacing of column ties shall be as follows: not greater than 8 bar diameters, 24 tie diame- ters, or one half the least dimension of the col- umn for the full column height. Ties shall be at least ³ /8 inch (10 mm) diameter and shall be embedded in grout. Top tie shall be within 2 inches (51 mm) of the top of the column or of the bottom of the horizontal bar in the supported beam.

3. Lateral support. Lateral support of masonry may be provided by cross walls, columns, pilasters, counterforts or buttresses where spanning hori- zontally or by floors, beams, girts or roofs where spanning vertically. Where walls are supported laterally by vertical elements, the stiffness of each vertical element shall exceed that of the tributary area of the wall.

4. Anchor bolts. Bent bar anchor bolts shall not be allowed. The maximum size anchor shall be ¹ /2- inch (13 mm) diameter for 6-inch (152 mm) nom- inal masonry, ³ /4-inch (19 mm) diameter for 8- inch (203 mm) nominal masonry, ⁷ /8-inch (22 mm) diameter for 10-inch (254 mm) nominal masonry, and 1-inch (25mm) diameter for 12- inch (304.8 mm) nominal masonry.

Modify TMS402, Section 8.3.4.4 by the following:

All reinforced masonry components that are subjected to in-plane forces shall have a maximum reinforcement ratio, ρ max, not greater than that computed by Equation 8-20.