Section 8-812 — GLASS AND GLAZING — 2025 California Historical Building Code (Title 24, Part 8)

8-812.1 Glazing subject to human impact. Historical glazing material located in areas subject to human impact may be approved subject to the concurrence of the enforcing agency when alternative protective measures are provided. These measures may include, but not be limited to, additional glazing panels, protective film, protective guards or systems, and devices or signs which would provide adequate public safety.

8-812.2 Glazing in fire-rated systems. See Section 8-402.3.

TABLE8-8A—STRENGTH VALUES FOR EXISTING MATERIALS

EXISTING MATERIALS OR CONFIGURATIONS OF MATERIALS1	STRENGTH LEVEL CAPACITY x14.594 for N/m
1. Horizontal diaphragms2 1.1. Roofs with straight sheathing and roofing applied directly to the sheathing 1.2. Roofs with diagonal sheathing and roofing applied directly to the sheathing 1.3. Floors with straight tongue-and-groove sheathing 1.4. Floors with straight sheathing and finished wood flooring with board edges offset or perpendicular 1.5. Floors with diagonal sheathing and finished	300 lbs per foot for seismic shear 750 lbs per foot for seismic shear 300 lbs per foot for seismic shear 1,500 lbs per foot for seismic shear 1,800 lbs per foot for seismic shear
2. Crosswalls2,3 2.1. Plaster on wood or metal lath 2.2. Plaster on gypsum lath 2.3. Gypsum wallboard, unblocked edges 2.4. Gypsum wallboard, blocked edges	Per side: 600 lbs per foot for seismic shear 550 lbs per foot for seismic shear 200 lbs per foot for seismic shear 400 lbs per foot for seismic shear
3. Existing footings, wood framing, structural steel and reinforcing steel 3.1. Plain concrete footings 3.2. Douglas fir wood 3.3. Reinforcing steel 3.4. Structural steel	f ′c = 1,500 psi (10.34 MPa) unless otherwise shown by tests3 Allowable stress same as D.F. No. 13 _ft _= 40,000 lbs per square inch (124.1 N/mm2) maximum ft= 33,000 lbs per square inch (137.9 N/mm2) maximum
1. Material must be sound and in good condition. 2. Shear values of these materials may be combined, except the total combined value shall not exceed 900 pounds per foot (13,140 N/m). 3. Stresses given may be increased for combinations of loads as specified in the regular code.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

ARCHAIC MATERIALS AND METHODS OF CONSTRUCTION

TABLE 8-8B—STRENGTH VALUES OF NEW MATERIALS USED IN CONNECTION WITH EXISTING CONSTRUCTION

NEW MATERIALS OR CONFIGURATIONS OF MATERIALS	STRENGTH LEVEL CAPACITY1
1. Horizontal diaphragms2 1.1. 15/32 inch minimum plywood sheathing fastened directly over existing straight sheathing with edges of plywood located on center of individual sheathing boards and fastened with minimum #8x 11/4 inch wood screws or nails with helical threads 0.13 inch min. diameter and 11/4 inch min. length at 4 inch centers all panel edges and 12 inch centers each way in field 1.2. Same plywood and attachments as 1.1 fastened directly over existing diago- nal sheathing 1.3. 3/8 inch plywood sheathing fastened directly over existing straight or diagonal sheathing with ends and edges on centers of individual sheathing boards and fastened with #6 wood screws or nails with helical threads 0.13 inch min. diameter and 11/4 inch min. length at 6 inch centers tall panel edges and 12 inch centers each way in field	1,500 lbs per foot 1,800 lbs per foot 900 lbs per foot
2. Shear walls: Plywood sheathing applied directly over wood studs. No value shall be given to plywood applied over existing plaster or wood sheathing	100 percent of the value specified in the regular code for shear walls
3. Crosswalls: (special procedure only) 3.1. Plywood sheathing applied directly over wood studs. No value shall be given to plywood applied over existing plaster or wood sheathing 3.2. Drywall or plaster applied directly over wood studs 3.3. Drywall or plaster applied to sheathing over existing wood studs	133 percent of the value specified in the regular code for shear walls 100 percent of the value specified in the regular code 50 percent of the value specified in the regular code
4. Tension bolts a. Bolts extending entirely through unreinforced masonry walls secured with bearing plates on far side of a three-wythe minimum wall with at least 30 square inches (19 350 mm2) of area4,5 b. All thread rod extending to the exterior face of the wall installed in adhesive9	5,400 lbs (24 010 N) per bolt6 2,700 lbs (12 009 N) per bolt for two-wythe walls6 3,600 lbs (16 014 N) per bolt
5. Shear bolts Bolts embedded a minimum of 8 inches (203 mm) into unreinforced masonry walls and centered in a 21/2-inch-diameter (63.5 mm) hole filled with dry-pack or nonshrink grout. Through bolts with first 8 inches (203 mm) as noted above and embedded all thread rod as noted in Item 4.b5,7,9	1/2 inch (12.7 mm) diameter = 1,050 lbs (4671 N)6 5/8 inch (15.9 mm) diameter = 1,500 lbs (6672 N)6 3/4 inch (19 mm) diameter = 2,250 lbs (10 008 N)6
6. Infilled walls Reinforced masonry infilled openings in existing unreinforced masonry walls. Provide keys or dowels to match reinforcing.	Same as values specified for unreinforced masonry walls
7. Reinforced masonry Masonry piers and walls reinforced per the regular code	Same as values specified in the regular code8
8. Reinforced concrete Concrete footings, walls and piers reinforced as specified in the regular code and designed for tributary loads	Same as values specified in the regular code8
1. Values are for strength level loads as defined in regular code standards. 2. Values may be adjusted for other fasteners when approved by the enforcing authority. 3. In addition to existing sheathing value. 4. Bolts to be1/2-inch (12.7 mm) minimum diameter. 5. Other bolt sizes, values and installation methods may be used provided a testing program is conducted in accordance with regular code standards. Bolt spacing shall not exceed 6 feet (1830 mm) on center and shall not be less than 12 inches (305 mm) on center. 6. Other masonry based on tests or other substantiated data. 7. Embedded bolts to be tested as specified in regular code standards. 8. Stresses given may be increased for combinations of loads as specified in the regular code. 9. Adhesives shall be approved by the enforcing agency and installed in accordance with the manufacturer’s recommendations. All drilling dust shall be removed from drilled holes prior to installation.

18 2025 CALIFORNIA HISTORICAL BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.