CRSC · California Referenced Standards Code
What are the physical dimensions and components of the SFM 12-71-1 test duct and apparatus
The CRSC SFM **§ 12-71-100** prescribes a fixed test duct and apparatus: a reinforced galvanized duct **21 in. square by 13½ ft long**, a metal frame for a **20×20 in.** filter, two **1‑in** burner outlets about **18 in.** from the filter, air velocity set to **≈200 ft/min**, and a defined photoelectric smoke‑measurement method and classification thresholds (Class 1 / Class 2) used to judge filter combustibility and smoke production.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The State Fire Marshal test apparatus for air filters is defined in § 12-71-100 and requires a rigid, galvanized metal test duct of fixed cross-section and length, a metal filter frame sized for a nominal 20 × 20 inch filter, observation doors with mica windows, a pair of gas-burner outlets, and instrumentation/arrangements to produce and measure a specified air velocity and smoke signal. These elements, plus the test timing and smoke-measurement method that produce the classification criteria (Class 1 / Class 2), are set out in § 12-71-100.
The apparatus must be a reinforced galvanized duct 21 inches square and 13½ feet long with a filter frame for a 20 × 20 inch filter, two 1‑inch burner outlets about 18 inches from the filter base, and an air velocity adjusted to ≈200 ft/min at the discharge end — all as required by § 12-71-100.
Requirements in detail
All quoted dimensions and component descriptions below are grounded in § 12-71-100 of the CRSC.
Duct geometry and construction
- Duct cross-section: 21 inches square (specified in the standard). § 12-71-100(a).1.
- Duct length: 13½ feet (4114 mm as shown in the text). § 12-71-100(a).1.
- Material/rigidity: Made of mild-steel (“M.S.”) gage galvanized sheet metal and reinforced with angle irons. § 12-71-100(a).1.
Filter holder and access
- Filter frame: Metal frame located near mid-length to receive one 20 × 20 inch (nominal) filter unit. § 12-71-100(a).2.
- Access doors: Two tight‑fitting doors placed to permit access to the filter frame; each door has a mica window to observe both faces and downstream conditions. § 12-71-100(a).2.
Burner and flame sources
- Burner outlets: Two 1‑inch (25 mm) pipe elbows used as burner outlets, positioned about 18 inches (457 mm) from the base of the test filter; adjusted to produce yellow, wavering flames. § 12-71-100(a).3.
- Fuel consumption (approx.): Burners consume approximately 4 cubic feet of gas per minute (note text also references energy content). § 12-71-100(a).3.
Airflow, instrumentation and smoke measurement
- Air velocity (operating): With the filter in place, the air velocity is adjusted to approximately 200 linear feet per minute, measured at the discharge end of the duct with an Alnor Velometer Anemometer. § 12-71-100(a).4.
- Photoelectric cell & light source location: Photoelectric cell mounted a few inches below and about 12 inches (305 mm) inside the discharge end of the duct; light source mounted 1 inch (25 mm) above the duct directly above the cell. Readings taken on a microammeter at specified intervals. § 12-71-100(b).2.
- Timing & data collection: Readings recorded every 5 seconds for the first minute and every 10 seconds for the next two minutes; the plotted curve area (under microammeter vs. time) is used as the smoke-density measure. § 12-71-100(b).2–3.
Classification thresholds and adhesive-coating rule
- Class 1: No flames or sparks downstream and area under smoke curve < 1.5 square inches (967 mm²). § 12-71-100(c).1.
- Class 2: May burn moderately or emit moderate smoke but area under smoke curve ≤ 6.0 square inches (3871 mm²) and must not project flames/sparks that would ignite material beyond the duct discharge during the test. § 12-71-100(c).2.
- Adhesive coatings: Liquid adhesives used on filters must have a flash point ≥ 325°F (163°C) Cleveland open cup. § 12-71-100(d).
Decision‑relevant dimensions & values (quick reference table)
| Item | Required value / description | Code Reference |
|---|---|---|
| Duct cross-section | 21 inches square | § 12-71-100(a).1 |
| Duct length | 13½ feet (4114 mm shown) | § 12-71-100(a).1 |
| Filter size (frame) | 20 × 20 inches (nominal) | § 12-71-100(a).2 |
| Access doors/windows | Two tight-fitting doors with mica windows | § 12-71-100(a).2 |
| Burner outlet pipe size | 1‑inch pipe elbows | § 12-71-100(a).3 |
| Burner outlet location | ~18 inches from filter base | § 12-71-100(a).3 |
| Burner gas consumption | ≈4 cu ft/min (approx.) | § 12-71-100(a).3 |
| Test air velocity | ≈200 ft/min at duct discharge | § 12-71-100(a).4 |
| Photoelectric cell location | A few inches below and 12 in inside discharge end | § 12-71-100(b).2 |
| Light source location | 1 inch above duct directly above cell | § 12-71-100(b).2 |
| Flame application duration | 3 minutes | § 12-71-100(b).1 |
| Class 1 threshold | Area < 1.5 in² (and no flame/sparks downstream) | § 12-71-100(c).1 |
| Class 2 threshold | Area ≤ 6.0 in² (and limited burning/smoke) | § 12-71-100(c).2 |
| Adhesive flash point | ≥ 325°F (163°C) Cleveland open cup | § 12-71-100(d) |
Exceptions & special cases
- The standard text does not present alternate duct geometry or burner sizes — the apparatus is prescriptive. Any departure from the specified geometry or instrumentation is not described in § 12-71-100 and therefore would not meet the standard unless an approved equivalent is documented elsewhere. § 12-71-100 only defines the described apparatus and method.
- Adhesive-coated filters are permitted only if the adhesive meets the flash-point requirement in § 12-71-100(d); no lower flash-point adhesives are allowed by this standard.
Common mistakes
- Measuring air velocity at the wrong location. The code requires velocity to be measured at the discharge end of the duct (Alnor Velometer Anemometer). § 12-71-100(a).4.
- Misplacing burners. The burner outlets must be about 18 inches from the base of the test filter; putting them significantly closer or farther will change flame exposure. § 12-71-100(a).3.
- Confusing nominal filter size vs. actual filter face dimensions; the standard explicitly calls out a nominal 20 × 20 inch filter for the frame. § 12-71-100(a).2.
- Misreading the converted metric numbers in the published file: the inch dimensions in the text are the controlling values in the standard; if metric conversions in the document look garbled, rely on the inch figures that the section specifies. § 12-71-100(a).1.
Worked example — concrete scenario
Scenario: A test laboratory sets up the SFM apparatus exactly as specified and runs a single clean (unused) filter test.
- Build duct: fabricate a galvanized sheet-metal duct, 21 in. square cross-section and 13½ ft long, reinforced with angle irons. Install metal filter frame mid-length for a 20 × 20 in. filter. (See § 12-71-100(a).1–2.)
- Install burners: place two 1‑inch pipe‑elbow burners 18 in. downstream of the filter base and set fuel flow to about 4 cu ft/min so flames are yellow/wavering. (See § 12-71-100(a).3.)
- Adjust blower: with the filter installed, adjust blower so the Alnor Velometer reads ≈200 ft/min at the discharge end. (See § 12-71-100(a).4.)
- Run test: apply flames for 3 minutes, watch both faces through mica windows, and record photoelectric microammeter readings (every 5 s for first minute, then every 10 s). (See § 12-71-100(b).1–2.)
- Evaluate smoke area: plot the microammeter difference vs. time, measure area under the curve. If area = 1.2 in² and no flames/sparks traveled downstream, classify Class 1 (area < 1.5 in²). If area = 4.0 in² with only moderate combustion and no projecting flames beyond the discharge, classify Class 2 (area ≤ 6.0 in²). (See § 12-71-100(b).3 and § 12-71-100(c).)
Related provisions
- § 12-71-100 (a) — Test apparatus (duct, burners, filter frame, doors/windows).
- § 12-71-100 (b) — Test method (flame application time, smoke measurement technique).
- § 12-71-100 (c) — Classification criteria (Class 1 and Class 2 thresholds).
- § 12-71-100 (d) — Adhesive‑coating flash-point requirement.
Code references
Grounded in the retrieved California Referenced Standards Code — click a citation to read the verbatim passage:
CRSC § 436.5. High relevance — show source text
DEPARTMENT OF HEALTH SERVICES
Authority: Sections 102, 208 and 25811.
Reference: Sections 102, 208 and 436.5.
ALL HEALING ARTS X-RAY INSTALLATIONS
Sec. 12-31C-101. All radiation shielding barriers in rooms and enclosures housing radiation machines shall comply with the mandatory standards and appendices in Report No. 35, “Dental X-RAY Protection”; Report 49, “Structural Shielding Design and Evaluation for Medical use of X-rays and Gamma Rays of Energies up to 10 MeV”; and Report No. 51, “Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities.” Published by the National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Bethesda, Maryland 20814.
2025 CALIFORNIA REFERENCED STANDARDS CODE 105
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106 2025 CALIFORNIA REFERENCED STANDARDS CODE
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12-71 AIR FILTERS
STANDARD 12-71-1
STATE FIRE MARSHAL
DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS
Sec. 12-71-100.
(a) Test apparatus.
- The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
- One end of the duct is tapered to the discharge of a variable-speed blower and the other end is open to discharge. A metal filter frame is provided near the middle of the length of the duct to receive one 20 by 20 inches (508 mm by 508 mm) (nominal) filter unit. Two tightfitting doors, located to permit access to the filter frame, are each provided with a mica window to permit observation of both faces of the filter and conditions in the duct downstream from the filter.
- Two 1-inch (25 mm) pipe elbows, about 18 inches (457 mm) from the base of the test filter, form gas burner outlets adjusted to provide yellow, wavering flames. The burners consume approximately 4 cubic feet (approximately 1,000 Btu/cubic feet) of gas per minute.
- With the filter in place the air velocity is adjusted to approximately 200 linear feet per minute as measured at the discharge end of the duct by an Alnor Velometer Anemometer.
(b) Test method.
- Filters are tested clean, that is, unused. The flames are applied for 3 minutes during which time observations are made of both faces of the filter as to the downstream travel of flame or sparks and the density, duration and character of the products of combustion.
CRSC § 12-71 High relevance — show source text
STATE FIRE MARSHAL
DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS
Sec. 12-71-100.
(a) Test apparatus.
- The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
- One end of the duct is tapered to the discharge of a variable-speed blower and the other end is open to discharge. A metal filter frame is provided near the middle of the length of the duct to receive one 20 by 20 inches (508 mm by 508 mm) (nominal) filter unit. Two tightfitting doors, located to permit access to the filter frame, are each provided with a mica window to permit observation of both faces of the filter and conditions in the duct downstream from the filter.
- Two 1-inch (25 mm) pipe elbows, about 18 inches (457 mm) from the base of the test filter, form gas burner outlets adjusted to provide yellow, wavering flames. The burners consume approximately 4 cubic feet (approximately 1,000 Btu/cubic feet) of gas per minute.
- With the filter in place the air velocity is adjusted to approximately 200 linear feet per minute as measured at the discharge end of the duct by an Alnor Velometer Anemometer.
(b) Test method.
Filters are tested clean, that is, unused. The flames are applied for 3 minutes during which time observations are made of both faces of the filter as to the downstream travel of flame or sparks and the density, duration and character of the products of combustion.
Smoke density is measured as the drop in light intensity on a microammeter by means of photoelectric cell mounted a few inches below and about 12 inches (305 mm) inside the discharge end of the duct. The light source, stabilized for light intensity, is mounted 1 inch (25 mm) above the duct directly above the photoelectric cell. The microammeter readings are recorded every 5 seconds for the first minute and every 10 seconds for the next 2 minutes.
The differences between these readings and the readings taken before the test are plotted against time (the scale being 40 μA and 40 seconds to the inch) with the resulting area under the curve being measured by use of a planimeter or calculated mathematically. This area is a measure of the smoke density produced during the test.
(c) Classification. As a result of the tests, air filter units are classified as Class 1 or 2 as indicated below:
- Class 1 air filter units are those which, when clean, do not produce flames or sparks when attacked by flame and which develop areas under the smoke density curves that are less than 1.5 square inches (967 mm [2] ).
- Class 2 air filter units are those which, when clean, burn moderately when attacked by flame or emit moderate amounts of smoke or both. These units, although they may be consumed to some extent, do not project flames or extensive sparks that would ignite adjacent combustible materials beyond the discharge end of the duct during the test and do not develop areas under the smoke density curves that are more than 6.0 square inches (3871 mm [2] ).
(d) Adhesive coatings. Liquid-adhesive coatings used on filters shall have a flash point of 325°F (163°C) Cleveland open cup tester, or higher.
CRSC § 12-16 High relevance — show source text
CALIFORNIA STANDARD FOR RESIDENTIAL EXCESS FLOW ACTUATED AUTOMATIC GAS SHUTOFF VALVES (SEE CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-2
DIVISION OF THE STATE ARCHITECT
Authority: Sections 19200–19204, Health and Safety Code. Reference: Sections 19201.5 and 19202, Health and Safety Code.
DIVISION 1—CONSTRUCTION
SCOPE
Sec. 12-16-201. The American Society for Testing and Materials (ASTM) F2138-12(2017) Standard Specification for Excess Flow Valves for Natural Gas Service, and the American National Standards Institute (ANSI) Z21.93-2017/CSA 6.30-2017 Excess Flow Valves for Natural and LP Gas with Pressure up to 5 psig, shall be the applicable standards used by the Division of the State Architect for certification of these devices.
Sec. 12-16-201.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).
2025 CALIFORNIA REFERENCED STANDARDS CODE 103
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104 2025 CALIFORNIA REFERENCED STANDARDS CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
12-31C RADIATION SHIELDING STANDARDS
STANDARD 12-31C-1
DEPARTMENT OF HEALTH SERVICES
Authority: Sections 102, 208 and 25811.
Reference: Sections 102, 208 and 436.5.
ALL HEALING ARTS X-RAY INSTALLATIONS
Sec. 12-31C-101. All radiation shielding barriers in rooms and enclosures housing radiation machines shall comply with the mandatory standards and appendices in Report No. 35, “Dental X-RAY Protection”; Report 49, “Structural Shielding Design and Evaluation for Medical use of X-rays and Gamma Rays of Energies up to 10 MeV”; and Report No. 51, “Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities.” Published by the National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Bethesda, Maryland 20814.
2025 CALIFORNIA REFERENCED STANDARDS CODE 105
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106 2025 CALIFORNIA REFERENCED STANDARDS CODE
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12-71 AIR FILTERS
STANDARD 12-71-1
STATE FIRE MARSHAL
DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS
Sec. 12-71-100.
(a) Test apparatus.
- The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
CRSC § 12.7 High relevance — show source text
Columns shall consist of rolled or built-up wide_ flange sections or noncomposite built-up box or HSS with a minimum wall thickness of [3] / 4 inch (19 mm), or satisfy the requirements of width-to-thickness ratios of highly ductile members in AISC 341. 2. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 3. For SMF and IMF systems, on the sideplate standard or configuration A the U-shaped cover plates shall be used with the k dimension extension. The k dimension extension length is defined as beam depth d b /6, rounded to the nearest [1] / 2 inch (12.7 mm).
4. The hinge-to-hinge span to beam depth, L h /d, shall be greater than or equal to 4.5. 5. The width-to-thickness ratios for beam flanges shall not be less than 3.5. Exception: For width-to-thickness ratios less than 3.5 the C pr shall be calculated in accordance with that for welded side- plate connections but in no case shall the width-to-thickness ratio be less than 3.0. 6. The minimum bolt-to-bolt spacing shall not be less than 3 bolt diameters. 7. The extension of the side plates beyond the face of the column shall be within the range of 0.65d to 1.5d. 8. The gap-to-side plate thickness ratio shall range from 2.1 to 2.3.
Exception: The gap-to-side plate thickness ratio shall be permitted to be modified for moment connections with unequal beam sizes on opposite sides of the column or when orthogonal beams acting as drag connections frame into the side plate. 9. Demand Critical fillet welds {2}, {5}, {5a} and {8} shall have Magnetic Particle Testing (MT) in accordance with AWS D1.1 for procedure, technique and acceptance. Inspect the beginning and end of these welds for a 6-inch (152 mm) length, plus any location along the length of the weld where a start and restart is visually noted for a distance of 6 inches (152 mm) on either side of the start/stop location. 10. The connection specific factor to account for peak connection strength, C pr , shall be between 1.15 and 1.35. Calculations shall be submitted to OSHPD for review and approval. 11. For in-plane collectors transferring axial loads into the sideplate connection, coordination between sideplate and the regis- tered design professional in responsible charge will be required to confirm the collector connection is sufficient to transfer _the load into the moment frame system.
CRSC § 1-3 High relevance — show source text
1-3/4”
Drill 14 ea. 20” Min. − 22” Max. 9/16” Dia. Holes
Wall
3”
1” Min.
3” 3Col2 Col3 ” 3” 3” 3” 3” Col5 Col6 1” Min.
1-3/4”Col8 3” 3
1” Min.3” 3
1” Min.3” 3
1” Min.6” 5/8” 11 6” 5/8” ea.
Dia.
3ea.
Dia.
3ea.
Dia.
3Section F-F Tie Bar Connection 1/4” x 6” x 20” Long Copper (two per phase and one per neutral required) (customer supplied)
Detail D Spacer 3” x 20” Long Copper (thickness to suit) (customer supplied)
Rev. #12: 10-29-19 063929 Page 9 of 10
UG-1: Services Greenbook Requirements for Bus Duct Entrance Termination Unit for Use With Pad-Mounted Transformers
Bus Duct Termination Assembly − Details (continued)
1-1/8”
CL
of Transformer’s Low-Voltage Compartment
Height
1-1 Col2 Compa 1/8” Col4 Col5 Col6 Col7 Col8 artment Col10 3/4” Col12 Col13 1-3/4” 1-3/4” 1-3/4” 1-3/4” 1-3/4” 1-3/4” 3/4”
3/4”
1-3/4”
1-3/4”3/4”
3/4”
1-3/4”
1-3/4”3/4”
3/4”
1-3/4”
1-3/4”8” 8” 8” 8” 8” 8” 8” 8” 8” 8” 3” 3” 3” 3” 3” 3 3” 3” 3” 3” 3” 3 3” 3 3” 3 3” 3 1-3/4”
Concrete Pad
of Bus to Door or Metal
Detail E Copper Bus Bar Extension (see Table 1 on Page 5)
Table 3 Copper Conductor Requirements [3]
Concrete Footing 12” Dia. x 12” H
Steel Flange
Concrete Footing
Concrete Pad (weld-on type)
12” Dia. x 12” H Code 025391
California Referenced Standards Code High relevance — show source text
|100 psf|1 hr
23 min|||7|1, 2|11/3| |F/C-4-RC-9|4″|4″ deep (4370 psi);1/4″ reinforcement bars
at 6″ pitch with3/4″ cover;1/4″ main rein-
forcement bars at 4″ pitch perpendicular
with1/2″ cover; 13′1″ span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-10|4″|4″ thick (5140 psi) deck;1/4″ reinforce-
ment bars at 71/2″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|1 hr
16 min|||7|1, 5|11/4| |F/C-4-RC-11|4″|4″ thick (4000 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom of slab; 6′6″
span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-12|4″|4″ deep (2380 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom surface;
6′6″ span restrained.|150 psf|1 hr
3 min|||7|1, 2|1| |F/C-4-RC-13|41/2″|41/2″ thick (5200 psi) deck;1/4″ reinforce-
ment bars at 71/4″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-14|41/2″|41/2″ deep (2525 psi) concrete deck;1/4″
reinforcement bars at 71/2″ pitch with7/8″
cover;3/8″ main reinforcement bars at
33/8″ pitch perpendicular with1/2″ cover;
13′1″ span restrained.|150 psf|42 min|||7|1, 5|2/3| |F/C-4-RC-15|41/2″|41/2″ deep (4830 psi) concrete deck;
11/2″ × No.CRSC § 1115A.6.2.7 Medium relevance — show source text
2. Noncircular cross section. Handrail gripping surfaces with a noncircular cross section shall have a perimeter dimension of 4 inches (102 mm) minimum and 6 [1] / 4 inches (159 mm) maximum, and a cross-section dimension of 2 [1] / 4 inches (57 mm) maximum.
1115A.6.2.7 Fittings. Handrails shall not rotate within their fittings.
11A-12 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HOUSING ACCESSIBILITY
SECTION 1116A—HAZARDS ON ACCESSIBLE ROUTES
1116A.1 Warning curbs. Abrupt changes in level exceeding 4 inches (101.6 mm) in vertical dimension, such as changes in level at plant- ers or fountains located in or adjacent to walks, sidewalks or other pedestrian ways shall be identified by curbs or other approved barriers projecting at least 6 inches (152.4 mm) in height above the walk or sidewalk surface to warn the blind of a potential drop-off.
Exceptions:
1. Between a walk or sidewalk and an adjacent street or driveway. 2. When a guardrail or handrail is provided with edge protection in accordance with Section 1012.10.1.
1116A.2 Headroom clearance. Walks, pedestrian ways, and other circulation spaces, which are part of the required egress system, shall have a minimum clear headroom as required in Section 1003.2. Other walks, pedestrian ways and circulation spaces shall have a mini- mum clear headroom of 80 inches (2032 mm). If the vertical clearance of an area adjoining an accessible route is reduced to less than 80 inches (2032 mm), a guardrail or other barrier having its leading edge at or below 27 inches (686 mm) above the finished floor shall be provided.
Exception: Doorways and archways less than 24 inches (610 mm) in depth may have a minimum clear headroom of 80 inches (2032 mm). (See Section 1126A for door requirements.)
1116A.3 Overhanging obstructions. Any obstruction that overhangs a pedestrian way shall be a minimum of 80 inches (2032 mm) above the walking surface as measured from the bottom of the obstruction. (See Figure 11A-1B.) Where a guy support is used parallel to a path of travel, including, but not limited to, sidewalks, a guy brace, sidewalk guy or similar device shall be used to prevent an over- hanging obstruction. (See Section 1116A.2 for required headroom clearance.)
Exception: Door closers and door stops shall be permitted to be 78 inches (1981 mm) minimum above the finish floor or ground.
1116A.4 Free-standing signs. Wherever signs mounted on posts or pylons protrude from the post or pylons and the bottom edge of the sign is less than 80 inches (2032 mm) above the finished floor or ground level, the edges of such signs shall be rounded or eased and the corners shall have a minimum radius of 0.125 inches (see Section 1116A.2 for required headroom clearance).
CRSC § 0.113 Medium relevance — show source text
or 16 ga.
staple galvanized, 15/8″ long,7/16″ or
1″ crown; or 15/8″ screws, Type W or S|7|7| |Wood structural panels, combination subfloor underlayment to framing|Wood structural panels, combination subfloor underlayment to framing|Wood structural panels, combination subfloor underlayment to framing|Wood structural panels, combination subfloor underlayment to framing|Wood structural panels, combination subfloor underlayment to framing| |38|3/4″ and less|Deformed (2″ × 0.113″) or
Deformed (2″ × 0.120″) nail; or
8d common (21/2″ × 0.131″) nail|6|12| |39|7/8″ – 1"|8d common (21/2″ × 0.131″) nail; or
Deformed (21/2″ × 0.131″); or
Deformed (21/2″ × 0.120″) nail|6|12| |40|11/8″ − 11/4″|10d common (3″ × 0.148″) nail; or
Deformed (21/2″× 0.131″); or
Deformed (21/2″ × 0.120″) nail|6|12| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s; 1 ksi = 6.895 MPa.
a. Nails are smooth-common, box or deformed shanks except where otherwise stated. Nails used for framing and sheathing connections are carbon steel and shall have mini-
mum average bending yield strengths as shown: 80 ksi for shank diameter of 0.192 inch (20d common nail), 90 ksi for shank diameters larger than 0.142 inch but not larger than
0.177 inch, and 100 ksi for shank diameters of 0.142 inch or less. Connections using nails and staples of other materials, such as stainless steel, shall be designed by accepted
engineering practice or approved under Section R104.2.2.
b. RSRS-01 is a Roof Sheathing Ring Shank nail meeting the specifications in ASTM F1667.
c. Nails shall be spaced at not more than 6 inches on center at all supports where spans are 48 inches or greater.
d. Four-foot by 8-foot or 4-foot by 9-foot panels shall be applied vertically.
e. Spacing of fasteners not included in this table shall be based on Table R602.3(2).
f. For wood structural panel roof sheathing attached to gable end roof framing and to intermediate supports within 48 inches of roof edges and ridges, nails shall be spaced at 4
inches on center where the ultimate design wind speed is greater than 130 mph in Exposure B or greater than 110 mph in Exposure C. Fastener spacing applies where roof
framing specific gravity is 0.42 or larger. Where roof framing specific gravity is greater than or equal to 0.35 but less than 0.42 in accordance with AWC NDS, fastening of roof
sheathing shall be with RSRS-03 (21/2″ × 0.131″ × 0.281″ head) nails.
g.CRSC § 0.35 Medium relevance — show source text
Required diaphragm lengths are to be provided at each end of the structure.
e. Multiplying required diaphragm lengths by 0.35 is permitted if all panel edges are blocked.
f. Multiplying required diaphragm lengths by 0.9 is permitted if all panel edges are secured with screws spaced at 4 inches o.c.
g. To determine the minimum diaphragm length for buildings with ceiling heights of 9 feet or 10 feet values in this table shall be multiplied by 1.15.|For SI: 1 inch = 25.4 mm, 1 mile per hour = 0.447 m/s, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.
a. Ceiling diaphragm is composed of1/2-inch gypsum board (min. thickness) secured with screws spaced at 6 inches o.c. at panel edges and 12 inches o.c. infield. Use No. 8
screws (min.) where framing members have a designation thickness of 54 mils or less and No. 10 screws (min.) where framing members have a designation thickness greater
than 54 mils.
b. Maximum aspect ratio (length/width) of diaphragms is 2:1.
c. Building width is in the direction of horizontal framing members supported by the wall studs.
d. Required diaphragm lengths are to be provided at each end of the structure.
e. Multiplying required diaphragm lengths by 0.35 is permitted if all panel edges are blocked.
f. Multiplying required diaphragm lengths by 0.9 is permitted if all panel edges are secured with screws spaced at 4 inches o.c.
g. To determine the minimum diaphragm length for buildings with ceiling heights of 9 feet or 10 feet values in this table shall be multiplied by 1.15.|For SI: 1 inch = 25.4 mm, 1 mile per hour = 0.447 m/s, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.
a. Ceiling diaphragm is composed of1/2-inch gypsum board (min. thickness) secured with screws spaced at 6 inches o.c. at panel edges and 12 inches o.c. infield. Use No. 8
screws (min.) where framing members have a designation thickness of 54 mils or less and No. 10 screws (min.) where framing members have a designation thickness greater
than 54 mils.
b. Maximum aspect ratio (length/width) of diaphragms is 2:1.
c. Building width is in the direction of horizontal framing members supported by the wall studs.
d. Required diaphragm lengths are to be provided at each end of the structure.
e. Multiplying required diaphragm lengths by 0.35 is permitted if all panel edges are blocked.
f. Multiplying required diaphragm lengths by 0.9 is permitted if all panel edges are secured with screws spaced at 4 inches o.c.
g. To determine the minimum diaphragm length for buildings with ceiling heights of 9 feet or 10 feet values in this table shall be multiplied by 1.15.|For SI: 1 inch = 25.4 mm, 1 mile per hour = 0.447 m/s, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.
a.CRSC § 0.42 Medium relevance — show source text
Spacing of fasteners not included in this table shall be based on Table R602.3(2).
f. For wood structural panel roof sheathing attached to gable end roof framing and to intermediate supports within 48 inches of roof edges and ridges, nails shall be spaced at 4
inches on center where the ultimate design wind speed is greater than 130 mph in Exposure B or greater than 110 mph in Exposure C. Fastener spacing applies where roof
framing specific gravity is 0.42 or larger. Where roof framing specific gravity is greater than or equal to 0.35 but less than 0.42 in accordance with AWC NDS, fastening of roof
sheathing shall be with RSRS-03 (21/2″ × 0.131″ × 0.281″ head) nails.
g. Gypsum sheathing shall conform to ASTM C1396 and shall be installed in accordance with ASTM C1280 or GA 253 . Fiberboard sheathing shall conform to ASTM C208.
h. Spacing of fasteners on floor sheathing panel edges applies to panel edges supported by framing members and required blocking and at floor perimeters only. Spacing of fasteners
on roof sheathing panel edges applies to panel edges supported by framing members and required blocking. Blocking of roof or floor sheathing panel edges perpendicular to the
framing members need not be provided except as required by other provisions of this code. Floor perimeter shall be supported by framing members or solid blocking.
i. Where a rafter is fastened to an adjacent parallel ceiling joist in accordance with this schedule, provide two toe nails on one side of the rafter and toe nails from the ceiling joist
to top plate in accordance with this schedule. The toe nail on the opposite side of the rafter shall not be required.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s; 1 ksi = 6.895 MPa.
a. Nails are smooth-common, box or deformed shanks except where otherwise stated. Nails used for framing and sheathing connections are carbon steel and shall have mini-
mum average bending yield strengths as shown: 80 ksi for shank diameter of 0.192 inch (20d common nail), 90 ksi for shank diameters larger than 0.142 inch but not larger than
0.177 inch, and 100 ksi for shank diameters of 0.142 inch or less. Connections using nails and staples of other materials, such as stainless steel, shall be designed by accepted
engineering practice or approved under Section R104.2.2.
b. RSRS-01 is a Roof Sheathing Ring Shank nail meeting the specifications in ASTM F1667.
c. Nails shall be spaced at not more than 6 inches on center at all supports where spans are 48 inches or greater.
d. Four-foot by 8-foot or 4-foot by 9-foot panels shall be applied vertically.
e. Spacing of fasteners not included in this table shall be based on Table R602.3(2).
f. For wood structural panel roof sheathing attached to gable end roof framing and to intermediate supports within 48 inches of roof edges and ridges, nails shall be spaced at 4
inches on center where the ultimate design wind speed is greater than 130 mph in Exposure B or greater than 110 mph in Exposure C. Fastener spacing applies where roof
framing specific gravity is 0.42 or larger.CRSC § 406.5.4 Medium relevance — show source text
For purposes of calculating the interior area of the side, the height shall not exceed 7 feet (2134 mm).
Allowable tier areas in Table 406.5.4 shall be increased for open parking garages constructed to heights less than the table maximum. The gross tier area of the garage shall not exceed that permitted for the higher structure. Not fewer than three sides of each such larger tier shall have continuous horizontal openings not less than 30 inches (762 mm) in clear height extending for not less than 80 percent of the length of the sides. All parts of such larger tier shall be not more than 200 feet (60 960 mm) horizontally from such an opening. In addition, each such opening shall face a street or yard with access to a street with a width of not less than 30 feet (9144 mm) for the full length of the opening, and standpipes shall be provided in each such tier.
Open parking garages of Type II construction, with all sides open, shall be unlimited in allowable area where the building height does not exceed 75 feet (22 860 mm). For a side to be considered open, the total area of openings along the side shall be not less than 50 percent of the interior area of the side at each tier and such openings shall be equally distributed along the length of the tier. For purposes of calculating the interior area of the side, the height shall not exceed 7 feet (2134 mm). All portions of tiers shall be within 200 feet (60 960 mm) horizontally from such openings or other natural ventilation openings as defined in Section 406.5.2. These openings shall be permitted to be provided in courts with a minimum dimension of 20 feet (6096 mm) for the full width of the openings.
406.5.6 Fire separation distance. Exterior walls and openings in exterior walls shall comply with Table 601 and Table 705.5. The distance to an adjacent lot line shall be determined in accordance with Section 705 and Table 705.5.
[BE] 406.5.7 Means of egress. Where persons other than parking attendants are permitted, open parking garages shall meet the means of egress requirements of Chapter 10. Where persons other than parking attendants are not permitted, there shall be not fewer than two exit stairways. Each exit stairway shall be not less than 36 inches (914 mm) in width. Lifts shall be permitted to be installed for use of employees only, provided that they are completely enclosed by noncombustible materials.
[F] 406.5.8 Standpipe system. An open parking garage shall be equipped with a standpipe system as required by Section 905.3.
2025 CALIFORNIA BUILDING CODE 4-17
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE
406.5.9 Enclosure of vertical openings. Enclosure shall not be required for vertical openings except as specified in Section 406.5.7.
406.5.10 Ventilation. Ventilation, other than the percentage of openings specified in Section 406.5.2, shall not be required.
406.5.11 Prohibitions. The following uses and alterations are not permitted:
- Vehicle repair work.
- Parking of buses, trucks and similar vehicles.
- Partial or complete closing of required openings in exterior walls by tarpaulins or any other means.
- Dispensing of fuel.
CRSC § 12-7 Medium relevance — show source text
Fire tests of building
construction and materials.|SFM|Part 2, Section 703| |Chapter 12-7-2|Reserved||| |Chapter 12-7-3|Fire-resistive standards.
Fire testing furnaces.|SFM|Part 9, Section 3001| |Chapter 12-7-4|Fire-resistive standards.
Fire door assembly tests.|SFM|Part 2, Section 716| |Chapter 12-7-5|Fire-resistive standards. Interior
finish of decorative material.|SFM|Part 2, Chapter 8
Part 9, Chapter 8| |Chapter 12-7A|Materials and construction methods for
exterior wildfire exposure|SFM|Part 7, Chapter 5| |Chapter 12-8-1|Fire-resistive standards for fire protection|SFM|Part 2, Sections 408.14 and 435.6.2| |Appendix 12-8-1A|Calculation of the total rate of heat and carbon
monoxide or carbon dioxide production|SFM|| |Appendix 12-8-1B|Guide to mounting techniques for wall and
ceiling interior finish material|SFM|| |Chapter 12-10-1|Exits. Power-operated exit doors.|SFM|Part 2, Sections 408.4.2, 1010.1.4.2, 1010.1.9.1| |Chapter 12-10-2|Exits. Single-point latching or locking devices.|SFM|Part 2, Section 1010.2.2
Part 9, Section 1010.2.2| |Chapter 12-10-3|Exits. Emergency exit and panic hardware.
|SFM|Part 9, Section 1009.12| |Chapter 12-11A,
12-11B|Detectable warning products and directional
surfaces|DSA|Part 2, Sections 1112A.9, 1116A.5, 11B-247,
11B-406.5.12, 11B-705, 11B-810.5.2| |Chapter 12-12|Reserved||| |Chapter 12-13|Standards for insulating material|CA/SFM|Part 2.5, Section R302.10.1
Part 6, Section 110.8
Part 9, Section 720, Table 721.1(1)
Part 11, Section A5.504.4.8| |Chapter 12-16-1|California standard for earthquake-actuated
automatic gas shutoff systems|DSA|Part 2, Chapters 16 and 16A
Part 5, Section 1211.8| |Chapter 12-16-2|California standard for residential excess flow
actuated automatic gas shutoff valves|DSA|Part 5, Section 1209.1| |Chapter 12-31C|Radiation shielding|DPH|Part 2, Section 3102C| |Chapter 12-71|Air filters|SFM|Part 4, Sections 401.2, 509.2.3, 509.2.3.4
Part 6, Section 120.1| |Chapter 12-72-1|Protective signaling systems.
Standard test procedures.|SFM|| |Chapter 12-72-2|Protective signaling systems.
Frequently asked questions
What exact filter size does the frame accept?
The standard specifies a nominal 20 × 20 inch filter unit to be received by the metal filter frame in the duct. § 12-71-100(a).2.
Where must air velocity be measured?
Air velocity must be measured at the discharge end of the duct using an Alnor Velometer Anemometer; the target is approximately 200 ft/min. § 12-71-100(a).4.
How long are flames applied during the test?
Flames are applied for 3 minutes while observing both faces and recording smoke readings. § 12-71-100(b).1–2.
What are the smoke-area cutoffs for Class 1 vs Class 2?
Class 1: area < 1.5 in² (and no downstream flame/sparks). Class 2: area ≤ 6.0 in² with limited burning/smoke and no projecting flames that would ignite external materials. § 12-71-100(c).
Are low‑flash adhesives allowed on filters?
No — liquid adhesives used on filters must have a flash point ≥ 325°F (163°C) (Cleveland open cup). § 12-71-100(d).
More in California Referenced Standards Code
- Administration and scope — CRSC Chapter 12 overview
- Air filter standards (Chapter 12‑71)
- Building and facility access / accessibility standards (Chapters 12‑11A, 12‑11B)
- Engineering regulations — quality and design of construction materials (12‑16 series)
- Exits and means of egress (Chapters 12‑10 series)
- Protective signaling systems and detectors (Chapters 12‑72‑1, ‑2, ‑3)
- Radiation shielding standards (Chapter 12‑31C)
- Referenced standards index / cross‑reference table (Part 12 listing of referenced standards)
- Releasing systems for security bars (egress-release standards)
- Standards for insulating materials (Chapter 12‑13)
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