CWUIC · California Wildland-Urban Interface Code

How are under-deck and horizontal-projection (soffit/eave underside) tests specified?

If you want to use a test result instead of prescriptive materials for enclosed eaves/soffits under the CWUIC, test the soffit assembly to **SFM 12‑7A‑3** (or ASTM E2957) using a **300 ± 15 kW** burner on **4 ft × 2 ft** specimens for a **10‑minute** exposure, meet the three acceptance criteria (no flame penetration, no structural failure, no sustained combustion), and run at least **three** replicate tests per the code.

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Last reviewed: July 6, 2026

What the code requires — plain English

The CWUIC requires that enclosed eaves/soffits and other horizontal projections meet either prescriptive material choices (noncombustible, ignition‑resistant, fire‑retardant‑treated, specified lumber or fire‑resistance ratings) or meet performance tests that simulate direct flame to the underside. The prescriptive list and the allowance to use test‑rated boxed‑in soffit assemblies are in § 504.3.

Where a performance test is used for the underside of horizontal projections (soffits/eaves/floor projections), the State Fire Marshal standard SFM 12‑7A‑3 (Horizontal Projection Underside) sets the test fixture, burner output, specimen size, conditioning and acceptance criteria; those performance results are invoked in § 504.7.1 and the acceptance criteria are summarized in § 504.7.2.

The single most important rule: if you choose to comply by test instead of prescriptive materials, use the exact SFM/ASTM procedure called out in the code (SFM 12‑7A‑3 or ASTM E2957) and meet the acceptance criteria — absence of flame penetration, structural failure, and sustained combustion.

Requirements in detail

Scope and when test methods apply

What assemblies: horizontal soffits of roof eaves, floor projections and exposed underfloor areas (defined as eaves and soffit) may be judged by the underside performance test rather than prescriptive materials. § 504.3 and SFM 12‑7A‑3 define the scope.
Two possible test standards referenced by the CWUIC: ASTM E2957 (see § 504.3/504.7 references) and SFM 12‑7A‑3 (explicitly called out for the horizontal projection underside test).

Test fixture, inputs and specimen

Parameter / decision item	Required value or description	Code reference
Test standard (horizontal projection underside)	SFM Standard 12‑7A‑3 (Horizontal Projection Underside) — alternative allowed: ASTM E2957 where referenced	§ 504.7.1, SFM 12‑7A‑3
Burner heat output (direct flame)	300 ± 15 kW net heat output (diffusion burner, 12" x 12")	SFM 12‑7A‑3
Duration of direct flame exposure	10 minutes, continue observation up to 40 minutes (see acceptance)	SFM 12‑7A‑3; acceptance criteria referenced in § 504.7.2
Specimen size / assembly fit	4 ft wide × 2 ft deep specimen installed in the test module; typical eave framing and joints included	SFM 12‑7A‑3
Burner / specimen geometry	Horizontal surface of the assembly positioned 84 inches (2.1 m) from top of burner; burner centered, 0.75 inch (20 mm) from wall; burner top 12 inches (300 mm) from floor	SFM 12‑7A‑3 (conduct/test setup)
Number of test specimens	3 replicates; if one of the three fails, run 3 additional tests and all must pass	§ 504.7.2; SFM 12‑7A‑3
Conditioning / moisture content	Lumber 8–12% (oven‑dry basis) and sheathing ≤ 8%; condition to constant weight or 30 days at 73 ± 4°F, 50 ± 5% RH	SFM 12‑7A‑3
Test atmosphere	Ambient airflow (no forced draft) during test	SFM 12‑7A‑3
Reporting requirements	Specimen construction, material descriptions, moisture content, time/location of any penetration; details for early termination	SFM 12‑7A‑3 (reporting)

Conditions of acceptance (what "pass" means)

Absence of flame penetration of the eaves or horizontal projection assembly at any time. § 504.7.2, SFM 12‑7A‑3.
Absence of structural failure of the eaves/horizontal projection subassembly at any time. § 504.7.2.
Absence of sustained combustion of any kind at the conclusion of the test observation period (the code references a 40‑minute total observation in acceptance language). § 504.7.2; SFM 12‑7A‑3.

Interaction with prescriptive material options

If the soffit/under‑projection meets one of the prescriptive materials in § 504.3 (noncombustible, ignition‑resistant, specified lumber sizes, 1‑hour exterior fire resistance, FRT wood listed for exterior use, etc.), testing is not required for that compliance path. Boxed‑in soffit assemblies may instead be shown to meet the performance criteria by the ASTM E2957 procedure or SFM 12‑7A‑3 as specifically allowed in § 504.3.

Exceptions & special cases

Structural columns and beams: Not required to be protected under § 504.7.1 when constructed of sawn lumber or glue‑laminated wood with the smallest nominal dimension 4 inches (102 mm) (sawn or glued planks must be splined/tongue‑and‑groove/close‑set and well spiked). This is an explicit exception in § 504.7.1.
Boxed‑in soffits: CWUIC permits boxed‑in soffit assemblies to comply by test — either ASTM E2957 or SFM 12‑7A‑3 — provided the assembly meets the conditions of acceptance in § 504.7.2 (or ASTM/E2957 acceptance language). § 504.3 and § 504.7.2.
Deck under‑deck tests are separate: Under‑deck (decking) tests use SFM 12‑7A‑4 or 12‑7A‑4A and different burner intensities/durations (e.g., 80 ±4 kW under‑deck exposure for Part A / 3 minutes for alternate method), so do not confuse those with the horizontal projection underside test. CWUIC references these separately (see referenced standards and § 504.7.3).

Common mistakes

Confusing the horizontal projection underside test (SFM 12‑7A‑3, 300 kW / 10 min) with the under‑deck/deck test (SFM 12‑7A‑4 / 12‑7A‑4A, 80 kW / 3 min + brand exposure) — they are different standards with different criteria.
Failing to condition materials or to verify moisture content per the standard (lumber 8–12%, sheathing ≤ 8%) before testing — this invalidates test reproducibility. SFM 12‑7A‑3 requires conditioning and moisture measurement.
Incorrect burner setup or output — the test requires a 12" × 12" diffusion burner and verification of 300 ±15 kW output prior to running the specimen. Run the verification without the specimen in place as required. SFM 12‑7A‑3.
Misreading exposure vs. observation time: the direct flame exposure is 10 minutes, but the acceptance/observation period extends to 40 minutes in the standard/acceptance language — sustained combustion after exposure can cause failure.
Assuming a single passing specimen suffices — the code requires 3 passing replicates, with the option to run 3 more if one of the first three fails. § 504.7.2; SFM 12‑7A‑3.

Worked example — concrete scenario

Scenario: You have a boxed‑in roof eave soffit you want to use on homes in a wildfire area. You choose the test path.

Step 1 — Test standard selection: elect to test under SFM 12‑7A‑3 for horizontal projection underside performance as permitted in § 504.3.

Step 2 — Prepare specimens: fabricate three representative soffit subassemblies sized 4 ft × 2 ft with the actual framing, joints and soffit material you will install. Condition lumber to 8–12% moisture content and sheathing ≤ 8%, per 12‑7A‑3.

Step 3 — Test setup: install the specimen into the SFM fixture so the horizontal soffit surface is 84 inches above the top of the burner; use the required 12" × 12" diffusion burner, center it and set 300 ± 15 kW heat output (verify without specimen).

Step 4 — Run & observe: ignite and maintain the 10‑minute direct flame exposure; observe and record any flame penetration, structural failure or ignition during the exposure and for the total observation period (up to 40 minutes if needed). Report materials, moisture content and times/locations of any penetration per the report requirements.

Step 5 — Acceptance: if all three specimens show no flame penetration, no structural failure, and no sustained combustion at the end of observation, the assembly meets the acceptance criteria in § 504.7.2 and may be accepted in lieu of prescriptive soffit materials. If one specimen fails, three additional tests must be run and all three additional tests must pass.

Related provisions

§ 504.3 — Protection of enclosed eaves (prescriptive options and testing options).
§ 504.7.1 — Underside of projections (lists allowable protections and references the test methods).
§ 504.7.2 — Conditions of acceptance for ASTM E2957 / underside tests (absence of flame penetration, structural failure, sustained combustion).
SFM 12‑7A‑3 — Horizontal Projection Underside test standard (fixture, burner, specimen, conditioning, conduct, reporting, acceptance).
SFM 12‑7A‑4 / 12‑7A‑4A — Decking / under‑deck test standards (different burner intensity/duration; separate from soffit/under‑projection).

Code references

Grounded in the retrieved California Wildland-Urban Interface Code — click a citation to read the verbatim passage:

CWUIC § 12-7 High relevance — show source text
1. Test Fixture. The test fixture shall be as described in SFM 12-7A-1, with the exception that the top soffit projection of the wall assembly fixture is modified to facilitate installation and removal of eave assemblies. Gypsum board (or equivalent) is used to create a noncombustible wall surface in the 4 x 8 ft. opening in the wall test fixture.
2. Eaves assembly. Fit the eave assembly into the test module so that the horizontal surface of the assembly is 84 inches (2.1 m) from the top of the burner.
3. Moisture content. Measure the moisture content of the wooden members of the assembly using a moisture meter (ASTM D4444), and for sheathing products, by methods outlined in ASTM D4442.
4. Sealing. Seal the edges and ends with ceramic wool or comparable material to prevent flame penetration in these locations of the eave assembly.
12-7A-3.8 Conduct of Tests.
1. Airflow. The wall test shall be conducted under conditions of ambient airflow.
2. Number of tests. Conduct the tests on three replicate eaves assemblies.
3. Burner output verification. Without the eaves assembly in place, adjust the burner for 300 ± 15 kW output. Extinguish the burner.
4. Burner positioning. Center the burner with respect to the width of the eaves wall assembly and 0.75 inch (20 mm) from the wall. The distance from the floor to the top of the burner shall be 12 inches (300 mm).
5. Procedure.
5.1. Ignition. Ignite the burner, controlling for a constant 300 ± 15 kW output. 5.2. Flame exposure. Continue the exposure until flame penetration of the eaves occurs or for a 10-minute period.

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MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE

5.3. Continued combustion. If penetration does not occur, continue observation for an additional 30 minutes or until all combustion has ceased.

Note: An infrared thermometer has been found to be useful to detect the increase of temperature on the back side of the eaves and as an aid to identify the areas of potential combustion. 6. Observations. Note the time, location and nature of flame penetration.

12-7A-3.9 Report. The report shall include a description of the eaves material, details of the construction of the eaves, moisture content of the framing and wood-based soffit elements as applicable, and point of flame penetration. Provide details on the time and reasons for early termination of the test.

12-7A-3.10 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance.
1. Absence of flame penetration of the eaves or horizontal projection assembly at any time.
2. Absence of structural failure of the eaves or horizontal projection subassembly at any time.
3. Absence of sustained combustion of any kind at the conclusion of the 40-minute test.
FIGURE 1 — EAVES TEST ASSEMBLY
CWUIC § 504.3 High relevance — show source text
504.3 Protection of enclosed eaves. The exposed underside of enclosed roof eaves and soffits shall be protected on the exposed underside by one or more of the following:

1. Noncombustible materials.

2. Ignition-resistant building materials. 3. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

4. 2-inch (51 mm) nominal dimension lumber . 5. 1-inch (25 mm) nominal fire-retardant-treated lumber or [3] / 4 -inch (19.1 mm) nominal fire-retardant-treated plywood, identified for exterior use and complying with Section 2303.2 of the California Building Code . 6. Boxed-in roof eave soffit assemblies with an underside that meets the performance criteria in Section 504.7.2 when tested in accordance with the test procedures set forth in ASTM E2957. 7. Boxed-in roof eave soffit assemblies with an underside that meets the performance criteria in accordance with the test proce- dures set forth in SFM Standard 12-7A-3.

Facias are required and shall be ignition-resistant building materials , fire-retardant-treated wood labeled for exterior use and complying with Section 2303.2 of the California Building Code, materials approved for not less than 1-hour fire-resistance-rated construction or 2-inch (51 mm) nominal dimension lumber.

504.3.1 Protection of open eaves. The exposed roof deck on the underside of unenclosed roof eaves shall consist of one or more of the following:

1. Noncombustible material.

2. Ignition-resistant building material. 3. Fire-retardant-treated wood labeled for exterior use and complying with Section 2303.2 of the California Building Code. 4. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

5. 2-inch (51 mm) nominal dimension lumber. 6. One layer of [5] / 8 -inch (16 mm) Type X gypsum sheathing applied behind an exterior covering on the underside of the roof deck.

7. The exterior portion of a 1-hour fire-resistance-rated exterior assembly, as tested in accordance with ASTM E119 or UL 263, applied to the underside of the roof deck designed for exterior fire exposure, including assemblies using the gypsum panel and sheathing products listed in the Gypsum Association Fire Resistance Design Manual.

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SPECIAL BUILDING CONSTRUCTION REGULATIONS

Facias, if provided, shall be of fire-retardant-treated wood labeled for exterior use and complying with Section 2303.2 of the Cali- fornia Building Code, ignition-resistant building materials, materials approved for not less than 1-hour fire-resistance-rated construction or 2-inch (51 mm) nominal dimension lumber.
CWUIC § 12-7 High relevance — show source text
504.8

12-7A-3: Horizontal Projection Underside. A fire resistance test standard consisting of a 300 kW intensity direct flame exposure for a 10-minute duration

504.3, 504.7, 504.7.1

12-7A-4: Decking. A two-part test consisting of a heat release rate (Part A) deck assembly combustion test with an under deck exposure of 80 kW intensity direct flame for a 3-minute duration, and a (Part B) sustained deck assembly combustion test consisting of a deck upper surface burning ember exposure with a 12 mph wind for 40 minutes using a 2.2 lb (1kg) burning “Class A” size 12" × 12" × 2.25" (300 mm × 300 mm × 57 mm) roof test brand

504.7.3.2

12-7A-4A: Decking Alternate Method A. A heat release rate deck assembly combustion test with an under deck exposure of 80 kW intensity direct flame for a 3-minute duration

504.7.3.2

State Fire Marshal’s Guidelines for Fire Hydrant Markings Along State Highways and Freeways, May 1988

404.8

UL UL LLC, 333 Pfingsten Road, Northbrook, IL 60062-2096

9—2009: Fire Tests of Window Assemblies—with Revisions through March 2020

504.8

10B—2008: Fire Tests of Door Assemblies—with Revisions through May 2020

504.9

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REFERENCED STANDARDS

10C—2016: Positive Pressure Fire Tests of Door Assemblies—with Revisions through May 2021

504.9

94—2023: Tests for Flammability of Plastic Materials for Parts in Devices and Appliances

504.9.2

263—2011: Fire Tests of Building Construction and Materials—with Revisions through March 2022

501.3, 504.3, 504.3.1, 504.5, 504.7, 504.7.1

723—2018: Test for Surface Burning Characteristics of Building Materials

202, 501.4.1, 503.2.4, 504.7.3.2, 504.7.3.3

790— 2022 : Standard Test Methods for Fire Tests of Roof Coverings

504.2, 504.2.1.2, 504.11.6

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CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE

APPENDIX A – GENERAL REQUIREMENTS
CWUIC § 12-7 High relevance — show source text
SPECIAL BUILDING CONSTRUCTION REGULATIONS

8. The underside of a floor projection assembly that meets the performance criteria in accordance with the test procedures set forth in SFM Standard 12-7A-3.

504.7.1 Underside of projections. The underside of projections shall be enclosed to grade in accordance with the requirements of this chapter or the underside of the exposed underfloor shall be protected by one or more of the following:

1. Noncombustible material.

2. Ignition-resistant building material shall be labeled for exterior use and shall meet the requirements of Section 503.2. 3. Fire-retardant-treated wood shall be labeled for exterior use and shall meet the requirements of Section 2303.2. 4. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

5. One layer of [5] / 8 -inch (15.9 mm) Type X gypsum sheathing applied behind an exterior covering on the underside of the floor projection. 6. The exterior portion of a 1-hour fire-resistance-rated exterior assembly, as tested in accordance with ASTM E119 or UL 263, applied to the underside of the floor, including assemblies using the gypsum panel and sheathing products listed in the Gypsum Association Fire Resistance Design Manual. 7. The underside of a floor assembly that meets the performance criteria in Section 504.7.2 when tested in accordance with the test procedures set forth in ASTM E2957. 8. The underside of a floor assembly that meets the performance criteria in accordance with the test procedures set forth in SFM Standard 12-7A-3.

Exception: Structural columns and beams are not required to be protected in accordance with Section 504.7.1 when constructed with sawn lumber or glue-laminated wood with the smallest minimum nominal dimension of 4 inches (102 mm). Sawn or glue- laminated planks shall be splined, tongue-and-groove, or set close together and well spiked.

504.7.2 Conditions of acceptance for ASTM E2957. The ASTM E2957 test shall be conducted on a minimum of three test specimens and meet the conditions of acceptance in Items 1 through 3. If any one of the three tests does not meet the conditions of acceptance, three additional tests shall be performed. All three additional tests must meet the conditions of acceptance. 1. Absence of flame penetration of the eaves or horizontal projection assembly at any time. 2. Absence of structural failure of the eaves or horizontal projection subassembly at any time. 3. Absence of sustained combustion of any kind at the conclusion of the 40-minute test.

504.7.3 Decks. The walking surface material of decks, porches, balconies and stairs shall comply with the requirements of Sections 504.7.3.1 through 504.7.3.4.

504.7.3.1 Flashing. A minimum of a 6-inch (150 mm) metal flashing, applied vertically on the exterior of the wall, shall be installed at all deck-to-wall intersections.
CWUIC § 12-7 High relevance — show source text
Natural gas, methane or propane shall be supplied to the burner through a metered control system. The gas supply to the burner shall produce a net heat output of 300 ± 15 kW throughout the flame exposure. Burner output can be determined from HRR or calculated from the gas flow rate, temperature and pressure. 2. Infrared temperature analyzer (optional). Intended for monitoring the temperature change of the inside of the eaves. 3. Moisture content. Prior to testing, all materials (lumber and soffit material) shall be conditioned to a constant weight or for a minimum of 30 days at 73 ± 4°F (23 ± 2°C) and 50 ± 5% relative humidity, whichever occurs first. Constant weight shall be defined as occurring when the change in test material weight is less than or equal to 2 percent in a 24-hour period. Lumber moisture content shall be between 8 and 12 percent (oven-dry basis) and sheathing shall not exceed 8 percent (oven-dry basis).

12-7A-3.6 Materials.
1. Framing. The materials used shall be representative of the grades that would be typical of eave construction and installed in the eave’s subassembly as per accepted construction practices.
2. Soffit. Material selected for the test.
12-7A-3.7 Test system preparation (Figure 1).
1. Eaves fabrication. The 4-foot-wide by 2-foot (1.2 m by 0.6 m) test specimen shall be constructed to fit into a 4-foot-wide (1.2 m) space at the top of the test assembly described in SFM 12-7A-1. Normal eave framing, joints in soffit material and other typical features present in the constructed assembly shall be present in the test specimen.
2. Test Fixture. The test fixture shall be as described in SFM 12-7A-1, with the exception that the top soffit projection of the wall assembly fixture is modified to facilitate installation and removal of eave assemblies. Gypsum board (or equivalent) is used to create a noncombustible wall surface in the 4 x 8 ft. opening in the wall test fixture.
3. Eaves assembly. Fit the eave assembly into the test module so that the horizontal surface of the assembly is 84 inches (2.1 m) from the top of the burner.
4. Moisture content. Measure the moisture content of the wooden members of the assembly using a moisture meter (ASTM D4444), and for sheathing products, by methods outlined in ASTM D4442.
5. Sealing. Seal the edges and ends with ceramic wool or comparable material to prevent flame penetration in these locations of the eave assembly.
12-7A-3.8 Conduct of Tests.
1. Airflow. The wall test shall be conducted under conditions of ambient airflow.
2. Number of tests. Conduct the tests on three replicate eaves assemblies.
3. Burner output verification. Without the eaves assembly in place, adjust the burner for 300 ± 15 kW output. Extinguish the burner.
4. Burner positioning. Center the burner with respect to the width of the eaves wall assembly and 0.75 inch (20 mm) from the wall. The distance from the floor to the top of the burner shall be 12 inches (300 mm).
5. Procedure.
CWUIC § 11.3.4 High relevance — show source text
CEBC—2025: California Existing Building Code

1.11.3.4, 102.8, 201.3

CFC—2025: California Fire Code

1.11.3.4, 1.11.9, 1.11.10, 102.8, 105.1, 201.3, 202, 402.1.1, 402.1.2, 402.2.1, 402.2.2, 403.2.4, 404.2, 404.4, 404.5, 404.10.3, 606.1, 606.2

CRC—2025: California Residential Code

1.1.7.3.1, 102.8

NFPA National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471

252—2022: Standard on Fire Test of Door Assemblies

504.9

257—2022: Standard on Fire Test for Window and Glass Block Assemblies

504.8

CEC—2025: California Electrical Code

201.3

SFM State of California, Department of Forestry and Fire Protection, Office of the State Fire Marshal, P.O. Box 944246, Sacramento, CA 94246-2460

12-7A-1: Exterior Wall Siding and Sheathing. A fire resistance test standard consisting of a 150 kW intensity direct flame exposure for a 10-minute duration

504.5, 504.9

12-7A-2: Exterior Windows. A fire resistance test standard consisting of a 150 kW intensity direct flame exposure for an 8-minute duration

504.8

12-7A-3: Horizontal Projection Underside. A fire resistance test standard consisting of a 300 kW intensity direct flame exposure for a 10-minute duration

504.3, 504.7, 504.7.1

12-7A-4: Decking. A two-part test consisting of a heat release rate (Part A) deck assembly combustion test with an under deck exposure of 80 kW intensity direct flame for a 3-minute duration, and a (Part B) sustained deck assembly combustion test consisting of a deck upper surface burning ember exposure with a 12 mph wind for 40 minutes using a 2.2 lb (1kg) burning “Class A” size 12" × 12" × 2.25" (300 mm × 300 mm × 57 mm) roof test brand

504.7.3.2

12-7A-4A: Decking Alternate Method A. A heat release rate deck assembly combustion test with an under deck exposure of 80 kW intensity direct flame for a 3-minute duration

504.7.3.2

State Fire Marshal’s Guidelines for Fire Hydrant Markings Along State Highways and Freeways, May 1988

404.8

UL UL LLC, 333 Pfingsten Road, Northbrook, IL 60062-2096

9—2009: Fire Tests of Window Assemblies—with Revisions through March 2020
CWUIC § 12-7 High relevance — show source text
SFM STANDARD 12-7A-3

12-7A-3.1 Application. The minimum design, construction and performance standards set forth herein for the exposed underside of horizontal projections such as the horizontal soffits of roof eaves, floor projections and exposed underfloor areas are those deemed necessary to establish conformance to the provisions of these regulations. Materials and assemblies that meet the performance criteria of this standard are acceptable for use as defined in the California Building Standards Code.

12-7A-3.2 Scope. This standard evaluates the fire-resistive performance of horizontal projection assemblies including the horizontal soffits of roof eaves, floor projections and exposed underfloor areas when subjected to direct flame exposure to the underside of a horizontal projection.

12-7A-3.3 Referenced documents.
1. ASTM D4442, Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials.
2. ASTM D4444, Test Methods for Use and Calibration of Hand-Held Moisture Meters.
3. California Building Code, Chapter 7A.
12-7A-3.4 Definitions.
1. Eaves. A projecting edge of a roof that extends beyond the supporting wall as in CBC 702A “Roof Eave” or similar horizontal projection assembly.
2. Soffit. The enclosed underside of any exterior overhanging section of a roof eave or similar horizontal projection assembly (see CBC 702A “Roof Eave Soffit”).
12-7A-3.5 Equipment.
1. Burner. A 12 by 12-inch (300 by 300 mm) diffusion burner shall be used. Natural gas, methane or propane shall be supplied to the burner through a metered control system. The gas supply to the burner shall produce a net heat output of 300 ± 15 kW throughout the flame exposure. Burner output can be determined from HRR or calculated from the gas flow rate, temperature and pressure.
2. Infrared temperature analyzer (optional). Intended for monitoring the temperature change of the inside of the eaves.
3. Moisture content. Prior to testing, all materials (lumber and soffit material) shall be conditioned to a constant weight or for a minimum of 30 days at 73 ± 4°F (23 ± 2°C) and 50 ± 5% relative humidity, whichever occurs first. Constant weight shall be defined as occurring when the change in test material weight is less than or equal to 2 percent in a 24-hour period. Lumber moisture content shall be between 8 and 12 percent (oven-dry basis) and sheathing shall not exceed 8 percent (oven-dry basis).
12-7A-3.6 Materials.
1. Framing. The materials used shall be representative of the grades that would be typical of eave construction and installed in the eave’s subassembly as per accepted construction practices.
2. Soffit. Material selected for the test.
12-7A-3.7 Test system preparation (Figure 1).
1. Eaves fabrication. The 4-foot-wide by 2-foot (1.2 m by 0.6 m) test specimen shall be constructed to fit into a 4-foot-wide (1.2 m) space at the top of the test assembly described in SFM 12-7A-1.
CWUIC § 504.7.3.3 High relevance — show source text
504.7.3.3 Performance requirements for Section 504.7.3.2, Item 1. Materials shall be tested in accordance with both ASTM E2632 and ASTM E2726 and comply with the conditions of acceptance in Sections 504.7.3.3.1 and 504.7.3.3.2. The material shall also be tested in accordance with ASTM E84 or UL 723 and comply with the performance requirements of Section 503.2.4.

504.7.3.3.1 Conditions of acceptance for ASTM E2632. The ASTM E2632 test shall be conducted on a minimum of three test specimens and meet the conditions of acceptance in Items 1 through 3. If any one of the three tests does not meet the conditions of acceptance, three additional tests shall be performed. All three additional tests must meet the conditions of acceptance. 1. Peak heat release rate of less than or equal to 25 kW/ft2 (269 kW/m2).

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SPECIAL BUILDING CONSTRUCTION REGULATIONS

2. Absence of sustained flaming or glowing combustion of any kind at the conclusion of the 40-minute observation period. 3. Absence of falling particles that are still burning when reaching the burner or floor.

504.7.3.3.2 Conditions of acceptance for ASTM E2726. The ASTM E2726 test shall be conducted, using a “Class A” size roof test brand, on a minimum of three test specimens and meet the conditions of acceptance in Items 1 and 2. If any one of the three tests does not meet the conditions of acceptance, three additional tests shall be performed. All three additional tests must meet the conditions of acceptance. 1. Absence of sustained flaming or glowing combustion of any kind at the conclusion of the 40-minute observation period. 2. Absence of falling particles that are still burning when reaching the burner or floor.

504.7.3.4 Performance requirements for Section 504.7.3.2, Item 7. The ASTM E2632 test shall be conducted on a minimum of three test specimens and the peak heat release rate shall be less than or equal to 25 kW/ft [2] (269 kW/m [2] ). If any one of the three tests does not meet the conditions of acceptance, three additional tests shall be run. All the additional tests shall meet the condi- tion of acceptance. If any one of the three tests does not meet the condition of acceptance, three additional tests shall be performed. All three additional tests must show a peak heat release rate shall be 25 kW/ft2 (269 kW/m2) or less.

504.8 Exterior glazing. Exterior windows, window walls and glazed doors, windows within exterior doors, and skylights shall be constructed of any of the following: 1. Multilayered glazed panels with at least one pane of tempered glass complying with Section 2406 of the California Building Code.

2. Glass block.
CWUIC § 12-7 High relevance — show source text
Note the time elapsed and location of penetration if it occurs. 4. Report. Report a description of the window unit, including the types of frames, cladding and panes being tested and details of the installation. Record when and how the glass breaks or flame-through occurs in the framing materials or sash, and/or

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MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE

if the framing material deforms or otherwise suffers a loss of integrity such that the glass cannot be held in place, and a record of the time at which any of these events occur.

12-7A-2.8 Conditions of Acceptance.
1. Duration of direct flame exposure. To pass this test standard, the window and window assembly shall withstand 8 minutes of direct flame exposure with the absence of flame penetration through the window frame or pane, or structural failure of the window frame or pane.
2. Flame penetration or structural failure. Flame penetration or structural failure of the flame or pane anytime during the test constitutes failure of this test standard.
FIGURE 1 — SCHEMATIC OF THE WALL ASSEMBLY Test Module used for evaluating the fire performance of a window.

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HORIZONTAL PROJECTION UNDERSIDE

SFM STANDARD 12-7A-3

12-7A-3.1 Application. The minimum design, construction and performance standards set forth herein for the exposed underside of horizontal projections such as the horizontal soffits of roof eaves, floor projections and exposed underfloor areas are those deemed necessary to establish conformance to the provisions of these regulations. Materials and assemblies that meet the performance criteria of this standard are acceptable for use as defined in the California Building Standards Code.

12-7A-3.2 Scope. This standard evaluates the fire-resistive performance of horizontal projection assemblies including the horizontal soffits of roof eaves, floor projections and exposed underfloor areas when subjected to direct flame exposure to the underside of a horizontal projection.

12-7A-3.3 Referenced documents.
1. ASTM D4442, Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials.
2. ASTM D4444, Test Methods for Use and Calibration of Hand-Held Moisture Meters.
3. California Building Code, Chapter 7A.
12-7A-3.4 Definitions.
1. Eaves. A projecting edge of a roof that extends beyond the supporting wall as in CBC 702A “Roof Eave” or similar horizontal projection assembly.
2. Soffit. The enclosed underside of any exterior overhanging section of a roof eave or similar horizontal projection assembly (see CBC 702A “Roof Eave Soffit”).
12-7A-3.5 Equipment.
1. Burner. A 12 by 12-inch (300 by 300 mm) diffusion burner shall be used. Natural gas, methane or propane shall be supplied to the burner through a metered control system.
CWUIC § 504.2.1.1 High relevance — show source text
504.2.1.1 Airspace under roof covering. Where the roof covering is installed over a combustible deck and the roofing profile creates an airspace under the roof covering, the installation shall comply with the following: 1. A 72 lb. (32.7 kg) cap sheet complying with ASTM D3909 Standard Specification for “Asphalt Rolled Roofing (Glass Felt) Surfaced with Mineral Granules,” shall be installed over the roof deck.

Exception: Cap sheet is not required where not less than 1 inch of mineral wool board or other noncombustible material is located between the roofing material and wood framing or deck. 2. Bird stops shall be used at the eaves where the profile fits, to prevent the entry of debris at the eave. 3. Hip and ridge caps shall be mudded in to prevent intrusion of fire or embers.

504.2.1.2 Roof underlayment. A listed and labeled roof underlayment that has been tested as part of the roof assembly in accor- dance with ASTM E108 or UL 790 for Class A fire classification shall be installed in accordance with the underlayment manufacturer’s installation instructions and listing. Bird stops shall be used at the eaves when the profile fits, to prevent the entry of debris at the eave. Hip and ridge caps shall be mudded in to prevent intrusion of fire or embers.

Exception: Where the roof sheathing is fire-retardant-treated wood labeled for exterior use and complies with Section 2303.2 of the California Building Code, the underlayment shall not be required to comply with a Class A fire classification.

504.2.2 Roof valleys. Where provided, valley flashings shall be not less than 0.019 inch (0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal installed over a minimum 36-inch-wide (914 mm) underlayment consisting of one layer of 72-pound (32.4 kg) mineral-surfaced, nonperforated cap sheet complying with ASTM D3909 running the full length of the valley.

504.3 Protection of enclosed eaves. The exposed underside of enclosed roof eaves and soffits shall be protected on the exposed underside by one or more of the following:

1. Noncombustible materials.

2. Ignition-resistant building materials. 3. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

4. 2-inch (51 mm) nominal dimension lumber . 5. 1-inch (25 mm) nominal fire-retardant-treated lumber or [3] / 4 -inch (19.1 mm) nominal fire-retardant-treated plywood, identified for exterior use and complying with Section 2303.2 of the California Building Code . 6. Boxed-in roof eave soffit assemblies with an underside that meets the performance criteria in Section 504.7.2 when tested in accordance with the test procedures set forth in ASTM E2957. 7. Boxed-in roof eave soffit assemblies with an underside that meets the performance criteria in accordance with the test proce- dures set forth in SFM Standard 12-7A-3.
CWUIC § 5.3. High relevance — show source text
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5.3. Continued combustion. If penetration does not occur, continue observation for an additional 30 minutes or until all combustion has ceased.

Note: An infrared thermometer has been found to be useful to detect the increase of temperature on the back side of the eaves and as an aid to identify the areas of potential combustion. 6. Observations. Note the time, location and nature of flame penetration.

12-7A-3.9 Report. The report shall include a description of the eaves material, details of the construction of the eaves, moisture content of the framing and wood-based soffit elements as applicable, and point of flame penetration. Provide details on the time and reasons for early termination of the test.

12-7A-3.10 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance.
1. Absence of flame penetration of the eaves or horizontal projection assembly at any time.
2. Absence of structural failure of the eaves or horizontal projection subassembly at any time.
3. Absence of sustained combustion of any kind at the conclusion of the 40-minute test.
FIGURE 1 — EAVES TEST ASSEMBLY

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DECKING

SFM STANDARD 12-7A-4

12-7A-4.1 Application. The minimum design, construction and performance standards set forth herein for unloaded decks are those deemed necessary to establish conformance to the provisions of these regulations. Materials and assemblies that meet the performance criteria of this standard are acceptable for use as defined in California Building Standards Code.

12-7A-4.2 Scope. This standard evaluates the performance of decks (or other horizontal ancillary structures in close proximity to primary structures) when exposed to direct flames and brands. The under-deck flame exposure test is intended to determine the heat release rate (HRR) and degradation modes of deck or other horizontal boards when exposed to a burner flame simulating combustibles beneath a deck. The burning brand exposure test is intended to determine the degradation modes of deck or other horizontal boards when exposed to a burning brand on the upper surface.

12-7A-4.3 Referenced document.
1. ASTM D4444, Test Methods for Use and Calibration of Hand-Held Moisture Meters.
2. ASTM E108, Test Methods for Fire Tests of Roof Coverings.
3. California Building Code, Chapter 7A.
4. UL 790, Standard Test Methods for Fire Tests of Roof Coverings.
12-7A-4.4 Definitions.
1. Deck boards. Horizontal members that constitute the exposed surface of the ancillary structure.
2. Deck surface area. The test specimen area defined by the overall specimen length and width after assembly.
3. Heat release rate. The net rate of energy release as measured by oxygen depletion calorimetry.
**12-7A-4.5 Test assembly.

CWUIC § 304.8 High relevance — show source text

The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave overhang if fireblocking is provided from the wall top plate to the underside
of the roof sheathing.
b. The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the rake overhang where vent openings that communicate with the attic are not
installed in the overhang or gable wall.|For SI: 1 foot = 304.8 mm.
NA = Not Applicable.
a. The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave overhang if fireblocking is provided from the wall top plate to the underside
of the roof sheathing.
b. The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the rake overhang where vent openings that communicate with the attic are not
installed in the overhang or gable wall.|

TABLE R302.1(2)—EXTERIOR WALLS—DWELLINGS, TOWNHOUSES AND ACCESSORY BUILDINGS WITH AUTOMATIC RESIDENTIAL FIRE SPRINKLER PROTECTION	Col2	Col3	Col4
EXTERIOR WALL ELEMENT	EXTERIOR WALL ELEMENT	MINIMUM FIRE-RESISTANCE RATING	MINIMUM FIRE SEPARATION DISTANCE
Walls	Fire-resistance rated	1 hour—tested in accordance with ASTM E119, UL 263 or Section 703.2.2 of the_California Building Code_ with exposure from the outside	0 feet
Walls	Not fire-resistance rated	0 hours	3 feeta
Projections	Not allowed	NA	< 2 feet
Projections	Fire-resistance rated	1 hour on the underside, or heavy timber, or fire-retardant-treated woodb, c	2 feeta
Projections	Not fire-resistance rated	0 hours	3 feet
Openings in walls	Not allowed	NA	< 3 feet
Openings in walls	Unlimited	0 hours	3 feeta
Penetrations	All	Comply with Section R302.4	< 3 feet
Penetrations	All	None required	3 feeta
For SI: 1 foot = 304.8 mm. NA = Not Applicable. a. For residential subdivisions where all dwellings and townhouses are equipped throughout with an automatic sprinkler system installed in accordance with Section_R309_, the fire separation distance for exterior walls not fire-resistance rated and for fire-resistance-rated projections shall be permitted to be reduced to 0 feet, and unlimited unprotected openings and penetrations shall be permitted, where the adjoining lot provides an open setback yard that is 6 feet or more in width on the opposite side of the property line. b. The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave overhang if fireblocking is provided from the wall top plate to the underside of the roof sheathing. c. The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the rake overhang where vent openings that communicate with the attic are not installed in the overhang or gable wall.	For SI: 1 foot = 304.8 mm. NA = Not Applicable. a.

Frequently asked questions

What exactly is being tested by SFM 12‑7A‑3?

SFM 12‑7A‑3 subjects the exposed underside of a horizontal projection (soffit/eave/floor projection) to a controlled direct flame from an underlying burner to evaluate flame penetration, structural failure and sustained combustion; it defines specimen size, burner output and acceptance criteria.

Can I use ASTM E2957 instead of SFM 12‑7A‑3?

Yes. The CWUIC explicitly allows boxed‑in eave/soffit assemblies to meet performance criteria either by ASTM E2957 or SFM 12‑7A‑3, as referenced in § 504.3 and § 504.7.1. Always follow the exact procedure called out.

How many tests must pass for acceptance?

Run three replicate tests. If one of the three fails, you must run three additional tests; all three additional tests must pass for acceptance. § 504.7.2 and SFM 12‑7A‑3 specify this protocol.

What’s the critical burner power and exposure time for soffit/eave underside tests?

Use a 12" × 12" diffusion burner producing 300 ± 15 kW and maintain 10 minutes of direct flame exposure, with observation continued as required by the standard (up to 40 minutes per acceptance language). SFM 12‑7A‑3 and § 504.7.2.

Are decks tested the same way as soffits?

No. Deck under‑deck tests are in SFM 12‑7A‑4 / 12‑7A‑4A with different heat flux / burner intensities (e.g., 80 ± 4 kW under‑deck exposure in some deck test parts and brand exposure tests). Do not conflate the two standards.

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