Eaves, Soffits, Gutters, Underfloor Protection and Vents

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

• CWUIC § 5.2.2 High relevance — show source text

  5.2.2_||||||| |504|Ignition-resistant
  construction|Y||704A||||||| |504.1|General|Y||705A.1||||||| |504.2|Roof assembly|Y||705A.2
  1505.2||||||| |504.2.1|Roof covering voids|Y||705A.2||||||| |504.2.1.1|Airspace under roof
  covering|Y||705A.2.1||||||| |504.2.1.2|Roof underlayment|Y||705A.2.2||||||| |504.2.2|Roof valleys|Y||705A.3||||||| |504.3|Protection of
  enclosed eaves|Y||707A.6||||||| |504.3.1|Protection of open
  eaves|Y||707A.5||||||| |504.4|Gutters and
  downspouts|Y||705A.4||||||| |504.5|Exterior walls|Y||707A.4||||||| |504.5.1|Flashing|Y|504.5.1|||||||| |504.5.2|Exterior wall covering|Y||707A.3
  704A.4 #3||||||| |504.5.2.1|Extent of exterior wall
  covering|Y||707A.3.1||||||| |504.6|Underfloor enclosure|Y||707A.9||||||| |504.7|Projections|Y||707A.8||||||| |504.7.1|Underside of
  projections|Y||707A.9,
  707A.10||||||| |504.7.2|Conditions of accep-
  tance for ASTM E2957|Y||707A.11||||||| |504.7.3|Decks|Y||709A.1||||||| |504.7.3.1|Flashing|Y||709A.1.1||||||| |504.7.3.2|Decking surfaces|Y||709A.3||||||| |504.7.3.3|Performance require-
  ments for Section
  504.7.3.2, Item 1|Y||709A.4.2||||||| |504.7.3.3.1|Conditions of accep-
  tance for ASTM E2632|Y||709A.4.1||||||| |504.7.3.3.2|Conditions of accep-
  tance for ASTM E2726|Y||709A.4.2||||||| |504.7.3.4|Performance require-
  ments for Section
  504.7.3.2, Item 7|Y||709A.5||||||| |504.8|Exterior glazing|Y||708A.2.1||||||| |504.8.1|Structural glass
  veneer|Y||708A.2.2||||||| |504.8.2|Operable skylights|Y||708A.2.3||||||| |504.9|Exterior doors|Y||708A.3|||||||

• CWUIC § 504.7 High relevance — show source text

  Ignition Source Control Appendix A, A104 Ignition-Resistant Building Material 202, 503 Ignition-Resistant Construction 504 Appendages 504.7 Detached accessory structures 504.11 Eaves 504.3

  Exterior doors 504.9

  Exterior walls 504.5

  Gutters and downspouts 504.4 Protection of eaves 504.3 Roof covering 504.2 Underfloor protection 504.6 Vents 504.10

  Windows 504.8 Ignition-Resistant Construction and Material 503 Inspection and Enforcement 109 Abatement 109.3.8 Authority to inspect 109.1.2 Citations 109.3.4

  Enforcement 109.2 Placarding 109.3.5.3 Prosecution 109.3.6

  Reinspections 109.1.3 Right of entry 104.4 Testing 109.1.4 Unsafe conditions 109.3.5

  Key Box 403.1

  Land Use Limitations Appendix A, A108 Legal Defense of the Code Official 104.8.1 Liability of the Code Official 104.8

  Log Wall Construction 202 LP-Gas Installations 606

  Maintenance 101.6 Maintenance of Defensible Space 604 Modified area 604.2 Responsibility 604.3 Trees 604.4 Mapping of Wildland-Urban Interface Area 302.2 Multilayered Glazed Panels 202

  Noncombustible Roof Covering 202

  Outbuilding 202

  Peer Review 104.2.2.7, 202 Permits

  Application 105.4 Approval 105.5 Expiration 105.8 Issuance 105.6 Preliminary inspection 105.4.1 Refusal to issue 105.6.1

  Required 105.2 Retention 105.9

  Revocation 105.10 Validity 105.7 Work exempt from permit 105.3 Placarding as Unsafe 109.3.5.3 Powers and Duties of the Code

  Official 104.1

  Practical Difficulties 104.2.3 Protection of Pumps and Water Storage Facilities Appendix A, A107

  Rafter Tail 202 Referenced Standards 102.4, Chapter 7 Registered Design Professional 104.2.1.2, 104.2.2.6.2, 106.1, 202 Residential Unit 202 Retroactivity 101.4 Ridgelline 202 Road 202 Roof Covering 202 Roof Covering System 202 Roof Coverings, Replacement or Repair of 507

  Roof Deck 202

  Scope 101 Self-Defense Mechanism Appendix G Service Utilities 111

  Slope 202 Spark Arrestors 605 Stop Work Order 113 Storage of Firewood and Combustible Materials 607 Strategic Ridgeline 202 Structure 202

  Subdivision 202

• CWUIC § 1.5 High relevance — show source text

  2025 CWUIC—continued	Col2	Adopted Yes/No	IWUIC Section	CBC Section	CFC Section	Title 14, Division 1.5 Section	Title 19, Division 1 Section	Gov Code Section	PRC Section	HSC Section
  Section	Title	Title	Title	Title	Title	Title	Title	Title	Title	Title
  Chapter 5	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations
  503.2.4.3.3	Plastic lumber materials	Y		703A.6
  503.2.5	Surface treatment protection	Y		703A.5.3
  503.3	Standards of quality	Y		703A.1
  503.3.1	Qualification by testing	Y		703A.2
  503.3.2	Approved agency	Y		703A.3
  503.3.3	Labeling	Y		703A.4
  503.3.4	Fire-retardant- treated wood shin- gles and shakes	Y		703A.5.2.2
  504	Ignition-resistant construction	Y		704A
  504.1	General	Y		705A.1
  504.2	Roof assembly	Y		705A.2 1505.2
  504.2.1	Roof covering voids	Y		705A.2
  504.2.1.1	Airspace under roof covering	Y		705A.2.1
  504.2.1.2	Roof underlayment	Y		705A.2.2
  504.2.2	Roof valleys	Y		705A.3
  504.3	Protection of enclosed eaves	Y		707A.6
  504.3.1	Protection of open eaves	Y		707A.5
  504.4	Gutters and downspouts	Y		705A.4
  504.5	Exterior walls	Y		707A.4
  504.5.1	Flashing	Y	504.5.1
  504.5.2	Exterior wall covering	Y		707A.3 704A.4 #3
  504.5.2.1	Extent of exterior wall covering	Y		707A.3.1
  504.6	Underfloor enclosure	Y		707A.9
  504.

• 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.
• California Wildland-Urban Interface Code High relevance — show source text

  600
  |87 300
  |169 000
  | |20
  |1280
  |2560
  |4610
  |7990
  |12 100
  |21 700
  |60 000
  |116 000
  | |30
  |1030
  |2050
  |3710
  |6420
  |9690
  |17 400
  |48 200
  |93 200
  | |40
  |878
  |1760
  |3170
  |5490
  |8300
  |14 900
  |41 200
  |79 700
  | |50
  |778
  |1560
  |2810
  |4870
  |7350
  |13 200
  |36 600
  |70 700
  | |60
  |705
  |1410
  |2550
  |4410
  |6660
  |12 000
  |33 100
  |64 000
  | |70
  |649
  |1300
  |2340
  |4060
  |6130
  |11 000
  |30 500
  |58 900
  | |80
  |603
  |1210
  |2180
  |3780
  |5700
  |10 200
  |28 300
  |54 800
  | |90
  |566
  |1130
  |2050
  |3540
  |5350
  |9610
  |26 600
  |51 400
  | |100
  |535
  |1070
  |1930
  |3350
  |5050
  |9080
  |25 100
  |48 600
  | |125
  |474
  |949
  |1710
  |2970
  |4480
  |8050
  |22 300
  |43 000
  | |150
  |429
  |860
  |1550
  |2690
  |4060
  |7290
  |20 200
  |39 000
  | |175
  |395
  |791
  |1430
  |2470
  |3730
  |6710
  |18 600
  |35 900
  | |200
  |368
  |736
  |1330
  |2300
  |3470
  |6240
  |17 300
  |33 400
  | |250
  |326
  |652
  |1180
  |2040
  |3080
  |5530
  |15 300
  |29 600
  | |300
  |295
  |591
  |1070
  |1850
  |2790
  |5010
  |13 900
  |26 800
  | |350
  |272
  |544
  |981
  |1700
  |2570
  |4610
  |12 800
  |24 700
  | |400
  |253
  |506
  |913
  |1580
  |2390
  |4290
  |11 900
  |22 900
  | |450
  |237
  |475
  |856
  |1480
  |2240
  |4020
  |11 100
  |21 500
  | |500
  |224
  |448
  |809
  |1400
  |2120
  |3800
  |10 500
  |20 300
  | |550
  |213
  |426
  |768
  |1330
  |2010
  |3610
  |9990
  |19

• 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

  2025 CALIFORNIA REFERENCED STANDARDS CODE 41

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

  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.

  42 2025 CALIFORNIA REFERENCED STANDARDS CODE

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

  MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE

  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 § 504.3 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.

  2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 5-5

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

  �

  �

  �

  �

  �

  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.

• California Wildland-Urban Interface Code High relevance — show source text

  500
  |25 500
  | |125
  |168
  |352
  |663
  |1360
  |2040
  |3930
  |6260
  |11 100
  |22 600
  | |150
  |153
  |319
  |601
  |1230
  |1850
  |3560
  |5670
  |10 000
  |20 500
  | |175
  |140
  |293
  |553
  |1140
  |1700
  |3270
  |5220
  |9230
  |18 800
  | |200
  |131
  |273
  |514
  |1056
  |1580
  |3050
  |4860
  |8580
  |17 500
  | |250
  |116
  |242
  |456
  |936
  |1400
  |2700
  |4300
  |7610
  |15 500
  | |300
  |105
  |219
  |413
  |848
  |1270
  |2450
  |3900
  |6890
  |14 100
  | |350
  |96
  |202
  |380
  |780
  |1170
  |2250
  |3590
  |6340
  |12 900
  | |400
  |90
  |188
  |353
  |726
  |1090
  |2090
  |3340
  |5900
  |12 000
  | |450
  |84
  |176
  |332
  |681
  |1020
  |1960
  |3130
  |5540
  |11 300
  | |500
  |80
  |166
  |313
  |643
  |964
  |1860
  |2960
  |5230
  |10 700
  | |550
  |76
  |158
  |297
  |611
  |915
  |1760
  |2810
  |4970
  |10 100
  | |600
  |72
  |151
  |284
  |583
  |873
  |1680
  |2680
  |4740
  |9660
  | |650
  |69
  |144
  |272
  |558
  |836
  |1610
  |2570
  |4540
  |9250
  | |700
  |66
  |139
  |261
  |536
  |803
  |1550
  |2470
  |4360
  |8890
  | |750
  |64
  |134
  |252
  |516
  |774
  |1490
  |2380
  |4200
  |8560
  | |800
  |62
  |129<

• CWUIC § 714.3 High relevance — show source text

  714.3 Sleeves. Where sleeves are used, they shall be securely fastened to the assembly penetrated and installed in accordance with the sleeve manufacturer’s installation instructions. Where listed systems are used, the sleeve shall be installed in accordance with the listing criteria for the system. The space between the item contained in the sleeve and the sleeve itself and any space between the sleeve and the assembly penetrated shall be protected in accordance with this section. Insulation and coverings on or in the penetrating item shall not penetrate the assembly unless the specific material used has been tested as part of the assembly in accordance with this section.

  714.4 Fire-resistance-rated walls. Penetrations into or through fire walls, fire barriers, smoke barrier walls and fire partitions shall comply with Sections 714.4.1 through 714.4.3. Penetrations in smoke barrier walls shall also comply with Section 714.5.4.

  714.4.1 Through penetrations. Through penetrations of fire-resistance-rated walls shall comply with Section 714.4.1.1 or 714.4.1.2.

  Exception: Where the penetrating items are steel, ferrous or copper pipes, tubes or conduits, the annular space between the penetrating item and the fire-resistance-rated wall is permitted to be protected by either of the following measures:

  1. In concrete or masonry walls where the penetrating item is a maximum 6-inch (152 mm) nominal diameter and the area of the opening through the wall does not exceed 144 square inches (0.0929 m [2] ), concrete, grout or mortar is permitted where installed the full thickness of the wall or the thickness required to maintain the fire-resistance rating.
  2. The material used to fill the annular space shall prevent the passage of flame and hot gases sufficient to ignite cotton waste when subjected to ASTM E119 or UL 263 time-temperature fire conditions under a minimum positive pressure

  2025 CALIFORNIA BUILDING CODE 7-23

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

  FIRE AND SMOKE PROTECTION FEATURES

  differential of 0.01 inch of water (2.49 Pa) at the location of the penetration for the time period equivalent to the fireresistance rating of the construction penetrated.

  714.4.1.1 Fire-resistance-rated assemblies. Through penetrations shall be protected using systems installed as tested in the approved fire-resistance-rated assembly.

  714.4.1.2 Through-penetration firestop system. Through penetrations shall be protected by an approved penetration firestop system installed as tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water (2.49 Pa) and shall have an F rating of not less than the required fire-resistance rating of the wall penetrated.

  714.4.2 Membrane penetrations. Membrane penetrations shall comply with Section 714.4.1. Where walls or partitions are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.

  Exceptions: 1.

• CWUIC § 2.1 High relevance — show source text

  G101.2.1 Home-hardening features. If homes are not already provided with the suggested protection, the following items should be considered in hardening a home against wildfire. 1. When it is time to replace your roof, replace it with roof assembly classified as Class A when tested in accordance with ASTM E108 or UL 790.

  2. Block any spaces at the eaves between your roof covering and sheathing with noncombustible materials (bird stops). 3. Install a noncombustible rain gutter and downspouts. Install rain gutter covers to prevent the accumulation of leaves and debris in the gutters. 4. Cover your chimney and stovepipe outlets with a noncombustible, corrosion-resistant metal mesh screen (spark arrestor), with [3] / 8 -inch (9.5 mm) to [1] / 2 -inch (12.7 mm) openings. 5. Install ember- and flame-resistant vents. Choose products that have been approved and labeled as OSFM Wildland-Urban Interface (WUI) Products. A temporary solution is to cover the vent openings with a noncombustible and corrosion-resistant mesh with [1] / 16 -inch (1.6 mm) to [1] / 8 -inch (3.2 mm) openings. 6. Caulk and plug gaps greater than [1] / 8 inch (3.2 mm) around exposed rafters and blocking to prevent ember intrusion into the attic or other enclosed spaces. 7. Inspect exterior siding for dry rot, gaps, cracks and warping. Caulk or plug gaps greater than [1] / 8 inch (3.2 mm) in siding and replace any damaged boards, including those with dry rot. 8. Install weather stripping to fill gaps greater than [1] / 8 inch (3.2 mm) between garage doors and door frames to prevent ember intrusion. The weather stripping must be compliant with UL Standard 10C. 9. When it’s time to replace your windows, replace them with multipaned windows that have at least one pane of tempered glass. Choose products that have been approved and labeled as OSFM Wildland-Urban Interface (WUI) Products. 10. When it’s time to replace your siding or deck, use noncombustible, ignition-resistant, or other OSFM-approved Wildland- Urban Interface (WUI) Products. 11. Cover openings to operable skylights with noncombustible metal mesh screen with openings in the screen not to exceed [1] / 8 inch (3.2 mm). 12. Install a minimum 6-inch metal flashing, applied vertically on the exterior of the wall at the deck-to-wall intersection to protect the combustible siding material. 13. _Enclose openings beneath decks or cantilevered construction with one of the materials required in Section 504.5.

• CWUIC § 5-1 Medium relevance — show source text

  2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 5-1

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

  5-2 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE

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

  5 SPECIAL BUILDING CONSTRUCTION REGULATIONS

  User notes:

  About this chapter: Chapter 5 provides regulations that establish minimum standards for the location, design and construction of buildings and structures based on construction within a Fire Hazard Severity Zone or a Wildland-Urban Interface (WUI) Area.

  The construction provisions of Chapter 5 are intended to supplement the requirements of the California Building Code and California Residential Code and address mitigation of the unique hazards posed to buildings by wildfire and to reduce the hazards of building fires spreading to wildland fuels. This is accomplished by requiring ignition-resistant construction materials. Construction features regulated include underfloor areas; roof coverings; eaves and soffits; gutters and downspouts; exterior walls, doors and windows; ventilation openings and accessory structures.

  SECTION 501—GENERAL

  501.1 Scope. Buildings and structures in a wildland-urban interface area shall be constructed in accordance with the California Build- ing Code and this code.

  Exceptions:

  1. Group U accessory structures not exceeding 120 square feet (11 m [2] ) in floor area where located not less than 50 feet (15 240 mm) from applicable buildings.
  2. Group U agricultural buildings not less than 50 feet (15 240 mm) from applicable buildings.

  501.2 Objective. The objective of this chapter is to establish minimum standards to locate, design and construct buildings and structures or portions thereof for the protection of life and property, to resist damage from wildfires, and to mitigate building and structure fires from spreading to wildland fuels.

  501.3 Fire-resistance-rated construction. Where this code requires 1-hour fire-resistance-rated construction, the fire-resistance rating of building elements, components or assemblies shall be determined in accordance with the test procedures set forth in ASTM E119 or UL 263.

  Exceptions:

  1. The fire-resistance rating of building elements, components or assemblies based on the prescriptive designs prescribed in Section 721 of the California Building Code .
  2. The fire-resistance rating of building elements, components or assemblies based on the calculation procedures in accordance with Section 722 of the California Building Code .

  501.4 Noncombustibility tests. The tests indicated in Section 501.4.1 shall serve as criteria for acceptance of noncombustible building materials. The term “noncombustible” does not apply to the flame spread characteristics of interior finish or trim materials. A material shall not be classified as a noncombustible building construction material if it is subject to an increase in combustibility or flame spread beyond the limitations herein established through the effects of age, moisture or other atmospheric conditions.

  501.4.1 Noncombustible materials. Materials required to be noncombustible shall be tested in accordance with ASTM E136 and pass the test. Alternately, materials required to be noncombustible shall be tested in accordance with ASTM E2652 using the accep- tance criteria prescribed by ASTM E136.

• CWUIC § 2.1 Medium relevance — show source text

  This appendix is for informational purposes and is not intended for adoption.

  User notes:

  About this appendix: Appendix G is an information appendix that provides discussion of some elements of the proposed self-defense mechanisms and their role in enhancing the protection of exposed structures in the wildland-urban interface. The items provided in this appendix provide owners with suggestions for increasing the survivability of their structure. These items are not mandatory but can be considered by owners to increase the safety of structures.

  SECTION G101—GENERAL

  G101.1 Identification of the problem. The California Wildland-Urban Interface Code establishes a set of minimum standards to reduce the loss of property from wildfire. The purpose of these standards is to prevent wildfire spreading from vegetation to a building. Many homes were built in the wildland-urban interface areas prior to the implementation of provisions found in this code. As a result, many homes are lacking in their ability to survive an approaching wildfire. Many of the features discussed in this appendix are designed as low- cost features to retrofit existing homes. Additionally, recommendations are provided beyond the minimum code requirements for those homeowners who desire to increase the survivability of their home. This appendix chapter provides a discussion of some possible self- defense features to enhance survivability and harden the structure against an approaching wildfire.

  G101.2 Structural survivability. The home-hardening features listed in Section G101.2.1 were developed as a best practices guide to assist homeowners in increasing the ignition resistance of their homes from wildfires. Some of these items are based on upgrading to more stringent building materials when that building component is due for replacement as part of its normal maintenance or lifespan, such as the roof covering.

  G101.2.1 Home-hardening features. If homes are not already provided with the suggested protection, the following items should be considered in hardening a home against wildfire. 1. When it is time to replace your roof, replace it with roof assembly classified as Class A when tested in accordance with ASTM E108 or UL 790.

  2. Block any spaces at the eaves between your roof covering and sheathing with noncombustible materials (bird stops). 3. Install a noncombustible rain gutter and downspouts. Install rain gutter covers to prevent the accumulation of leaves and debris in the gutters. 4. Cover your chimney and stovepipe outlets with a noncombustible, corrosion-resistant metal mesh screen (spark arrestor), with [3] / 8 -inch (9.5 mm) to [1] / 2 -inch (12.7 mm) openings. 5. Install ember- and flame-resistant vents. Choose products that have been approved and labeled as OSFM Wildland-Urban Interface (WUI) Products. A temporary solution is to cover the vent openings with a noncombustible and corrosion-resistant mesh with [1] / 16 -inch (1.6 mm) to [1] / 8 -inch (3.2 mm) openings. 6. Caulk and plug gaps greater than [1] / 8 inch (3.2 mm) around exposed rafters and blocking to prevent ember intrusion into the attic or other enclosed spaces. 7. _Inspect exterior siding for dry rot, gaps, cracks and warping.