CRC · California Residential Code

What listing, labeling and installation requirements apply to factory-built fireplaces and chimneys?

Factory-built fireplaces and chimneys must carry a listing/label and be installed exactly per that listing and the manufacturer’s instructions (for example, factory-built fireplaces tested to UL 127 and chimneys listed and marked as required). Follow the product’s listing for clearances, hearth extensions, doors, shrouds, offsets and insulation shields — the listing and the manufacturer control the installation.

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

Factory-built fireplaces and factory-built chimneys must be listed and labeled and installed exactly per their listing and the manufacturer’s installation instructions. The California Residential Code makes this explicit for factory-built fireplaces in § R1004.1 and for factory-built chimneys in § R1005.1. These listings also identify the required test standards (for example, UL 127 for factory-built fireplaces and specified UL standards for chimneys). § R1004.1 and § R1005.1

The single most important rule: install only factory-built fireplaces and chimneys that are listed and labeled and follow the exact conditions of that listing and the manufacturer’s installation instructions. § R1004.1 § R1005.1

Requirements in detail

Basic listing and labeling requirement

  • A factory-built fireplace must be listed and labeled and installed in accordance with the conditions of the listing; factory-built fireplaces are tested in accordance with UL 127. § R1004.1
  • A factory-built chimney must be listed and labeled and installed and terminated in accordance with the manufacturer’s installation instructions (i.e., the conditions of the listing). § R1005.1

Additional, frequently applicable rules (decision-relevant items)

Use the table below to quickly decide which standard or limitation applies.

Decision dimension / value Requirement (plain English) Code Reference
Listing & labeling required? Yes — both fireplaces and chimneys must be listed and labeled and installed per listing/manufacturer instructions. § R1004.1; § R1005.1
Test standard — factory-built fireplaces Must be tested in accordance with UL 127. § R1004.1
Hearth extension standard Listed hearth extensions must comply with UL 1618 and be installed per the fireplace listing. § R1004.2
Gasketed fireplace doors Prohibited unless the fireplace system has been specifically tested, listed and labeled for gasketed doors (UL 127 test). § R1004.5
Decorative shrouds at termination Not allowed unless the shroud is listed and labeled for that specific factory-built system and installed per manufacturer instructions. § R1004.3; § R1005.2
Chimney use with solid-fuel appliances Chimneys for solid fuel in dwelling units must meet Type HT requirements of UL 103 and be marked “Type HT” and “Residential Type and Building Heating Appliance Chimney.” § R1005.3
Chimneys for factory-built fireplaces Chimneys used with factory-built fireplaces must comply with UL 127. § R1005.4
Medium-heat appliances (>1,000°F at chimney entrance) Chimneys serving these appliances must comply with UL 959. Threshold = >1,000°F (538°C) measured at chimney entrance. § R1005.6
Chimney offsets / elbows No part of the chimney may be angled more than 30° from vertical; the assembly may not include more than four elbows. § R1005.7; § R1005.9
Insulation shield through insulated assemblies Where a factory-built chimney passes through insulation, install an insulation shield of steel ≥ 0.0187 inch (No. 26 gauge); maintain the manufacturer-specified clearance to combustibles; where passing through attic insulation shield must end ≥ 2 inches above insulation. § R1005.8

Notes on the table:

  • The listing / label is authoritative: it typically contains clear clearance-to-combustible dimensions, hearth requirements, termination caps allowed, and other system-specific installation limits — follow the listing and manufacturer instructions exactly rather than guessing from generic values. § R1004.1 § R1005.1

Installation control points to check on every job

  • Verify the appliance or fireplace has a label showing the listing and the UL standard (e.g., UL 127). § R1004.1
  • Confirm the chimney listing and applicable UL standard (UL 103, UL 959, UL 2561 as referenced in related mechanical code sections) and required marking (for Type HT). § R1005.1; § R1005.3
  • Follow manufacturer’s instructions for clearances, hearth extension installation, exterior combustion air components (if listed), termination components, and any required insulation shields. § R1004.2; § R1006.1.1

Exceptions & special cases

  • Gasketed doors: A gasketed fireplace door is normally prohibited on factory-built fireplaces unless the entire fireplace system (including the door assembly) has been specifically tested, listed and labeled for that configuration in accordance with UL 127. § R1004.5
  • Decorative shrouds: Allowed only when the shroud itself is listed and labeled for use with that specific factory-built fireplace or chimney system, and then must be installed per the manufacturer. § R1004.3; § R1005.2
  • Solid-fuel appliances: Chimney requirements are stricter for solid-fuel appliances — chimneys in dwelling units must meet Type HT of UL 103 and be appropriately marked. § R1005.3

If a specific installation detail is not covered by the fireplace or chimney manufacturer’s instructions, the code’s fallback limits (e.g., 30° offset max or four elbows) apply per § R1005.7 / R1005.9.

Common mistakes

  • Installing an unlisted or unlabeled component and assuming “close enough” compliance — the code requires listed and labeled systems; the label and listing control. § R1004.1; § R1005.1
  • Adding aftermarket parts (gasketed doors, decorative shrouds, termination caps) that are not listed for that specific system, or installing them contrary to the system listing. § R1004.5; § R1004.3; § R1005.2
  • Ignoring the listing’s specified clearances to combustibles and instead using typical or assumed clearances — the listing may be more or less restrictive than another product. § R1004.1
  • Over‑offsetting chimneys or using too many elbows (more than four elbows or angles > 30°). § R1005.7; § R1005.9

Worked example — concrete scenario

Scenario: You are installing a factory-built wood-burning fireplace (listed system) in a California dwelling. The job requires running a factory-built chimney to the roof with one offset.

Steps and code checks:

  1. Confirm the fireplace unit is listed and labeled and tested to UL 127 (look on the fireplace label). This is required by § R1004.1.
  2. Check the manufacturer’s installation instructions and the listing for the required hearth extension. If a listed hearth extension is provided, it must comply with UL 1618 and be installed per the listing. § R1004.2
  3. Chimney selection: because this is a factory-built fireplace, the chimney must comply with UL 127 for chimneys serving factory-built fireplaces (see § R1005.4) and be listed and labeled for that appliance; install and terminate per the chimney manufacturer’s instructions and the chimney listing. § R1005.1; § R1005.4
  4. Offsets: if the chimney includes a single offset, ensure that no part of the chimney is angled more than 30° from vertical. If your offset piece is 25°, it is acceptable; a 45° elbow would violate § R1005.7. Also verify you will not exceed four elbows in the assembly. § R1005.7
  5. Insulation shield: if the chimney passes through insulated attic space, install the manufacturer-prescribed insulation shield or, where an independent shield is required, use steel ≥ 0.0187 inch (No. 26 gauge) and terminate it at least 2 inches above the insulation. § R1005.8

If all of the above checks pass and the installation is per the listing/instructions, the installation meets the listing/labeling requirements in § R1004.1 and § R1005.1.

Related provisions

  • § R1004.2 — Hearth extensions; listed hearth extensions and UL 1618.
  • § R1004.3 — Decorative shrouds for factory-built fireplaces (listed & labeled requirement).
  • § R1004.5 — Gasketed fireplace doors restriction unless system tested/listed.
  • § R1005.2 — Decorative shrouds at chimney termination.
  • § R1005.3 — Chimney marking and Type HT requirements for solid‑fuel appliances (UL 103).
  • § R1005.4 — Chimneys for factory-built fireplaces must comply with UL 127.
  • § R1005.6 — Medium‑heat appliance chimney requirements (UL 959; threshold > 1,000°F).
  • § R1005.7 / § R1005.9 — Chimney offsets: max 30° and no more than four elbows.
  • § R1005.8 — Insulation shield thickness 0.0187 in (No. 26 gage) and attic termination ≥ 2 in above insulation.
  • § R1006.1.1 — Exterior combustion air ducts for factory-built fireplaces: must be a listed component and installed per manufacturer instructions.

(If you need the exact label wording, the listing report, or the manufacturer’s installation manual, obtain the product’s listing document and the installation instructions; the code requires following those documents verbatim. § R1004.1; § R1005.1.)

Code references

Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:

  • CRC § 25.4 High relevance — show source text

    FIGURE R1003.20—CHIMNEY CRICKET

    AIRSPACE

    ROOF LINE

    For SI: 1 inch = 25.4 mm.

    FLUE LINER Col2 Col3 Col4 Col5
    1 IN.
    AIRS    		 1 IN.
    AIRS    		 1 IN.
    AIRS    		 1 IN.
    AIRS    		 1 IN.
    AIRS
    W W W W W

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    �

    CHIMNEYS AND FIREPLACES

    SECTION R1004—FACTORY-BUILT FIREPLACES

    R1004.1 General. Factory-built fireplaces shall be listed and labeled and shall be installed in accordance with the conditions of the listing. Factory-built fireplaces shall be tested in accordance with UL 127.

    R1004.1.1 Factory-built wood burning fireplaces. Factory-built wood burning fireplaces shall be qualified at the U.S. EPA’s Volun- tary Fireplace Program Phase 2 emissions level and be in accordance with the California Green Building Standards Code, Chapter 4, Division 4.5.

    R1004.2 Hearth extensions. Hearth extensions of approved factory-built fireplaces shall be installed in accordance with the listing of the fireplace. The hearth extension shall be readily distinguishable from the surrounding floor area. Listed and labeled hearth extensions shall comply with UL 1618.

    R1004.3 Decorative shrouds. Decorative shrouds shall not be installed at the termination of chimneys for factory-built fireplaces except where the shrouds are listed and labeled for use with the specific factory-built fireplace system and installed in accordance with the manufacturer’s instructions.

    R1004.5 Gasketed fireplace doors. A gasketed fireplace door shall not be installed on a factory-built fireplace except where the fireplace system has been specifically tested, listed and labeled for such use in accordance with UL 127.

    SECTION R1005—FACTORY-BUILT CHIMNEYS

    R1005.1 Listing. Factory-built chimneys shall be listed and labeled and shall be installed and terminated in accordance with the manufacturer’s installation instructions.

    R1005.2 Decorative shrouds. Decorative shrouds shall not be installed at the termination of factory-built chimneys except where the shrouds are listed and labeled for use with the specific factory-built chimney system and installed in accordance with the manufacturer’s installation instructions.

    R1005.3 Solid-fuel appliances. Factory-built chimneys installed in dwelling units with solid-fuel-burning appliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential Type and Building Heating Appliance Chimney.”

    Exception: Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 and shall be marked “Residential Type and Building Heating Appliance Chimney.”

    Chimneys for use with open combustion chamber appliances installed in buildings other than dwelling units shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” or “Residential Type and Building Heating Appliance Chimney.”

    R1005.4 Factory-built fireplaces. Chimneys for use with factory-built fireplaces shall comply with the requirements of UL 127.

  • CRC § 802.5.1 High relevance — show source text

    802.5.1 Factory-Built Chimneys. Factory-built chimneys shall be listed in accordance with UL 103, UL 959, or UL 2561. Factory-built chimneys used to vent appliances that operate at positive vent pressure shall be listed for such application. [NFPA 54:12.6.1.1]

    802.5.1.1 Decorative Shrouds. Decorative shrouds addressed in Section 802.5.4.3 shall comply with UL 103 for factory-built residential chimneys, UL 127 for factory-built fireplaces, or UL 1482 for solid-fuel room heaters.

    802.5.2 Metal Chimneys. Metal chimneys shall be built and installed in accordance with NFPA 211. [NFPA 54:12.6.1.2]

    802.5.3 Masonry Chimneys. Masonry chimneys shall be built and installed in accordance with NFPA 211 and lined with one of the following:

    (1) Approved clay flue lining.

    (2) A chimney lining system listed and labeled in accordance with UL 1777.

    (3) Other approved material that resists corrosion, erosion, softening, or cracking from vent gases at temperatures up to 1800°F (982°C).

    Exception: Masonry chimney flues lined with a chimney lining system specifically listed for use with listed appliances with draft hoods, Category I appliances, and

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    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    CHIMNEYS AND VENTS

    TABLE 802.4

    TYPE OF VENTING SYSTEM TO BE USED

    [NFPA 54: TABLE 12.5.1]

    APPLIANCES TYPE OF VENTING SYSTEM LOCATION OF REQUIREMENTS
    Listed Category I appliances
    Listed appliances equipped with draft hood
    Appliances listed for use with Type B gas vent    		 Type B gas vent Section 802.6
    Listed Category I appliances
    Listed appliances equipped with draft hood
    Appliances listed for use with Type B gas vent    		 Chimney Section 802.5
    Listed Category I appliances
    Listed appliances equipped with draft hood
    Appliances listed for use with Type B gas vent    		 Single-wall metal pipe Section 802.7
    Listed Category I appliances
    Listed appliances equipped with draft hood
    Appliances listed for use with Type B gas vent    		 Listed chimney lining system for gas
    venting    		 Section 802.5.3
    Listed Category I appliances
    Listed appliances equipped with draft hood
    Appliances listed for use with Type B gas vent    		 Special gas vent listed for these
    appliances    		 Section 802.4.3
    Listed vented wall furnaces Type B-W gas vent Section 802.6, Section 907.0
    Category II, Category III, and
    Category IV appliances    		 As specified or furnished by
    manufacturers of listed appliances    		 Section 802.4.1, Section 802.4.
  • CRC § 0.52 High relevance — show source text

    R1004.5 Gasketed fireplace doors. A gasketed fireplace door shall not be installed on a factory-built fireplace except where the fireplace system has been specifically tested, listed and labeled for such use in accordance with UL 127.

    SECTION R1005—FACTORY-BUILT CHIMNEYS

    R1005.1 Listing. Factory-built chimneys shall be listed and labeled and shall be installed and terminated in accordance with the manufacturer’s installation instructions.

    R1005.2 Decorative shrouds. Decorative shrouds shall not be installed at the termination of factory-built chimneys except where the shrouds are listed and labeled for use with the specific factory-built chimney system and installed in accordance with the manufacturer’s installation instructions.

    R1005.3 Solid-fuel appliances. Factory-built chimneys installed in dwelling units with solid-fuel-burning appliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential Type and Building Heating Appliance Chimney.”

    Exception: Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 and shall be marked “Residential Type and Building Heating Appliance Chimney.”

    Chimneys for use with open combustion chamber appliances installed in buildings other than dwelling units shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” or “Residential Type and Building Heating Appliance Chimney.”

    R1005.4 Factory-built fireplaces. Chimneys for use with factory-built fireplaces shall comply with the requirements of UL 127.

    R1005.5 Support. Where factory-built chimneys are supported by structural members, such as joists and rafters, those members shall be designed to support the additional load.

    R1005.6 Medium-heat appliances. Factory-built chimneys for medium-heat appliances producing flue gases having a temperature above 1,000°F (538°C), measured at the entrance to the chimney, shall comply with UL 959.

    R1005.7 Factory-built chimney offsets. Where a factory-built chimney assembly incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical at any point in the assembly and the chimney assembly shall not include more than four elbows.

    R1005.8 Insulation shield. Where factory-built chimneys pass through insulated assemblies, an insulation shield constructed of steel having a thickness of not less than 0.0187 inch (0.4712 mm) (No. 26 gage) shall be installed to provide clearance between the chimney and the insulation material. The clearance shall be not less than the clearance to combustibles specified by the chimney manufacturer’s installation instructions. Where chimneys pass through attic space, the shield shall terminate not less than 2 inches (51 mm) above the insulation materials and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed chimney system shall be installed in accordance with the manufacturer’s installation instructions.

    R1005.9 Factory-built chimney offsets. Where a fireplace manufacturer’s instructions do not address factory-built chimney offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical at any point in the assembly and the chimney assembly shall not include more than four elbows.

    SECTION R1006—EXTERIOR AIR SUPPLY

  • CRC § 12.4.5.2 High relevance — show source text

    (2) The vent system shall be installed such that no fittings or joints between sections are installed in the above-ceiling space.

    (3) The venting system shall be installed in a conduit or enclosure with joints between the interior of the enclosure and the ceiling space sealed. [NFPA 54:12.4.5.2] 802.4 Type of Venting System to be Used. The type of venting system to be used shall be in accordance with Table 802.4. [NFPA 54:12.5.1]

    802.4.1 Plastic Piping. Where plastic piping is used to vent an appliance, the appliance shall be listed for use with such venting materials and the appliance manufacturer’s installation instructions shall identify the specific plastic piping material. The plastic pipe venting materials shall be labeled in accordance with the product standards specified by the appliance manufacturer or shall be listed and labeled in accordance with UL 1738. [NFPA 54:12.5.2]

    802.4.2 Plastic Vent Joints. Plastic pipe and fittings used to vent appliances shall be installed in accordance with the appliance manufacturer’s installation instructions. Plastic pipe venting materials listed and labeled in accordance with UL 1738 shall be installed in accordance

    with the vent manufacturer’s installation instructions. Where primer is required, it shall be of a contrasting color.

    [NFPA 54:12.5.3]

    802.4.3 Special Gas Vents. Special gas vents shall be listed and labeled in accordance with UL 1738 and installed in accordance with the special gas vent manufacturer’s installation instructions. [NFPA 54:12.5.4]

    802.5 Masonry, Metal, and Factory-Built Chimneys. Chimneys shall be installed in accordance with Section 802.5.1 through Section 802.5.3.

    802.5.1 Factory-Built Chimneys. Factory-built chimneys shall be listed in accordance with UL 103, UL 959, or UL 2561. Factory-built chimneys used to vent appliances that operate at positive vent pressure shall be listed for such application. [NFPA 54:12.6.1.1]

    802.5.1.1 Decorative Shrouds. Decorative shrouds addressed in Section 802.5.4.3 shall comply with UL 103 for factory-built residential chimneys, UL 127 for factory-built fireplaces, or UL 1482 for solid-fuel room heaters.

    802.5.2 Metal Chimneys. Metal chimneys shall be built and installed in accordance with NFPA 211. [NFPA 54:12.6.1.2]

    802.5.3 Masonry Chimneys. Masonry chimneys shall be built and installed in accordance with NFPA 211 and lined with one of the following:

    (1) Approved clay flue lining.

    (2) A chimney lining system listed and labeled in accordance with UL 1777.

    (3) Other approved material that resists corrosion, erosion, softening, or cracking from vent gases at temperatures up to 1800°F (982°C).

    Exception: Masonry chimney flues lined with a chimney lining system specifically listed for use with listed appliances with draft hoods, Category I appliances, and

    154 2025 CALIFORNIA MECHANICAL CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    CHIMNEYS AND VENTS

  • CRC § 25.4 High relevance — show source text

    br>G||||||||||||||| |FLUE
    LINING
    FLUE
    LINING

    G|||||||||||||||

    R1003.19 Chimney fireblocking. Spaces between chimneys and floors and ceilings through which chimneys pass shall be fireblocked with noncombustible material securely fastened in place. The fireblocking of spaces between chimneys and wood joists, beams or headers shall be self-supporting or be placed on strips of metal or metal lath laid across the spaces between combustible

    material and the chimney.
    R1003.20 Chimney crickets. Chimneys shall be provided with crickets where the dimension parallel to the ridgeline is greater than
    30 inches (762 mm) and does not intersect the ridgeline. The intersection of the cricket and the chimney shall be flashed and counter-
    flashed in the same manner as normal roof-chimney intersections. Crickets shall be constructed in compliance with Figure R1003.20
    and Table R1003.20.    		 Col2
    TABLE R1003.20—CRICKET DIMENSIONS TABLE R1003.20—CRICKET DIMENSIONS
    ** ROOF SLOPE** ** H**
    12:12 1/2 of W
    8:12 1/3 of W
    6:12 1/4 of W
    4:12 1/6 of W
    3:12 1/8 of W

    FIGURE R1003.20—CHIMNEY CRICKET

    AIRSPACE

    ROOF LINE

    For SI: 1 inch = 25.4 mm.

    FLUE LINER Col2 Col3 Col4 Col5
    1 IN.
    AIRS    		 1 IN.
    AIRS    		 1 IN.
    AIRS    		 1 IN.
    AIRS    		 1 IN.
    AIRS
    W W W W W

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    CHIMNEYS AND FIREPLACES

    SECTION R1004—FACTORY-BUILT FIREPLACES

    R1004.1 General. Factory-built fireplaces shall be listed and labeled and shall be installed in accordance with the conditions of the listing. Factory-built fireplaces shall be tested in accordance with UL 127.

    R1004.1.1 Factory-built wood burning fireplaces. Factory-built wood burning fireplaces shall be qualified at the U.S. EPA’s Volun- tary Fireplace Program Phase 2 emissions level and be in accordance with the California Green Building Standards Code, Chapter 4, Division 4.5.

    R1004.2 Hearth extensions. Hearth extensions of approved factory-built fireplaces shall be installed in accordance with the listing of the fireplace. The hearth extension shall be readily distinguishable from the surrounding floor area. Listed and labeled hearth extensions shall comply with UL 1618.

  • CRC § 0.52 High relevance — show source text

    R1005.6 Medium-heat appliances. Factory-built chimneys for medium-heat appliances producing flue gases having a temperature above 1,000°F (538°C), measured at the entrance to the chimney, shall comply with UL 959.

    R1005.7 Factory-built chimney offsets. Where a factory-built chimney assembly incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical at any point in the assembly and the chimney assembly shall not include more than four elbows.

    R1005.8 Insulation shield. Where factory-built chimneys pass through insulated assemblies, an insulation shield constructed of steel having a thickness of not less than 0.0187 inch (0.4712 mm) (No. 26 gage) shall be installed to provide clearance between the chimney and the insulation material. The clearance shall be not less than the clearance to combustibles specified by the chimney manufacturer’s installation instructions. Where chimneys pass through attic space, the shield shall terminate not less than 2 inches (51 mm) above the insulation materials and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed chimney system shall be installed in accordance with the manufacturer’s installation instructions.

    R1005.9 Factory-built chimney offsets. Where a fireplace manufacturer’s instructions do not address factory-built chimney offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical at any point in the assembly and the chimney assembly shall not include more than four elbows.

    SECTION R1006—EXTERIOR AIR SUPPLY

    R1006.1 Exterior air. Factory-built or masonry fireplaces covered in this chapter shall be equipped with an exterior air supply to ensure proper fuel combustion unless the room is mechanically ventilated and controlled so that the indoor pressure is neutral or positive.

    R1006.1.1 Factory-built fireplaces. Exterior combustion air ducts for factory-built fireplaces shall be a listed component of the fireplace and shall be installed in accordance with the fireplace manufacturer’s instructions.

    R1006.1.2 Masonry fireplaces. Listed combustion air ducts for masonry fireplaces shall be installed in accordance with the terms of their listing and the manufacturer’s instructions.

    R1006.2 Exterior air intake. The exterior air intake shall be capable of supplying all combustion air from the exterior of the dwelling unit or from spaces within the dwelling unit ventilated with outdoor air such as nonmechanically ventilated crawl or attic spaces. The

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    exterior air intake shall not be located within the garage or basement of the dwelling unit. The exterior air intake, for other than listed factory-built fireplaces, shall not be located at an elevation higher than the firebox. The exterior air intake shall be covered with a corrosion-resistant screen of [1] / 4 -inch (6.4 mm) mesh.

  • CRC § 10.7.3 High relevance — show source text

    (1) [HCD 1 & HCD 2] Any newly installed gas fireplace shall be a direct-vent sealed-combustion type.

    (2) Vented gas fireplaces shall be installed in accordance with their listing and the manufacturer’s installation instructions and where installed in or attached to com bustible material shall be specifically listed for such installation.

    (3) Panels, grilles, and access doors that are required to be removed for normal servicing operations shall not be attached to the building.

    (4) Direct vent gas fireplaces shall be installed with the vent air intake terminal in the outdoors and in accor dance with the manufacturer’s installation instructions.

    [NFPA 54:10.7.3] 912.4 Combustion and Circulating Air. Combustion and circulating air shall be provided in accordance with Section 701.0. [NFPA 54:10.7.4]

    913.0 Factory-Built Fireplaces and Fireplace Stoves. 913.1 Factory-Built Fireplaces. Factory-built fireplaces shall comply with UL 127 and installed in accordance with the manufacturer’s installation instructions. {NFPA 211:11.1.1} 913.1.1 Gasketed Fireplace Doors. A gasketed fireplace door shall not be installed on a factory-built fireplace, except where the fireplace system has been tested in accordance with UL 127.

    913.2 Fireplace Stoves. Fireplace stoves shall comply with UL 737 and installed in accordance with the manufac turer’s installation instructions.

    913.3 Fireplace Accessories. Heat exchangers, glass doors assemblies, combustion air vents, and termination caps shall comply with UL 907 and installed in accordance with the manufacturer’s installation instructions.

    914.0 Non-Recirculating Direct Gas-Fired Industrial Air Heaters.

    914.1 Application. Direct gas-fired heating and forced ventilation appliances for commercial and industrial applications shall be listed in accordance with the following standards as applicable:

    (1) ANSI Z83.4/CSA 3.7.

    (2) ANSI Z83.18. [NFPA 54:10.8.1] 914.2 Prohibited Installations. Direct gas-fired heating and forced ventilation appliances shall not serve any area containing sleeping quarters. Non-recirculating direct gas-fired heating and forced ventilation appliances shall not recirculate room air.

    Recirculating direct gas-fired industrial air heaters shall not recirculate room air in buildings that contain flammable solids, liquids, or gases; explosive materials; or substances that can become toxic when exposed to flame or heat. [NFPA 54:10.8.2.1 – 10.8.2.3]

    914.3 Installation. Direct gas-fired heating and forced ventilation appliances shall be installed in accordance with the manufacturer’s instructions. [NFPA 54:10.8.3.1]

    914.3.1 Fresh Air Ventilation. Direct gas-fired heating and forced ventilation appliances shall be permitted to provide fresh air ventilation. [NFPA 54:10.8.3.2]

    914.3.2 Access Required. Direct gas-fired heating and forced ventilation appliances shall be provided with access for removal of burners; for replacement of motors, controls, filters, and other working parts; and for adjustment and lubrication of parts requiring maintenance.

    [NFPA 54:10.8.3.3]

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  • CRC § 0.26 High relevance — show source text

    EXTERIOR WALL ASSEMBLY. A system or assembly of exterior wall components, including exterior wall covering materials, that provides protection of the building structural members, including framing and sheathing materials, and conditioned interior space, from the detri- mental effects of the exterior environment.

    EXTERIOR WALL COVERING. A material or assembly of materials applied on the exterior side of exterior walls for the purpose of providing a weather-resisting barrier, insulation or for aesthetics, including but not limited to, veneers, siding, exterior insulation and finish systems, architectural trim and embellishments such as cornices, soffits, facias, gutters and leaders.

    [RB] FACING. The wood structural panel facings that form the two outmost rigid layers of the structural insulated panel.

    [MP] FACTORY-BUILT CHIMNEY. A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer’s instructions and the conditions of the listing.

    [MP] FACTORY-MADE AIR DUCT. A listed and labeled duct manufactured in a factory and assembled in the field in accordance with the manufacturer’s instructions and conditions of the listing.

    FAMILY. (HCD 1) An individual or two or more persons who are related by blood or marriage; or otherwise live together in a dwelling unit.

    FENESTRATION. Products classified as either vertical fenestration or skylights and sloped glazing, installed in such a manner as to preserve the weather-resistant barrier of the wall or roof in which they are installed. Fenestration includes products with glass or other transparent or translucent materials.

    [RE] FENESTRATION, VERTICAL. Windows that are fixed or movable, opaque doors, glazed doors, glazed block and combination opaque and glazed doors installed in a wall at less than 15 degrees (0.26 rad) from vertical.

    [RB] FIBER-CEMENT (BACKERBOARD, SIDING, SOFFIT, TRIM AND UNDERLAYMENT) PRODUCTS. Manufactured thin section composites of hydraulic cementitious matrices and discrete nonasbestos fibers.

    [RB] FIRE SEPARATION DISTANCE. The distance measured from the building face to one of the following:

    1. To the closest interior lot line.

    2. To the centerline of a street, an alley or public way.

    3. To an imaginary line between two buildings or townhouse units on the lot.

    The distance shall be measured at a right angle from the face of the wall.

    [RB] FIREBLOCKING. Building materials or materials approved for use as fireblocking, installed to resist the free passage of flame to other areas of the building through concealed spaces.

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    DEFINITIONS

    [RB] FIREPLACE. An assembly consisting of a hearth and fire chamber of noncombustible material and provided with a chimney, for use with solid fuels.

    Factory-built fireplace. A listed and labeled fireplace and chimney system composed of factory-made components, and assembled in the field in accordance with manufacturer’s instructions and the conditions of the listing.

    Masonry fireplace. A field-constructed fireplace composed of solid masonry units, bricks, stones or concrete.

  • CRC § 2025 High relevance — show source text

    Chapter 9 Roof Assemblies.

    Chapter 9 regulates the design and construction of roof assemblies. A roof assembly includes the roof deck, vapor retarder, substrate or thermal barrier, insulation, vapor retarder and roof covering. This chapter provides the requirement for wind resistance of roof coverings.

    The types of roof covering materials and installation regulated by Chapter 9 are: asphalt shingles, clay and concrete tile, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shakes and shingles, built-up roofs, metal roof panels, modified bitumen roofing, thermoset and thermoplastic single-ply roofing, sprayed polyurethane foam roofing, liquid applied coatings and photovoltaic shingles. Chapter 9 also provides requirements for roof drainage, flashing, above deck thermal insulation, rooftop-mounted photovoltaic systems and recovering or replacing an existing roof covering.

    Chapter 10 Chimneys and Fireplaces.

    Chapter 10 contains requirements for the safe construction of masonry chimneys and fireplaces and establishes the standards for the use and installation of factory-built chimneys, fireplaces and masonry heaters. Chimneys and fireplaces constructed of masonry rely on prescriptive requirements for the details of their construction; the factory-built type relies on the listing and labeling method of approval. Chapter 10 provides the requirements for seismic reinforcing and anchorage of masonry fireplaces and chimneys.

    Chapter 11 [RE] Energy Efficiency.

    Chapter 11 is not adopted in California. See California Energy Code, Title 24, Part 6.

    Chapter 12 Mechanical Administration.

    Chapter 12 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 13 General Mechanical System Requirements.

    Chapter 13 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 14 Heating and Cooling Equipment and Appliances.

    Chapter 14 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 15 Exhaust Systems.

    Chapter 15 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 16 Duct Systems.

    Chapter 16 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 17 Combustion Air.

    Chapter 17 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 18 Chimneys and Vents.

    Chapter 18 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 19 Special Appliances, Equipment and Systems.

    Chapter 19 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 20 Boilers and Water Heaters.

    Chapter 20 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

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    Chapter 21 Hydronic Piping.

    Chapter 21 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 22 Special Piping and Storage Systems.

    Chapter 22 is not adopted in California. See California Mechanical Code, Title 24, Part 4.

    Chapter 23 Solar Thermal Energy Systems.

  • CRC § 2025 High relevance — show source text

    Chapter 6 also regulates exterior windows and doors installed in walls. This chapter contains criteria for the performance of exterior windows and doors and includes provisions for testing and labeling, garage doors, windborne debris protection and anchorage details.

    Chapter 7 Wall Covering.

    Chapter 7 contains provisions for the design and construction of interior and exterior wall coverings. This chapter establishes the various types of materials, materials standards and methods of application permitted for use as interior coverings, including interior plaster, gypsum board, ceramic tile, wood veneer paneling, hardboard paneling, wood shakes and wood shingles. Chapter 7 also contains requirements for the use of vapor retarders for moisture control in walls.

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    Exterior wall coverings provide the weather-resistant exterior envelope that protects the building’s interior from the elements. Chapter 7 provides the requirements for wind resistance and water-resistive barrier for exterior wall coverings. This chapter prescribes the exterior wall coverings as well as the water-resistive barrier required beneath the exterior materials. Exterior wall coverings regulated by this section include aluminum, stone and masonry veneer, wood, hardboard, particleboard, wood structural panel siding, wood shakes and shingles, exterior plaster, steel, vinyl, fiber cement and exterior insulation finish systems.

    Chapter 8 Roof-Ceiling Construction.

    Chapter 8 regulates the design and construction of roof-ceiling systems. This chapter contains two roof-ceiling framing systems: wood framing and cold-formed steel framing. Allowable span tables are provided to simplify the selection of rafter and ceiling joist size for wood roof framing and cold-formed steel framing. Chapter 8 also provides requirements for the application of ceiling finishes, the proper ventilation of concealed spaces in roofs (e.g., enclosed attics and rafter spaces), unvented attic assemblies and attic access.

    Chapter 9 Roof Assemblies.

    Chapter 9 regulates the design and construction of roof assemblies. A roof assembly includes the roof deck, vapor retarder, substrate or thermal barrier, insulation, vapor retarder and roof covering. This chapter provides the requirement for wind resistance of roof coverings.

    The types of roof covering materials and installation regulated by Chapter 9 are: asphalt shingles, clay and concrete tile, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shakes and shingles, built-up roofs, metal roof panels, modified bitumen roofing, thermoset and thermoplastic single-ply roofing, sprayed polyurethane foam roofing, liquid applied coatings and photovoltaic shingles. Chapter 9 also provides requirements for roof drainage, flashing, above deck thermal insulation, rooftop-mounted photovoltaic systems and recovering or replacing an existing roof covering.

    Chapter 10 Chimneys and Fireplaces.

    Chapter 10 contains requirements for the safe construction of masonry chimneys and fireplaces and establishes the standards for the use and installation of factory-built chimneys, fireplaces and masonry heaters. Chimneys and fireplaces constructed of masonry rely on prescriptive requirements for the details of their construction; the factory-built type relies on the listing and labeling method of approval. Chapter 10 provides the requirements for seismic reinforcing and anchorage of masonry fireplaces and chimneys.

    Chapter 11 [RE] Energy Efficiency.

    Chapter 11 is not adopted in California. See California Energy Code, Title 24, Part 6.

    Chapter 12 Mechanical Administration.

  • CRC § 1.1 High relevance — show source text

    SECTION R1006—EXTERIOR AIR SUPPLY

    R1006.1 Exterior air. Factory-built or masonry fireplaces covered in this chapter shall be equipped with an exterior air supply to ensure proper fuel combustion unless the room is mechanically ventilated and controlled so that the indoor pressure is neutral or positive.

    R1006.1.1 Factory-built fireplaces. Exterior combustion air ducts for factory-built fireplaces shall be a listed component of the fireplace and shall be installed in accordance with the fireplace manufacturer’s instructions.

    R1006.1.2 Masonry fireplaces. Listed combustion air ducts for masonry fireplaces shall be installed in accordance with the terms of their listing and the manufacturer’s instructions.

    R1006.2 Exterior air intake. The exterior air intake shall be capable of supplying all combustion air from the exterior of the dwelling unit or from spaces within the dwelling unit ventilated with outdoor air such as nonmechanically ventilated crawl or attic spaces. The

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    CHIMNEYS AND FIREPLACES

    exterior air intake shall not be located within the garage or basement of the dwelling unit. The exterior air intake, for other than listed factory-built fireplaces, shall not be located at an elevation higher than the firebox. The exterior air intake shall be covered with a corrosion-resistant screen of [1] / 4 -inch (6.4 mm) mesh.

    R1006.3 Clearance. Unlisted c ombustion air ducts shall be installed with a minimum 1-inch (25 mm) clearance to combustibles for all parts of the duct within 5 feet (1524 mm) of the duct outlet. R1006.4 Passageway. The combustion air passageway shall be not less than 6 square inches (3870 mm [2] ) and not more than 55 square inches (0.035 m [2] ), except that combustion air systems for listed fireplaces shall be constructed in accordance with the fireplace manufacturer’s instructions.

    R1006.5 Outlet. The exterior air outlet shall be located in the back or side of the firebox chamber or shall be located outside of the firebox, at the level of the hearth and not greater than 24 inches (610 mm) from the firebox opening. The outlet shall be closable and designed to prevent burning material from dropping into concealed combustible spaces.

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    Part IV—Energy Conservation

    (Note: Part IV is not adopted. See California Energy Code, Title 24, Part 6.)

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    Part V—Mechanical

    (Note: Part V is not adopted. See California Mechanical Code, Title 24, Part 4.)

  • CRC § 10-12 High relevance — show source text

    R1004 Factory-Built Fireplaces. . . . . . . . . . . . . . . . . . . . . . . . 10-12

    R1005 Factory-Built Chimneys . . . . . . . . . . . . . . . . . . . . . . . . 10-12

    R1006 Exterior Air Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12

    Part IV—Energy Conservation. . . . . . . . . . . . . . . . . . . . . . . .11-1

    Part V—Mechanical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-1

    Part VI—Fuel Gas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24-1

    Part VII—Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25-1

    Part VIII—Electrical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34-1

    Part IX— Referenced Standards . . . . . . . . . . . . . . . . . . . . . .44-3

    CHAPTER 44 REFERENCED STANDARDS . . . . . . . . . . . . . .44-3

    APPENDIX AA BOARD OF APPEALS. . . . . . . . . . APPENDIX AA-3

    AA101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX AA-3

    APPENDIX AB PERMIT FEES. . . . . . . . . . . . . . . . APPENDIX AB-3

    AB101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX AB-3

    APPENDIX AC RESERVED . . . . . . . . . . . . . . . . . . APPENDIX AC-1

    APPENDIX BA RESERVED . . . . . . . . . . . . . . . . . . APPENDIX BA-1

    APPENDIX BB TINY HOUSES . . . . . . . . . . . . . . . APPENDIX BB-3

    BB101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX BB-3

    BB102 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX BB-3

    BB103 Ceiling Height . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX BB-3

    BB104 Lofts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX BB-3

Frequently asked questions

Can I install any aftermarket decorative cap or shroud on a listed factory-built chimney?

No — decorative shrouds at the termination are prohibited unless the shroud is listed and labeled for use with that specific factory-built chimney system and installed per the manufacturer’s instructions. § R1005.2

Is a gasketed (sealed) door allowed on a factory-built fireplace?

Not unless the entire fireplace system (including the door configuration) has been specifically tested, listed and labeled for gasketed doors in accordance with UL 127. § R1004.5

What if my chimney needs multiple offsets to avoid structure conflicts?

Each part of the chimney must stay within 30° of vertical, and the assembly may include no more than four elbows; if manufacturer instructions address offsets, follow them; if not, these limits apply. § R1005.7; § R1005.9

Are factory-built chimneys for wood stoves different than for factory-built fireplaces?

Yes — chimneys for certain appliances (solid-fuel, medium-heat) have different UL requirements (e.g., Type HT / UL 103 for solid fuel; UL 959 for medium-heat >1,000°F). Confirm the chimney is listed for the specific appliance and marked as required. § R1005.3; § R1005.6

Who controls clearance requirements — the code or the manufacturer?

The code requires that factory-built systems be installed in accordance with the conditions of the listing; the manufacturer's listing/installation instructions (the listing) control the exact clearance and related installation details for that product. § R1004.1; § R1005.1

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What marking and UL requirements apply for factory-built chimneys serving solid-fuel or medium-heat appliances?

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What limits apply to chimney offsets, insulation shields and elbow counts for factory-built chimneys?

Factory-built Fireplaces & Chimneys

California Residential Code