CRSC · California Referenced Standards Code
What key terms and definitions (e.g., 'installed design density', 'exposed application') apply to this chapter?
This article explains the key definitions in the California Referenced Standards Code for insulation — most importantly that **installed design density** is the manufacturer‑proven loose‑fill density limiting settlement to 2% in 3 years (4% in 15), and **exposed application** is an interior use without Chapter‑8 CBC material in substantial contact with the facing; these definitions determine how insulation is tested, labeled and installed under the CRSC (§ 12-13-1552) .
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
This article establishes the specific definitions used for the insulating-material standards in Article 3; those definitions control how the tests, labeling and performance requirements are applied throughout the Article. The controlling definitions are contained in § 12-13-1552 and must be used when interpreting the rest of the insulating-material provisions (for example: testing, labeling, density, and what counts as an exposed application) .
The single most important definitional rule: “Installed design density” is the manufacturer‑determined density for loose-fill (non-cellulose) insulation that limits settlement to no more than 2% over the first 3 years or no more than 4% over the first 15 years of installation — this is the density manufacturers must use for testing, labeling and installer guidance (see § 12-13-1552(f)) .
Requirements in detail
Below are the key defined terms from § 12-13-1552 with a plain-English restatement and how each term is used in the Article (citations show where the definition appears).
§ 12-13-1552 — Definitions (controlling section). All terms below are defined in this section and are used throughout the Article 3 insulating‑material standards .
“Approved laboratory” — a testing facility (including manufacturer labs) that has been approved under Section 1554 (used when tests must be performed by an approved lab) .
“ANSI” and “ASTM” — shorthand references to the named standards bodies used throughout the Article; use the standards listed by those acronyms as referenced in test and performance requirements .
“Building materials” — materials used in walls, ceilings, roofs and floors; this anchors what the Article means by materials covered by the standards .
“Exposed application” — any interior use of an insulation product in which the product is not installed as part of a construction assembly that places a Chapter‑8 CBC material in substantial contact with the facing or membrane surface. In short: interior uses without a Chapter‑8 contact material are “exposed” (this affects flammability labeling and permitted uses) § 12-13-1552(e) .
“Installed design density” — the manufacturer‑proven density for loose‑fill insulation (other than cellulose) determined so settlement is ≤ 2% in 3 years or ≤ 4% in 15 years; manufacturers must use this density for thermal and many other tests and include it in labeling and installation guidance § 12-13-1552(f) . The Article also requires that manufacturers mark containers with the installed design density used to demonstrate thermal performance and to show recommended wall density where applicable .
“Insulating material” / “insulation” — any material listed in Section 1551(b) (the Article’s scope list) placed within or contiguous to walls, ceilings, roofs, floors or appliance surfaces to reduce heat transfer; this ties the definitions to the Article scope (see § 12-13-1552(g) and § 12-13-1551) .
“Manufacturer” — the party that produces the insulating material (or, for on‑site foams, the primary component producer); expressly excludes a contractor whose only activity is installing insulation § 12-13-1552(h) .
“Recommended wall density”, “Representative sample”, “Representative thickness”, “TAPPI” — additional definitions that appear in § 12-13-1552(j–m) and are used in testing, marking and reporting requirements (for example, representative thickness ties to how thermal tests must be run) .
Decision‑relevant values and where they matter (table)
| Term | Decision‑relevant value(s) | How it is used / affects decisions | Code reference |
|---|---|---|---|
| Installed design density | ≤ 2% settlement in first 3 years; ≤ 4% settlement in first 15 years | Manufacturer selects IDD; tests for thermal performance and many tests are conducted at that density; labels must show IDD used for R‑value testing | § 12-13-1552(f) |
| Exposed application | Interior application without a Chapter‑8 CBC material in substantial contact with facing/membrane | Determines whether a product is considered "exposed" for flammability labeling and permitted use; high flame‑spread facings require special labeling when used exposed | § 12-13-1552(e) |
| Representative thickness | ±2% change per inch (performance variance threshold) | Tests for thermal performance must be conducted at representative thickness; affects recertification/testing schedule | § 12-13-1552(l); testing rules elsewhere |
| Manufacturer (exclusion) | Contractor who only installs is NOT a manufacturer | Impacts who is responsible for labeling, testing and providing IDD data | § 12-13-1552(h) |
Exceptions & special cases
The definition of “exposed application” explicitly looks to whether a construction assembly imposes a Chapter‑8 CBC material in substantial contact with the facing or membrane surface; if such a contact exists, the application is not “exposed” under § 12-13-1552(e). That distinction matters for labeling and combustibility statements (see labeling rules elsewhere in the Article) .
The manufacturer definition excludes installers/contractors; therefore responsibility for test data, IDD determination and labeling falls on the manufacturer, not a mere installer, per § 12-13-1552(h) .
Where a loose‑fill product is used for pressure‑fill retrofit wall applications, the product must be separately tested and marked with the recommended wall density to prevent settling and with the tested thermal performance for that application (marking requirement referenced in other Article sections) .
If a product’s facing/membrane produces a flame‑spread value over 25 on the ANSI/ASTM E84 test when facings are exposed, the product must be clearly labeled that it “may be highly combustible if used in an exposed application” (see the Article’s labeling provisions that rely on the exposed application definition) .
Common mistakes
Treating an installer as the “manufacturer” — only the party that produces the material (or primary components for site‑formed foams) is the manufacturer per § 12-13-1552(h); this affects who must provide test data and IDD documentation .
Using the wrong density when testing or labeling — tests for loose‑fill products (non‑cellulose) must be conducted at the installed design density the manufacturer claims; that IDD must be documented and included in identifying information and container markings .
Misinterpreting “exposed application” as exterior exposure — the definition in § 12-13-1552(e) specifically defines an interior situation where the facing/membrane is not in substantial contact with a Chapter‑8 CBC material; don’t confuse interior/exterior terms or substitute other building‑code chapters without checking the exact wording .
Forgetting settlement thresholds — installed design density is defined by settlement limits (2% / 4%); using a lower density without evidence will not meet the definition or the testing/labelling expectations in the Article .
Worked example — applying installed design density with numbers
Scenario (hypothetical numbers used only for illustration): a manufacturer certifies a loose‑fill mineral‑fiber insulation with an installed design density (IDD) of 2.0 lb/ft3 and lists an installed thickness of 10 inches (0.833 ft) to achieve the labeled R‑value.
Compute installed weight per square foot for the labeled application:
- Weight/ft2 = IDD × thickness (ft) = 2.0 lb/ft3 × 0.833 ft = 1.67 lb/ft2.
- That installed weight per ft2 is the value a contractor would use to achieve the manufacturer’s labeled R‑value at the IDD (the Article ties installed weight per ft2 to the manufacturer’s IDD and labeled R‑value) .
Settlement limits per the definition:
- Over the first 3 years, settlement must be ≤ 2%. For this installation that means an allowable loss of installed weight ≤ 0.033 lb/ft2 (2% of 1.67 lb/ft2).
- Over 15 years, settlement must be ≤ 4% (i.e., ≤ 0.067 lb/ft2 in this example) — the manufacturer’s IDD is the density demonstrated to meet those limits § 12-13-1552(f) .
Practical impacts:
- The manufacturer must document that 2.0 lb/ft3 produces the settlement performance claimed and must include the IDD and installation guidance on the product marking and literature; testing for thermal performance is conducted at that IDD per the Article’s test rules .
Related provisions
- § 12-13-1551 — Application and scope of the Article (which insulating materials are covered) .
- § 12-13-1554 — Approval of testing laboratories (defines approved lab process referenced by “approved laboratory”) .
- § 12-13-1555 — Certification/testing requirements (tests and certification referenced by the Article) .
- § 12-13-1557 — Labeling / identifying information requirements (manufacturer must include IDD and installation recommendations on containers) .
- § 12-13-1558 — Inspections (Commission access for compliance checks and sample collection) .
- § 12-13-1559 — Independent performance tests the Commission may conduct .
- § 12-13-1564 — Requirements for insulating existing buildings; references installed weight per square foot and conformity to manufacturer’s IDD and labeled R‑value .
Code references
Grounded in the retrieved California Referenced Standards Code — click a citation to read the verbatim passage:
CRSC § 1551-1561 High relevance — show source text
HISTORY:
- Repealer of Article 3 (Sections 1551-1561) filed 8-11-78; effective thirtieth day thereafter (Register 78, No. 32). For prior history, see Registers 76, No. 16; 78, Nos. 2 and 26.
- New Article 3 (Sections 1551-1565) filed 1-16-79; effective thirtieth day thereafter (Register 79, No. 3).
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
DEFINITIONS
Sec. 12-13-1552. For purposes of this article, the following definitions shall apply:
(a) “Approved laboratory” means any testing facility including a facility owned or operated by a manufacturer which has been approved pursuant to Section 1554 of this article.
(b) “ANSI” means the American National Standards Institute.
(c) “ASTM” means ASTM International.
(d) “Building materials” means materials used in walls, ceilings, roofs and floors of buildings.
(e) “Exposed application” means any interior application of the product in which it is not used in a construction assembly imposing a material which meets the requirements of Chapter 8 of the California Building Code in substantial contact with the facing or membrane surface.
(f) “Installed design density” means the proven density for loose fill insulation other than cellulose which has been determined by the manufacturer to constitute the density whereby settlement of no more than 2 percent shall occur over the first three years, or no more than 4 percent over the first 15 years of installation.
(g) “Insulating material” or “insulation” means any material listed in Section 1551 (b) of this article and placed within or contiguous to a wall, ceiling, roof or floor of a room or building, or contiguous to the surface of any appliance or its intake or outtake mechanism, for the purpose of reducing heat transfer or reducing adverse temperature fluctuations of the building room or appliance.
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(h) “Manufacturer” means any person who either:
- Produces insulating material in the final composition either for use in the form sold or to be further dimensionally modified; or
- In the case of polyurethane, polyisocyanurate and urea formaldehyde foam formed at the installation site, produces the primary components of the material.
“Manufacturer” shall not include any building contractor or any other person whose sole activity is to install insulation at the installation site.
(i) “Quality assurance program.” (Reserved)
(j) “Recommended wall density” means the density used for pressure fill retrofit wall applications to prevent settling.
(k) “Representative sample” means a sample of insulating material with the same characteristics (other than thickness) and using the same facing imposed on the insulating material manufactured for final use.
(l) “Representative thickness” means a thickness of insulating material at which the change in thermal performance per inch will vary no more than plus or minus 2 percent with increases in thickness.
(m) “TAPPI” means Technical Association of Pulp and Paper Industry.
CRSC § 410-66. High relevance — show source text
Insulation boards exclusive of facings and membranes shall not exceed the following values:
Flame spread. . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Smoke developed. . . . . . . . . . . . . . . . . . . . . . . 50 (i) Mineral fiber in loose fill form.
- Composition. Mineral fiber insulation shall be made from mineral substances such as rock, slag or glass processed from a molten state into fibrous form. The insulation shall be mechanically processed to produce a mineral fiber suitable for pneumatic or poured application.
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- Thermal performance. Determination of the thermal performance shall be in accordance with ANSI/ASTM C177-76, ANSI/ASTM C236-66 or ANSI/ASTM C518-76 at the manufacturer’s option.
- Density. The density shall be determined according to installed design density. All tests shall be conducted at the installed design density.
- Resistance to combustion. Loose fill insulation shall comply with the United States General Services Administration insulation standard HH-I-1030B dated August 12, 1980, for flammability and smoldering combustion testing.
- Corrosiveness. Corrosiveness shall be determined according to Test Description Number 2. The steel plate in contact with the insulation shall show no greater corrosion than a steel plate in contact with sterile cotton.
- Resistance to fungi. Resistance to fungi shall be determined according to Method 508 of the March 10, 1975, edition of the Military Standard for Environmental Test Methods known as MIL-STD-810C, except the spore suspensions shall be prepared using distilled water. The core of gypsum wall board shall be used as the control. After the test exposure, the test samples shall show no more fungal growth than the control material when examined at 40 times magnification.
- Odor emission. Odor emission shall be determined according to Test Description Number 1. A detectable odor of objectionable nature observed by two or more of the panel members shall be cause for rejection.
- Identification. Each insulation container shall be marked with the type (pouring or pneumatic), the net weight and the manufacturer’s recommendations for installation including minimum thickness, maximum coverage and installed design density to provide the levels of thermal performance shown. Manufacturer’s installation recommendations shall include precautions according to the California Electrical Code Section 410-66. Products which may be used for pressure fill retrofit wall application shall be marked with the recommended wall density to prevent settling and separately marked with the tested thermal performance for such applications.
(j) Perlite in loose fill form.
- Composition. Expanded perlite loose fill insulation shall be produced by the expanding of natural perlite or by heating.
- Thermal performance. Determination of the thermal performance shall be in accordance with ANSI/ASTM C177-76, ANSI/ASTM C236-66 or ANSI/ASTM C518-76 at the manufacturer’s option.
- Density. Density shall be determined according to installed design density. All tests except the ANSI/ASTM E84-79 test shall be conducted at the installed design density.
- **Resistance to combustion.
CRSC § 12-13 High relevance — show source text
ARTICLE 3. STANDARDS FOR INSULATING MATERIAL
APPLICATION AND SCOPE
Sec. 12-13-1551.
(a) This article establishes standards governing the quality of insulation sold within the state after September 22, 1981, including those properties which affect the safety and thermal performance of insulation during application and in the use intended.
(b) The provisions of this article shall apply only to the following types of insulating material:
Aluminum foil (reflective foil);
Cellular glass (board form);
Cellulose fiber (loose fill and spray applied);
Mineral aggregate (board form);
Mineral fiber (blankets, board form, loose fill);
Perlite (loose fill);
Polystyrene (board form, molded and extruded);
Polyurethane (board form and field applied);
Polyisocyanurate (board form and field applied);
Urea formaldehyde foam (field applied);
Vermiculite (loose fill).
(c) The provisions of this article shall apply to the sale of insulating material within the state. The provisions of this article shall not apply to insulating material manufactured in California, but sold outside the state, nor to insulating material manufactured outside California and sold wholesale in California for final retail sale outside the state. For the purpose of this article, the sale of a building or an appliance which contains installed insulating material is not considered the sale of the insulating material.
(d) Any type of insulating material not listed in subsection (b) may be sold within California notwithstanding any other provision of this article.
Authority: Sections 25920 and 25922, Public Resources Code.
Reference: Sections 25910, 25920, 25921 and 25922, Public Resources Code.
HISTORY:
- Repealer of Article 3 (Sections 1551-1561) filed 8-11-78; effective thirtieth day thereafter (Register 78, No. 32). For prior history, see Registers 76, No. 16; 78, Nos. 2 and 26.
- New Article 3 (Sections 1551-1565) filed 1-16-79; effective thirtieth day thereafter (Register 79, No. 3).
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
DEFINITIONS
Sec. 12-13-1552. For purposes of this article, the following definitions shall apply:
(a) “Approved laboratory” means any testing facility including a facility owned or operated by a manufacturer which has been approved pursuant to Section 1554 of this article.
(b) “ANSI” means the American National Standards Institute.
(c) “ASTM” means ASTM International.
(d) “Building materials” means materials used in walls, ceilings, roofs and floors of buildings.
(e) “Exposed application” means any interior application of the product in which it is not used in a construction assembly imposing a material which meets the requirements of Chapter 8 of the California Building Code in substantial contact with the facing or membrane surface.
(f) “Installed design density” means the proven density for loose fill insulation other than cellulose which has been determined by the manufacturer to constitute the density whereby settlement of no more than 2 percent shall occur over the first three years, or no more than 4 percent over the first 15 years of installation.
CRSC § 410-66. High relevance — show source text
**
- Composition. Vermiculite loose fill insulation shall be produced by the expanding or exfoliating of natural vermiculate or by grading and heating.
- Thermal performance. Determination of the thermal performance shall be in accordance with ANSI/ASTM C177-76, ANSI/ASTM C236-66 or ANSI/ASTM C615-76 at the manufacturer’s option.
- Density. Density shall be determined according to installed design density. All tests except the ANSI/ ASTM E84-79 test shall be conducted at the installed design density.
- Resistance to combustion. Resistance to combustion shall be determined by the use of the Attic Floor Radiant Panel Test, as described in the United States General Services Administration insulation standard HH-I-515D as amended October 11, 1979.
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- Identification. Containers of vermiculite shall be marked with the type (pouring or pneumatic), the net weight and the manufacturer’s recommendations for installation including minimum thickness, maximum coverage and installed design density to provide the levels of thermal performance shown. Manufacturer’s installation recommendations shall include precautions according to the California Electric Code Section 410-66.
Products which may be used for pressure fill retrofit wall application shall be marked with the recommended wall density to prevent settling and separately marked with the tested thermal performance for such applications.
Authority: Sections 25402(a) and 25920, Public Resources Code.
Reference: Sections 25920-25922, Public Resources Code.
HISTORY:
- Amendment of subsection (a) (9) filed 4-2-79; effective thirtieth day thereafter (Register 79, No. 14).
- Editorial correction of subsection designations with subsection (l) (4) (Register 79, No. 17).
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
- New subsection (m) (2) (J) filed 9-11-81; effective thirtieth day thereafter (Register 81, No. 37).
- Editorial correction of subsection (k) (3) (B) filed 1-13-82 (Register 82, No. 3).
- Amendment of subsections (a) (5) and (a) (8) filed 5-5-82; effective thirtieth day thereafter (Register 82, No. 19).
- Editorial correction of subsection (m) printing error (Register 82, No. 44).
APPROVAL OF TESTING LABORATORIES
Sec. 12-13-1554.
(a) Except as provided in subsection (b), laboratories shall be approved using the procedures described in the Criteria for the Approval of Testing Laboratories, dated October 27, 1978. The Executive Director shall approve any laboratory that meets the standards described in the Criteria for the Approval of Testing Laboratories, dated October 27, 1978. A testing laboratory shall have the right to appeal to the full Commission any denial of approval by the Executive Director.
CRSC § 64703-64705. Medium relevance — show source text
This installed weight per square foot shall conform with the manufacturer’s installed design density per square foot at the manufacturer’s labeled R -value.
(b) Water heater insulation kits. No water heater insulation kit shall be sold, on or after March 25, 1982, unless it has a thermal resistance of at least R-6 and is so identified.
Each water heater insulation kit sold shall include instructions which are equivalent to the Department of Energy standard practice for the installation of insulation on gas-fired, oil-fired and electric resistance water heaters, 44 Fed. Reg. pages 64703-64705.
Authority: Section 25922, Public Resources Code.
Reference: Section 25922, Public Resources Code.
HISTORY:
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
- Editorial correction of subsection (a) filed 1-13-82 (Register 82, No. 2).
INTERPRETATION
Sec. 12-13-1565.
The General Counsel of the Commission shall make a determination as to the application or interpretation of any provision of this article to any person requesting such a determination. Any such request shall be submitted in writing to the Commission. The Commission shall make written replies to such inquiries and shall widely publish interpretations that have broad application or interest.
Authority: Section 25218 (e), Public Resources Code.
Reference: Sections 25920 and 25922, Public Resources Code.
HISTORY:
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
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12-16-1 ENGINEERING REGULATIONS—QUALITY AND
DESIGN OF THE MATERIALS OF CONSTRUCTION
CALIFORNIA STANDARD FOR EARTHQUAKE-ACTUATED AUTOMATIC GAS SHUTOFF SYSTEMS (SEE CCR TITLE 24, PART 2, CHAPTERS 16 AND 16A, AND CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-1
DIVISION OF THE STATE ARCHITECT
Authority: Sections 19180–19183, Health and Safety Code. Reference: Section 19182, Health and Safety Code.
DIVISION 1—CONSTRUCTION
SCOPE
Sec. 12-16-101. The American Society of Civil Engineers (ASCE) requirements for “Earthquake-Actuated Automatic Gas Shutoff Devices,” ANSI/ASCE/SEI 25-16 (copyright 2016 by ASCE), shall be the applicable standard used by the Division of the State Architect for the certification of these devices.
Sec. 12-16-101.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).
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12-16-2 ENGINEERING REGULATIONS—QUALITY AND
CRSC § 25.4 Medium relevance — show source text
The interior and exterior cob faces shall be permitted to be unfinished or receive any plaster finish allowed by this appendix.
d.
Cob walls with more than one density shall be built with heavier densities below lighter densities.
e.
Minimum cob wall thickness shall be whichever is greater in Tables BK105.3, BK106.11(1) and BK108.1.
f.
Wall thicknesses less than 10 inches require an engineered design.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 0.45 kg, 1 pound per cubic foot = 16.02 kg/m3.
a.
Density is to be measured at equilibrium moisture content. Average wall density shall be within ±5 pcf of the tabulated value.
b.
Requires an approved engineered design per Section BK106.6.
c.
Cob thickness only. The interior and exterior cob faces shall be permitted to be unfinished or receive any plaster finish allowed by this appendix.
d.
Cob walls with more than one density shall be built with heavier densities below lighter densities.
e.
Minimum cob wall thickness shall be whichever is greater in Tables BK105.3, BK106.11(1) and BK108.1.
f.
Wall thicknesses less than 10 inches require an engineered design.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 0.45 kg, 1 pound per cubic foot = 16.02 kg/m3.
a.
Density is to be measured at equilibrium moisture content. Average wall density shall be within ±5 pcf of the tabulated value.
b.
Requires an approved engineered design per Section BK106.6.
c.
Cob thickness only. The interior and exterior cob faces shall be permitted to be unfinished or receive any plaster finish allowed by this appendix.
d.
Cob walls with more than one density shall be built with heavier densities below lighter densities.
e.
Minimum cob wall thickness shall be whichever is greater in Tables BK105.3, BK106.11(1) and BK108.1.
f.
Wall thicknesses less than 10 inches require an engineered design.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 0.45 kg, 1 pound per cubic foot = 16.02 kg/m3.
a.
Density is to be measured at equilibrium moisture content. Average wall density shall be within ±5 pcf of the tabulated value.
b.
Requires an approved engineered design per Section BK106.6.
c.
Cob thickness only. The interior and exterior cob faces shall be permitted to be unfinished or receive any plaster finish allowed by this appendix.
d.
Cob walls with more than one density shall be built with heavier densities below lighter densities.
e.
Minimum cob wall thickness shall be whichever is greater in Tables BK105.3, BK106.11(1) and BK108.1.
f.
Wall thicknesses less than 10 inches require an engineered design.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 0.45 kg, 1 pound per cubic foot = 16.02 kg/m3.
a.
Density is to be measured at equilibrium moisture content.CRSC § 0.75. Medium relevance — show source text
- Except as provided in Items 5 and 6, the thermal performance test results certified under Section 1555 of this article shall be the average of the values obtained from at least three tests.
- The average measured thermal performance of the tests required by Items 5, 6 and 7 shall not be more than 5 percent below the value specified on the product. In addition, all insulation material sold within the state after September 22, 1981, shall have a measured thermal performance not more than 10 percent below the value specified on the product.
- All numbered test descriptions shall be contained in the document “Test Descriptions for Insulating Material” dated February 27, 1981.
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STANDARDS FOR INSULATING MATERIAL
Facings on representative samples may be removed or modified by slitting for the ANSI/ASTM C177-76 and ANSI/ASTM C518-76 tests.
All thermal performance testing equipment used for testing insulating materials shall be calibrated with samples referenced to the United States National Bureau of Standards.
Manufacturers of loose fill insulations for which no settled density test is required by this section shall be required to include the installed design density in the identifying information described in Section 1557. The manufacturer shall provide sufficient documentation to establish a valid basis for the determination of installed design density. The Executive Director shall determine whether a valid basis exists for the installed design density claimed by the manufacturer. If it is determined that a valid basis does not exist, the director may assign an appropriate installed design density or may require an appropriate test to determine the installed design density. The manufacturer may appeal the Executive Director’s determination to the full Commission.
Within 180 days after the availability of appropriate representative thickness calibration samples from the National Bureau of Standards, all insulating materials thicker than 1 inch (25 mm), which have not previously been tested at the representative thickness of a representative sample, shall be tested at representative thickness and recertified. Test results and a revised certification statement will be submitted to the Executive Director. The Executive Director shall determine if and when an appropriate representative thickness calibration sample is available from the National Bureau of Standards and shall publish a list of available representative thickness calibration samples. The manufacturer may appeal the Executive Director’s determination to the full Commission.
All products which may be used for pressure fill retrofit wall application shall be separately tested for thermal performance using a sample prepared at the manufacturer’s recommended wall density for such applications.
All water heater insulation kits and nonpreformed pipe insulation shall be tested for thermal performance at the installed compressed thickness of a typical application. Installed compressed thickness shall be determined according to Test Description Number 6. All nonpreformed duct insulation shall be labeled, in accordance with Section 1557(c), with an installed R -value equal to the R -value of the uncompressed insulation times 0.75. (b) Aluminum foil.
Composition. The insulation shall have uniform flat surfaces and shall not be crumpled, torn or punctured. Aluminum foil shall contain not less than 99 percent aluminum. Kraft paper and flangeboard shall meet the requirements of ANSI/TAPPI T400 0S75. Flangeboard used for more than two insulation layers shall be of 28 point grade minimum, if single sheet flangeboard is used or 14 point grade minimum if double sheet flangeboard is used.
CRSC § 6-26 Medium relevance — show source text
HISTORY:
- Repealer filed 6-26-79; effective thirtieth day thereafter (Register 79, No. 26).
RELEASE OF INFORMATION
Sec. 12-13-1562.
Persons submitting information to the Commission who wish information to be kept confidential shall comply with the provisions of Sections 2501-2511 of the Public Resources Code.
Authority: Section 25218(e), Public Resources Code.
Reference: Sections 25223 and 25921.1, Public Resources Code.
HISTORY:
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
LIABILITY
Sec. 12-13-1563.
Nothing in this article shall be construed as imposing responsibility on manufacturers for misuse of properly labeled insulation.
Authority: Section 25218(e), Public Resources Code.
Reference: Sections 25926 and 25931, Public Resources Code.
HISTORY:
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
INSULATING EXISTING BUILDINGS
Sec. 12-13-1564.
(a) On or after March 25, 1982, if insulating material is installed in an existing building, in any of the applications specified in California Code of Regulations, Title 24, Part 6, Section 118, the installing contractor shall certify that the amount of insulation installed meets or exceeds the requirements of Part 6, Section 118 for that application. Such certification shall be made on completion of the installation by posting in a conspicuous location a certificate signed under penalty of perjury. The certificate shall state the manufacturer’s name and material identification, the thermal resistance ( R -value) of the newly installed insulation, the estimated R -value of the original insulation, the total R -value, and (in application of loose fill insulation) the minimum contractor installed weight per square foot. This installed weight per square foot shall conform with the manufacturer’s installed design density per square foot at the manufacturer’s labeled R -value.
(b) Water heater insulation kits. No water heater insulation kit shall be sold, on or after March 25, 1982, unless it has a thermal resistance of at least R-6 and is so identified.
Each water heater insulation kit sold shall include instructions which are equivalent to the Department of Energy standard practice for the installation of insulation on gas-fired, oil-fired and electric resistance water heaters, 44 Fed. Reg. pages 64703-64705.
Authority: Section 25922, Public Resources Code.
Reference: Section 25922, Public Resources Code.
HISTORY:
- Amendment filed 8-10-81; designated effective 9-22-81 (Register 81, No. 33).
- Editorial correction of subsection (a) filed 1-13-82 (Register 82, No. 2).
INTERPRETATION
Sec. 12-13-1565.
The General Counsel of the Commission shall make a determination as to the application or interpretation of any provision of this article to any person requesting such a determination. Any such request shall be submitted in writing to the Commission. The Commission shall make written replies to such inquiries and shall widely publish interpretations that have broad application or interest.
Authority: Section 25218 (e), Public Resources Code.
Reference: Sections 25920 and 25922, Public Resources Code.
California Referenced Standards Code Medium relevance — show source text
Can ADUs serve to qualify a project for a density bonus pursuant to State Density Bonus Law (SDBL), even though the general plan designation on the site allows less than five primary units? Yes. A project initially qualifies under the SDBL when the project’s “total units,” as defined in the SDBL (i.e., the number of units in the project before a density bonus is received) meet or exceed five units (Gov. Code, § 65915, subd. (o)(8)). Although the SDBL makes no mention of ADUs in its text, it likewise does not expressly narrow the definition of unit to exclude ADUs. Provided they are counted within the total units of the project, ADUs are a type of housing unit that may be counted for the purposes of achieving the five total unit minimum.
If ADUs can be used to qualify a project under the SDBL’s minimum total unit requirement, can they likewise be used to calculate a density bonus? No. The calculation of a density bonus is based solely on a site’s maximum allowable residential density, which does not include ADUs. A density bonus is defined as “a density increases over the otherwise maximum allowable gross residential density…” (Gov. Code, § 65915, subd. (f)). Maximum allowable residential density is defined as “the greatest number of units allowed under the zoning ordinance, specific plan, or land use element of the general plan.” (Gov. Code, § 65915, subd. (o)(6).) As an example, if the zoning ordinance allows up to two units and the general plan allows up to three, the applicable maximum allowable residential density (i.e., base density) on the site is three units, even though the addition of two ADUs brings the total units to five (see question above). The density bonus would then be calculated on top of a base density of three units, not five.
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Can a local government apply design and development standards? Yes. With an adopted ADU ordinance in compliance with State ADU Law, a local government may apply objective development and design standards that include, but are not limited to, parking, height, setback, landscape, architectural review, maximum size of a unit, and standards that prevent adverse impacts on any real property that is listed in the California Register of Historical Resources. These standards must be objective to allow ministerial review of an ADU. (Gov. Code, §§ 66314, subd. (b)(1); 66316.) ADUs created under Government Code section 66323 shall not be subject to design and development standards except for those that are specified in section 66323. (Gov. Code, § 66323, subds. (a), (b)).
Can an ADU be built in a historic district or if the primary residence is subject to historic preservation? Yes. ADUs are allowed within a historic district and on lots where the primary residence is subject to historic preservation. State ADU Law allows for a local agency to impose standards that prevent adverse impacts on any real property that is listed in the California Register of Historical Resources. (Gov. Code, § 66314, subd. (b)(1).)
As with non-historic resources, an agency may impose objective standards that do not unreasonably restrict the creation of ADUs (Gov. Code, § 66311). Local agencies are encouraged to incorporate these standards into their ordinances and to submit these standards along with their ordinances to HCD.
CRSC § 2306.2 Medium relevance — show source text
For Case 1 through 6 descriptions see Figure 2306.2(1).|For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
a. For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table for Structural I panels (regardless of
actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
b. Space fasteners maximum 12 inches on center along intermediate framing members (6 inches on center where supports are spaced 48 inches on center).
c. Framing at adjoining panel edges shall be 3 inches nominal or wider.
d. Staples shall have a minimum crown width of7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.
e. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.
f. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table shall be multiplied by 0.63 or 0.56, respectively.
g. For Case 1 through 6 descriptions see Figure 2306.2(1).|For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
a. For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table for Structural I panels (regardless of
actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
b. Space fasteners maximum 12 inches on center along intermediate framing members (6 inches on center where supports are spaced 48 inches on center).
c. Framing at adjoining panel edges shall be 3 inches nominal or wider.
d. Staples shall have a minimum crown width of7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.
e. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.
f. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table shall be multiplied by 0.63 or 0.56, respectively.
g. For Case 1 through 6 descriptions see Figure 2306.2(1).|For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
a. For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table for Structural I panels (regardless of
actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
b. Space fasteners maximum 12 inches on center along intermediate framing members (6 inches on center where supports are spaced 48 inches on center).
c. Framing at adjoining panel edges shall be 3 inches nominal or wider.
d.CRSC § 12-01 Medium relevance — show source text
An equipment pad SHALL NOT be placed on an elevated berm, mound or structure either earthen or otherwise when placed in a Flood Plain. If local knowledge of the area in which the equipment is to be placed identifies a high likelihood that uninsulated terminals of the equipment will come in contact with floodwater and the location cannot be moved to a location less likely to have flood levels come in contact with the exposed terminals, a Subsurface Fully Insulated Device should be installed in lieu of the pad mount design. In some cases such as transformers, because of capacity limits of subsurface material coded equipment it may not be possible to provide a transformer of sufficient capacity to serve loads in excess of the capabilities of a 1000 kVA UCD.
The transformer pad shall be placed on firm, compacted native material or on engineered fill which has been compacted at least to the requirements of Note 14.
Rev. #13: 12-01-19 045292 Page 1 of 8
UG-1: Transformers Greenbook Concrete Pad for Three-Phase, Loop-Style, Pad-Mounted Transformers
The area under the pad shall be excavated to the required grade, or to a depth necessary to reach firm, undisturbed material, whichever is deeper. The material can be considered firm if it cannot be penetrated by thumb except with moderate effort.
If firm material has not been reached within a depth of 3 feet, excavate 3 feet beyond the perimeter of the pad and backfill the entire excavated area to the required grade and to the requirements of Note 14.
In case it has been necessary to excavate deeper than the required grade to reach firm material, backfill to the required grade in one of the following ways:
A. Backfill with clean, non-expansive soil compacted to 90% of maximum density. Soil shall be placed in layers not more than 8 inches thick before compaction. Maximum density and in-place density is to be determined by California Test Method No. 216-G, Part I and II respectively, or by ASTM D-1556 and ASTM D-1557 respectively. A copy of the test results may be required by PG&E.
B. Backfill with soil-cement slurry consisting of one sack of Portland cement per cubic yard and clean native soil or sand. When slurry is used as a backfill material, the customer will not be required to use a poured-in-place pad.
In areas of known soft soil conditions, trenches within the pad excavation area for the installation of conduits shall be backfilled in one of the ways specified in Note 14 on Page 2.
In addition to the above, precast pads shall be placed on a 3-inch layer of slurry backfill or sand screeded level to provide uniform bearing.
Conduit windows shall be grouted with non-shrink grout (asphalt or blacktop is not approved for grouting).
CRSC § 1-2 Medium relevance — show source text
CHAPTER TOPICS Col2 CHAPTER SUBJECT 1-2 Administration and Definitions 3-4 Wildland-Urban Interface Area Designation and Requirements 5 Building Construction Regulations 6 Fire Protection Requirements 7 Referenced Standards Appendices A-I Adoptable and Informational Appendices Chapter 1 Scope and Administration.
Chapter 1 establishes the limits of applicability of the code and describes how the code is to be applied and enforced. The provisions of Chapter 1 establish the authority and duties of the code official appointed by the authority having jurisdiction and also establish the rights and privileges of the design professional, contractor and property owner.
Chapter 2 Definitions.
Chapter 2 is the repository of the definitions of terms used in the body of the code. The user of the code should be familiar with and consult this chapter because the definitions are essential to the correct interpretation of the code and because the user may not be aware that a term is defined.
Chapter 3 Wildland-Urban Interface Areas.
Chapter 3 provides for the fundamental aspect of applying the code—the legal declaration and establishment of wildland-urban interface areas within the adopting jurisdiction, mapping of the area, periodic review and updates.
Chapter 4 Wildland-Urban Interface Area Requirements.
The requirements of Chapter 4 apply to all occupancies in the wildland-urban interface and pertain to all of the following:
Fire service access to the property that is to be protected, including fire apparatus access roads and off-road driveways.
Premises identification.
Key boxes to provide ready access to properties secured by gated roadways or other impediments to rapid fire service access.
Fire protection water supplies, including adequate water sources, pumper apparatus drafting sites, fire hydrant systems and system reliability.
Fire department access to equipment such as fire suppression equipment and fire hydrants.
Chapter 5 Special Building Construction Regulations.
The regulations in Chapter 5 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 Califor- nia 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.
Chapter 6 Fire Protection Requirements.
Chapter 6 contains additional requirements for development and construction in Local Responsibility Areas (LRA) designated as Very High Fire Hazard Severity Zones and areas designated by the State Fire Marshal as State Responsibility Areas (SRA). While many of these provisions are found in Title 14 and Title 19 of the California Code of Regulations, they are replicated here for the code user. The local jurisdiction has the authority to apply the same regulations to LRA when the regulations are adopted by local ordinance.
The requirements in this chapter reference the process for adoption of Very High Fire Hazard Severity Zones in the LRA; criteria for evaluating existing subdivisions that are at significant fire risk and are without an adequate secondary egress; and criteria for fire safety provisions required in the Safety Element of a city or county General Plan.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE xi
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
Frequently asked questions
What exactly must a manufacturer show to claim an “installed design density”?
The manufacturer must demonstrate that the density chosen for loose‑fill (non‑cellulose) insulation results in settlement ≤ 2% in 3 years or ≤ 4% in 15 years; that density is the IDD used for testing and must be documented and shown on container marking and installation guidance (§ 12-13-1552(f)) .
Does “exposed application” mean outdoors?
No. “Exposed application” in this Article specifically means an interior application where the insulation’s facing or membrane is not held in substantial contact with a Chapter‑8 CBC material; it’s about the assembly and contact conditions, not exterior vs. interior location (§ 12-13-1552(e)) .
Who is responsible for labeling and IDD documentation?
The manufacturer (not an installer who only installs) is responsible for determining IDD, performing or providing test data, and marking containers with IDD, minimum thickness, maximum coverage and installation recommendations as required by the Article (§ 12-13-1552(h) and related labeling rules) .
If a facing gives a flame spread >25, what must be done?
If a product with facings/membranes has a flame spread over 25 when tested with the facings exposed, the product must be clearly labeled that it may be highly combustible if used in an exposed application, and that labeling relies on the Article’s exposed application definition (§ 12-13-1552(e) and labeling provisions) .
Are tests always done at the installed design density?
Yes for loose‑fill (non‑cellulose): the Article requires that density be used for determining density‑sensitive tests and that tests be conducted at the manufacturer’s installed design density; the Article also requires representative thickness testing in many cases .
More in California Referenced Standards Code
- Administration and scope — CRSC Chapter 12 overview
- Air filter standards (Chapter 12‑71)
- Building and facility access / accessibility standards (Chapters 12‑11A, 12‑11B)
- Engineering regulations — quality and design of construction materials (12‑16 series)
- Exits and means of egress (Chapters 12‑10 series)
- Protective signaling systems and detectors (Chapters 12‑72‑1, ‑2, ‑3)
- Radiation shielding standards (Chapter 12‑31C)
- Referenced standards index / cross‑reference table (Part 12 listing of referenced standards)
- Releasing systems for security bars (egress-release standards)
- Standards for insulating materials (Chapter 12‑13)
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