Glossary
One meaning per word. Link the first use in an article. This dictionary is how we expand vocabulary without calling the same thing approved, listed, and code-compliant in three sentences.
| Term | Meaning |
|---|---|
| adopted code | The building code in force for a lot, such as ORSC R327 where a city adopted it, or California CWUIC in mapped areas. |
| assembly | The combination of parts as tested or installed, such as a roof covering plus underlayment plus deck. A covering alone is not an assembly. |
| authority having jurisdiction | The building official or other officer who interprets adopted code and issues the permit. FireApproved is not the AHJ. |
| burning brand | A specified wood crib used as the fire source in roof and some deck tests. ASTM E108 Class A, B, or C names brand size. It is not a Class A bag of shingles. |
| Chapter 7A | Historical name for California WUI construction rules. As of 1 January 2026 the live book is CWUIC. People still search Chapter 7A. |
| Class A | The most severe roof-assembly class under ASTM E108 or UL 790. Oregon R327’s floor is Class B. IBHS Essential asks for Class A. |
| Class B | The middle roof-assembly class under ASTM E108 or UL 790. Oregon R327’s floor is Class B equivalent. Class B is not Class A. |
| conflict | A computed plant status when independent evidence lineages disagree and no honest majority remains. The dissent stays on the page. We do not average the lists into a fake middle. |
| covering | The visible outer layer, such as shingles on a roof or cladding on a wall. Class A, B, and C describe a tested assembly, not a bag of covering. |
| CWUIC | California Wildland-Urban Interface Code, Title 24 Part 7, in force 1 January 2026. The live California book. Chapter 7A is the old search name. |
| defensible space | Managed vegetation and materials around a structure, often in 0–5, 5–30, and 30–100 foot bands. Zone 0 is the first band, next to the house. |
| dual-pane | Two or more lites in one window unit. Oregon R327 treats multilayered glass as one glazing option. It is not the same as tempered glass. |
| eave | The roof overhang beyond the wall. Protect the underside. Oregon R327, where adopted, restricts soffit vents except manufactured ember-resistant vents or openings 12 feet up. |
| ember | A burning fragment carried on the wind. Embers, not a wall of flame, ignite most homes lost in wildfires. |
| ember-resistant | Meant to stop wind-blown embers. Listed vents, 1/16–1/8 inch mesh, and Zone 0 are different ember-resistant tools. The phrase is not a listing ID. |
| evaluation report | An ICC-ES Evaluation Report (ESR) is an independent evaluation of how a named product meets I-Code provisions. It is not an ESL listing and not an OSFM BML number. |
| fascia | The vertical board at the eave edge that gutters often attach to. Debris and embers collect against it. Oregon R327 excepts fascia from some projection rules. |
| fire door | A door assembly tested to a fire-protection rating, often 20 minutes. That is not the same as an OSFM 8150 WUI exterior door listing. Read the listing. |
| Fire Hazard Severity Zone | California maps Moderate, High, and Very High Fire Hazard Severity Zones. The maps measure hazard, not risk. They are not Oregon R327 and not an insurance rate map. |
| fire-retardant-treated wood | Wood treated to reduce flame spread, often listed as exterior FRT. Oregon R327 names it as one walking-surface path. It is not noncombustible and not a coating. |
| Firewise USA | An NFPA recognition program for communities that reduce wildfire risk. It is not a product listing and not adopted building code. |
| flame spread | How far flame travels across a specimen in ASTM E84. An index is not a Class A roof and is not noncombustible. Oregon ignition-resistant uses an extended run. |
| horizontal projection | A building part that sticks out, such as an eave, balcony, or patio cover. California tests the underside to SFM 12-7A-3. It is not a vent. |
| ignition-resistant | A material or assembly that meets a named fire test for ignition, such as an extended ASTM E84 run in Oregon R327. It is not the same as noncombustible. |
| intumescent | A material that swells when heated and can close a gap. Some listed vents use intumescent cores. A paint-on coating is not an Oregon R327 wall covering. |
| IWUIC | International Wildland-Urban Interface Code. A model WUI code. It applies only where a jurisdiction adopts it. Oregon uses optional R327 instead of a statewide IWUIC mandate. |
| limited evidence | A computed plant label meaning one independent Tier-1 lineage is enough to classify, and that thinness is shown. It is not a third recommendation grade and not a pass. |
| listed | A named model appears on a listing body’s current record, with an ID. Listed is not approved by FireApproved and is not a permit. |
| listing body | An organization that publishes model-level listings, such as OSFM BML or ICC-ES. It is not the building official and not this site. |
| mesh | Noncombustible, corrosion-resistant metal screen with openings from 1/16 to 1/8 inch. A prescriptive ember path. Not an ASTM E2886 listed vent. |
| net free area | The unobstructed opening area a vent still provides after mesh or a listed core. Fine mesh reduces it. Size vents so the attic still meets ventilation code. |
| noncombustible | A material that does not ignite or burn in standard tests such as ASTM E136. Concrete, steel, and gravel are typical examples. It is stricter than ignition-resistant. |
| ORSC R327 | Oregon Residential Specialty Code wildfire section. It applies only where a local building department has adopted it. It is not statewide and not CWUIC. |
| OSFM | California Office of the State Fire Marshal. It runs the Building Materials Listing program. It is not Oregon’s fire marshal and not an Oregon building official. |
| performance path | A rule that accepts a tested assembly, such as an ASTM E2886 listed vent, instead of a named mesh size. |
| prescriptive path | A rule that names materials or sizes, such as 1/16–1/8 inch metal mesh on a vent. You follow the recipe. You do not submit a lab report for that piece. |
| radiant heat | Heat transferred through the air without flame contact. It can break glass and ignite surfaces before flame arrives. It is not ember ignition. |
| soffit | The finished underside of an eave or other overhang. OSFM 8160 lists underside coverings. Perforated soffit is not an ember-resistant vent. |
| spark arrester | Noncombustible corrosion-resistant metal mesh on a chimney or stovepipe outlet. CAL FIRE’s low-cost list names 3/8- to 1/2-inch openings. It is not an ember-resistant wall vent. |
| tempered | Glass heat-treated so it resists breaking better than annealed glass. California CWUIC wants at least one tempered pane in dual-pane units. Tempered is not dual-pane. |
| test method | A laboratory procedure such as ASTM E2886 or ASTM E108. A pass is a result for a specimen, not a permit for your lot. |
| Type X | Gypsum board with a fire-resistance core used as a deemed-to-comply layer behind cladding. Type X is an assembly path. It is not an ASTM E136 pass for the visible siding. |
| wildland-urban interface | Where houses and wildland vegetation meet or mix. WUI is a land condition. It is not by itself a product listing. |
| Zone 0 | The first five feet from exterior walls and attached decks. Keep it largely noncombustible. It is not a planting palette. |
| Zone 1 | The defensible-space band often 5–30 feet from walls. Fire-resistant plants belong here, not in Zone 0. It is not a Zone 0 spec. |
| Zone 2 | The outer defensible-space band, often 30–100 feet from the house. Reduce fuel continuity. Plants here are not a Zone 0 product. |