Findings

IBHS Wildfire Prepared Home requires a 0–5 foot noncombustible zone. The technical standard requires removal of combustible groundcover, including wood and rubber mulch, to bare mineral soil. Bark, wood chips, and rubber mulch in that band fail Essential.

CAL FIRE home-hardening guidance tells homeowners to keep the area beneath a deck and the first five feet around it clear of combustible material and to use hardscape in that zone. This is California mitigation guidance, not a construction-code application or an IBHS designation.

R327.3.4.1 requires protection of the exposed underside of rafter or truss eaves and enclosed soffits when any portion of the framing is under 12 feet. Exception 3 names fascia and other architectural trim boards. Wrapping fascia as if it were the eave assembly is not what that section requires. Confirm the drawing with the building official.

Oregon BCD’s local-adoption FAQ states Section R327 applies only to structures governed by the ORSC. Manufactured dwellings are factory-built to federal HUD standards and an Oregon installation code. They are not under ORSC scope. Deschutes County repeats that manufactured dwellings are not applicable. A wildfire package from a manufacturer is optional, not R327.

Oregon State Fire Marshal defensible-space guidance tells homeowners to use river rock, gravel, or pavers within five feet of the structure and to remove bark mulch from that buffer. This is statewide mitigation guidance, not an ORSC R327 application.

Deschutes County’s R327 page states R327 provides no code requirements for stair assemblies to elevated decks or landings, and that BCD treats those stairs as exempt. Walking-surface and underfloor rules for the deck are separate sentences. Do not copy the deck-board test onto the stair stringer without the official.

OSFM category 8110 lists named Trex Transcend models under listing IDs 8110-2052:0004, 8110-2052:0005, and 8110-2052:0501. Those rows are specific boards, thickness, edge, and gap. Writing “Trex” on a drawing is not those IDs. This finding does not say Trex is banned. Match the listing ID and the R327 walking-surface path. Confirm with the building official.

Screening laid horizontally under deck boards does not close the ember path from the side. The IBHS Wildfire Prepared Home standard calls for corrosion-resistant metal mesh to fully enclose the outer edge of the space beneath a deck down to the ground.

Perforated or louvered fiber-cement soffit panels are a cladding product. They are not a substitute for 1/16–1/8 inch noncombustible mesh or an ASTM E2886 listed vent where eave ventilation is allowed. Deschutes County’s R327 page flags soffits under 12 feet as a protected assembly.

Where Oregon R327 is adopted, roofing must be asphalt, slate, metal, tile, clay or concrete shingles, or other approved covering deemed equivalent to a minimum Class B roof assembly. Wood shingle and shake roofs are not permitted on structures in the designated area.

ORSC R327 lists noncombustible, ignition-resistant, heavy timber, log, or tested wall assemblies. Paint-on fire coatings are not in that list. Presenters at the 25 June 2026 Central Oregon Fire Hardening Codes Seminar stated coatings are not accepted to meet R327. Confirm with the local building official.

R327.3.2 allows underfloor ventilation openings to be covered with noncombustible corrosion-resistant metal wire mesh between 1/16 inch and 1/8 inch, or with vents designed to resist burning embers and flame, or other approved materials. Mesh is a sized screen, not ASTM E2886. Presenters at the 25 June 2026 Central Oregon seminar stated foundation vents need screen size, not an ember-intrusion test. Eave underside openings are a different sentence.

R327.3.2 covers ventilation openings for enclosed attics, enclosed soffit spaces, enclosed rafter spaces, and underfloor spaces. It names mesh size or vents designed to resist burning embers and flame. It does not name bath fans, fireplaces, or fresh-air intakes. Presenters at the 25 June 2026 Central Oregon Fire Hardening Codes Seminar stated those mechanical openings sit outside that section. Confirm with the building official.