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The wall base and the six-inch band
The bottom of the wall is two documents. Where Oregon R327 is adopted, R327.3.3.1 runs the covering from the top of the foundation to the roof. It does not name a six-inch noncombustible band (amendment PDF). IBHS Wildfire Prepared does. It wants at least six inches of noncombustible material from grade and from the nearest horizontal surface, including decks. Do not write the IBHS number onto the Oregon sentence.
You are at the mudsill. Fiber-cement, concrete, or wood siding dies at grade, or it hangs over a deck. Embers and splash sit there.
The wall-bottom drawing (DET-016) is not published yet. Termination at the eave lives on wall covering termination. Do not use a house-level hub graphic as this base.
Why it matters
Embers and ignited mulch attack the first course. IBHS treats that course as a designation item. Oregon treats the covering as a full-height path plus a stop at blocking or the soffit. Mixing the two produces a six-inch band that is not in R327.3.3.1, or a full-height covering that still fails IBHS.
How the rules split
| Document | What it says at the base | What it does not say |
|---|---|---|
| R327.3.3.1 | Covering from top of foundation to roof | A six-inch noncombustible skirt |
| R327.3.3 | The covering or assembly menu | IBHS’s six inches |
| IBHS Base | ≥ 6 inches noncombustible from grade and from the nearest horizontal surface | An Oregon code section |
| FEMA P-737 | Bottom two to three courses, or 18-inch flashing at a deck; flashing at the bottom of all claddings | A listing ID |
The paths
1. Oregon covering. Pick an R327.3.3 path. Run it the full height. See wall covering termination and Type X.
2. IBHS six inches. Concrete, fiber-cement, brick, stone, stucco, or metal flashing, measured from grade and from the deck. Posts too.
3. Deck ledger. The nearest horizontal surface is often the deck. See deck ledger.
4. FEMA retrofit. Replace bottom courses, or 18-inch flashing at the deck tucked behind siding. Guidance, not R327.
What people mix up
- Writing six inches onto R327.3.3.1.
- Treating a weep screed as the wildfire band.
- Scoring IBHS without measuring from the deck.
- Stopping the covering at four feet and calling the rest trim.
How to check
- Confirm whether R327 is adopted and whether you are scoring IBHS.
- Look at the first course. Name the covering path.
- If IBHS, measure six inches from grade and from the deck.
- Do not put a six-inch note on an R327.3.3.1 detail unless the official asked for IBHS too.
Limits
DET-016 is not published. This page does not spec a weep. FireApproved is not the AHJ. IBHS is a designation.
Related records
Questions
Does Oregon R327 require six inches of noncombustible wall at grade?
No. R327.3.3.1 requires covering from the top of the foundation to the roof, ending at 2-inch blocking or the underside of an enclosed soffit. It does not name a six-inch band. IBHS measures at least six inches of noncombustible covering from grade and from the nearest horizontal surface, including decks.
If I have a deck, where do I measure the six inches?
IBHS measures from the ground at grade and from the nearest horizontal surface, for example decks and patios. Combustible deck posts get the same six inches. That is designation language, not R327.3.3.1.
Is a weep screed the six-inch rule?
No. Weep screeds and moisture details are not this wildfire sentence. DET-016 is not published. Do not invent a six-inch R327 base from stucco practice.