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Spray-applied FRT and special inspection
Spray-applied fire retardant is not a numbered R327 wall covering. Presenters at the 25 June 2026 Central Oregon seminar said it may need a third-party special inspector the jurisdiction has approved. That inspector reports to the jurisdiction. Coatings are not accepted to meet R327. Factory fire-retardant-treated wood is a different product.
You are looking at a wet spray on wood. The official may want a third-party report before calling it done. That is not the Type X firewall inspection, and it is not a can of paint.
Why it matters
People hear “fire retardant” and reach for a sprayer. R327.3.3 does not list coatings. The seminar said coatings are not accepted. If a job still uses spray-applied retardant on an element the official will accept, the seminar named a special inspection path. Mixing those three sentences is how a drawing gets redlined.
How the seminar split it
On 25 June 2026, City of Bend Building Safety and Deschutes County Community Development presented inspections:
| Hold point | When | Not |
|---|---|---|
| Firewall inspection | 5/8 inch Type X behind finish, gypsum in, screws in, before covering | Spray FRT |
| Special inspection | May be required for spray-applied fire retardant. Inspector approved by the jurisdiction. Report back to the jurisdiction. | A paint-can spec |
| Framing / final | Most other R327 items | A substitute for the two hold points above |
That is event testimony. Confirm with the building official. It is not a BCD ruling.
The paths
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Do not coat the wall. R327.3.3 is noncombustible, ignition-resistant, heavy timber, log, ASTM E2707, or Type X / one-hour exceptions. See ignition-resistant versus noncombustible and the coatings finding.
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Factory exterior FRT wood. R327.3.5 names exterior fire-retardant-treated wood as one walking-surface path. That is a treated board, not a field spray. Weathering and listing still matter. This page does not spec AWPA retreatment.
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If spray-applied retardant is still on the job. Ask the official whether a special inspector is required. If yes, the seminar said that person is approved by the jurisdiction, inspects the installation, and files a report. Put the product and the inspection on the drawings. See show the product on the drawings.
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Type X. Different path, different inspection. See Type X behind the covering.
What people mix up
- Spray-on coating as ignition-resistant siding.
- Factory FRT deck boards as a field spray.
- The Type X firewall inspection as the spray-FRT special inspection.
- Treating seminar practice as a BCD bulletin.
How to check
- Read the adopted code. If the element is a wall, coatings are not on the list.
- If the drawing shows spray-applied retardant, ask the official about special inspection before you spray.
- Name the inspector the jurisdiction will accept. Get the report into the file.
- Do not hide the product behind “treated wood.”
Limits
This page does not approve a spray product. It does not quote private email. It does not spec factory FRT process. Event testimony is dated 25 June 2026. FireApproved is not the AHJ.
Related records
Questions
Can I spray a fire coating on wood siding and call it R327?
No. Coatings are not on the R327.3.3 wall list. Presenters at the 25 June 2026 seminar said coatings are not accepted to meet R327. That is a different sentence from factory fire-retardant-treated wood.
When is a special inspector required?
Presenters said third-party special inspectors may be required for elements such as spray-applied fire retardant. The inspector has to be approved by the jurisdiction, inspects the installation, and gives a report to the jurisdiction. That is event testimony, not a BCD ruling. Confirm with the official.
Is factory FRT the same as spray-applied retardant?
No. Oregon R327 names exterior fire-retardant-treated wood as one walking-surface path. That is a treated product. Spray-applied retardant on site is what the seminar flagged for special inspection. Do not swap the words.
Does Type X skip this inspection?
Type X behind the covering is a different path. Presenters named a firewall inspection for that gypsum method. Do not treat the Type X hold point as the spray-FRT special inspection.