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Standards / ASTM E2632
ASTM E2632
Under-deck fire-test method for walking-surface materials. Heat-release and decomposition under a burner that simulates combustibles burning beneath a deck. Not SFM 12-7A-4 and not a permit.
Covers: Fire-test-response of deck materials used as the walking surface when exposed from below to a laboratory burner flame.
Does not cover: A burning-brand-on-the-top-surface method treated as this test, SFM 12-7A-4, under-deck mesh as the walking-surface class, or a local installation approval.
ASTM E2632 (with E2632M) is the under-deck test method for deck walking-surface materials. A laboratory burner under the boards simulates combustibles burning beneath a deck. The method looks at heat-release rate and how the boards break down. It is not SFM 12-7A-4, not under-deck mesh, and not a permit.
Why it matters
Embers and stored fuel under an elevated deck ignite the walking surface from below. Oregon R327, where adopted, names this method in the walking-surface list. People then paste a California 8110 listing onto an Oregon job and call it done. Those are different tests.
How the test works
The active document is ASTM E2632/E2632M-20 (ASTM store record). Scope 1.1 covers deck materials used as the walking surface. The prescribed fire exposure is a burner flame under the deck. Significance 5.1 says the method addresses suitability by assessing response to fire hazards associated with sources of flame located beneath the deck material.
ASTM states the method does not, by itself, complete a fire-hazard or fire-risk assessment of the deck materials under actual fire conditions.
Sibling method, withdrawn. ASTM E2726/E2726M was a distinct burning brand method on the upper surface of a deck structure, described as a variation of Test Method E108. ASTM marks E2726/E2726M-12a(2017) withdrawn 2026 with no replacement. This site does not keep a standalone E2726 page for a withdrawn standard. Oregon’s 2023 amendment still prints both numbers. If you use R327.3.5 item 1, you still have to read that section and the reports the building official asks for.
This page does not create an E2726 listing ID or a fake live standard.
The paths
| Problem | Oregon R327 where adopted | California OSFM 8110 |
|---|---|---|
| Walking surface 30 inches to 12 feet | R327.3.5. E2632 and E2726 is one numbered item, not the only item | SFM 12-7A-4 or 12-7A-4A |
| Underfloor of an elevated deck | R327.3.4.4 enclose to grade or protect. Deschutes County states there is no 12-foot exception for that underside | Not this method |
| Wall next to the deck | R327.3.3 / ASTM E2707 | SFM 12-7A-1 |
1. Oregon walking-surface performance path. Materials that meet R327.3.5.1 when tested to both ASTM E2632 and ASTM E2726. Peak heat-release and the other conditions live in the amendment, not in this paraphrase. Open the PDF.
2. Other Oregon walking-surface paths. Ignition-resistant material, exterior fire-retardant-treated wood, noncombustible material, or E2632 material where the wall covering is noncombustible or ignition-resistant. A small-deck lumber exception exists in the amendment. Do not invent the area number from memory. Read the section.
3. California listing path. OSFM 8110 names 12-7A-4 or 12-7A-4A. Listing is voluntary for most WUI products. See OSFM BML.
4. Under-deck enclosure is not the walking-surface test. Enclosure to grade, Type X, or an ASTM E2957 assembly is R327.3.4.4. Horizontal mesh under the joists is a finding, not this method.
What people mix up
- Treating E2632 and E2726 as one method. Under-deck burner versus brand on top.
- Treating a withdrawn E2726 page as a live ASTM download. The number still appears in Oregon’s 2023 text. ASTM’s current store record is withdrawn.
- Treating an 8110 listing as R327.3.5.
- Treating generic “Trex” as a named 8110 row. Product-line-varies. Match the model.
- Copying the eave 12-foot rule onto the underfloor. Deschutes County says no.
How to check
Read the adopted walking-surface section. If you use item 1, get E2632 and E2726 reports that match the boards, spacing, and framing. If you use an OSFM 8110 model, open the product page and the listing ID. Confirm the protocol string is 12-7A-4 or 12-7A-4A, not E2632, unless the report actually says E2632.
On the house, measure height above grade, look under the deck, and note stored fuel.
Limits
This page does not decide the AHJ stamp. It does not restore a withdrawn ASTM standard. It does not rate walls, roofs, or vents. Absence from the handbook is not a ban. Presence is not a permit.
Related records
Decking, SFM 12-7A-4, R327 versus CWUIC, under-deck horizontal mesh.
Sources
- ASTM E2632/E2632M-20 (ASTM International)
- ASTM E2726/E2726M-12a(2017), withdrawn 2026 (ASTM International)
- 2023 ORSC Section R327 amendment (Oregon BCD)
- 2025 OSFM WUI Listed Products Handbook (CAL FIRE OSFM)
Is ASTM E2632 the same as ASTM E2726?
No. E2632 is the under-deck burner method. E2726 was the burning-brand method on the upper surface of a deck. ASTM withdrew E2726/E2726M-12a(2017) in 2026 with no replacement. Oregon R327.3.5 still names both numbers in the 2023 amendment. Read the adopted section and the test reports.
Is ASTM E2632 the same as SFM 12-7A-4?
No. 12-7A-4 is California’s two-part deck method (under-deck flame plus a brand on the boards). OSFM category 8110 names 12-7A-4 or 12-7A-4A. Oregon R327.3.5 names E2632 and E2726 among other paths.
Does a listed Trex model automatically meet R327.3.5?
No. An OSFM 8110 listing is a California record for a named model. Generic “Trex” is a brand line. Match the listing ID and the tests R327 names. Confirm with the building official.
Does under-deck mesh replace this walking-surface test?
No. Mesh on the vertical plane to grade is a different finding. Walking-surface class and underfloor enclosure are separate R327 sentences.