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FA Exhibit MECH-009

Char front on 2x vs 6x at 1.5 in/hr nominal (E119 clock, NTS)

At the one-hour AWC FDS reference point, four-side cross-sections show a nominal 1.5-inch char depth consuming the narrow dimension of a 2x4 while leaving a core in a 6x6. A separate dashed line marks the 1.8-inch effective char depth used for structural section properties. This is an NTS furnace-clock comparison, not a wildfire claim or rating.
FA Exhibit MECH-009. Char front on 2x versus 6x. AFTER AWC FDS 2024 §§3.1–3.3 + TABLES 1.5.4 / 3.3.1.2 · ORIGINAL LINE ART. Illustrative — not a construction document. Verify with your building official. CC BY 4.0.

Technical review: Grayson Graham. Last verified 2026-08-25. JSON

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<img src="https://fireapproved.com/diagrams/mech-009-char-front-2x-vs-6x.svg" alt="At the one-hour AWC FDS reference point, four-side cross-sections show a nominal 1.5-inch char depth consuming the narrow dimension of a 2x4 while leaving a core in a 6x6. A separate dashed line marks the 1.8-inch effective char depth used for structural section properties. This is an NTS furnace-clock comparison, not a wildfire claim or rating." />

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