Thermally Modified Ash Americana and *Red *Oak Siding

The construction described in CAL FIRE listing 8140-2308:0501 uses nominal 1-by-6-inch material with a maximum 1-inch shiplap. Both qualifications matter when comparing profiles: the board size is nominal, and the shiplap dimension is an upper limit. The named horizontal installation is part of this listing's scope.

OSFM identifies SFM 12-7A-1 as the test protocol for the siding entry. That protocol reference belongs to this exterior-wall product; it does not extend the listing to a different board size, joint arrangement or installation direction. The wood species and thermal modification identify the product, while the dimensions and orientation identify the construction being cited.

For a specification, match the supplier's exact siding profile to the nominal board size and shiplap limit, then follow the manufacturer's installation instructions and product data sheets. Confirm listing 8140-2308:0501 in GOVmotus before relying on it. This gives the purchaser a concrete horizontal-wall assembly to check, rather than treating any thermally modified ash or red oak as equivalent.