Bitumen-Impregnated Low-Density Fiberboard Sheathing Panels from Japan

These are low-density fiberboard panels (density ≤0.5 g/cm³) made from wood fibers, impregnated with bitumen for water resistance, used primarily as exterior sheathing in construction. They fall under HTS 4411.94.0050 because they are not mechanically worked or surface-covered beyond the bitumen impregnation, meeting the specific criteria for this subheading. The bitumen treatment provides essential protection against moisture without altering the base material's classification.