4411.94.00.10 - Impregnated with bitumen

This HTS classification, 4411.94.00.10, specifically covers fiberboard of wood or other ligneous materials, whether or not bonded with resins or other organic substances, which is of a density not exceeding 0.5 g/cm³, and more precisely, of a density exceeding 0.35 g/cm³ but not exceeding 0.5 g/cm³. The defining characteristic of this particular subcategory is that the fiberboard is **impregnated with bitumen**. This impregnation confers specific properties, such as increased water resistance and durability, distinguishing it from untreated or differently treated fiberboards.

This category stands apart from its sibling, 4411.94.00.20, which is designated for "Other" fiberboards falling within the same density range. Therefore, the key differentiator for goods classified under 4411.94.00.10 is the presence of bitumen impregnation, a treatment not applicable to the "Other" category. Classification relies on verifying the material composition and the application of bitumen as a treatment agent to the fiberboard.

As this is a leaf node within the HTS structure, there are no further subcategories to introduce. Classification decisions within this HTS code should focus on confirming that the fiberboard meets the specified density parameters (exceeding 0.35 g/cm³ but not exceeding 0.5 g/cm³) and that it has been treated or impregnated with bitumen. Examples of goods that might fall here include certain types of roofing felt backing, underlayment materials, or specialized construction boards designed for moisture resistance.