Yes, heading 6803 explicitly covers both worked natural slate and articles of agglomerated slate, so both product types are classified within the same heading. However, commercial invoices should clearly identify whether the product is natural or agglomerated, as the distinction may be relevant to building-code compliance documentation required by the buyer.

Roofing slate demand tracks construction and re-roofing activity, which peaks in spring and early fall in most US markets. Importers typically build inventory ahead of the spring construction season, and ocean transit times from Spain — the dominant supplier — of roughly two to four weeks factor into order lead times. Weather-related port disruptions in northern European winter months can also affect supply timing.