The abrasive sequence depends on the accepted timber, existing finish and intended next product. A single aggressive pass is not a universal solution. The quote should identify the preparation goal rather than promise removal of every deep mark at any cost to the boards.
Identify the previous coating where possible and show peeling, glossy or stained areas. Different finishes affect the preparation method. Unknown or suspect hazardous coatings are excluded; a sanding enquiry does not authorise stripping every old surface regardless of its composition.
Show screws or nails sitting above the surface. Suitable ordinary fixing preparation may be needed before sanding can proceed. Damaged or unsupported boards need review, and simply driving fixings deeper should not be assumed to resolve deterioration beneath the deck surface.
Prepare and sand accepted sound boards with appropriate abrasive stages and dust control, within the agreed accessible area. Scope limits: Sound ordinary accessible boards only. No structural restoration, rot concealment, hazardous coating removal, asbestos or specialist dust remediation.