This industry includes lumber, plywood, millwork, wood panel, brick, stone, roofing, siding and insulation material merchant wholesalers. Lumber, plywood, millwork and wood panel merchant wholesalers sell lumber, plywood, wood fiber products, wood fencing, doors and windows for frames and wood millwork. Brick, stone and related construction material merchant wholesalers sell stone, cement, lime, construction sand, gravel and concrete. Roofing, siding and insulation material merchant wholesalers sell non-wood roofing and non-wood siding and insulation materials. Examples of merchant wholesalers in this industry are flat glass merchant wholesalers, wire fencing merchant wholesalers and ornamental ironwork merchant wholesalers.