This NAICS Industry Group includes establishments classified in the following NAICS Industries: 42331, Lumber, Plywood, Millwork, and Wood Panel Merchant Wholesalers; 42332, Brick, Stone, and Related Construction Material Merchant Wholesalers; 42333, Roofing, Siding, and Insulation Material Merchant Wholesalers; and 42339, Other Construction Material Merchant Wholesalers.