Riverhead Building Supply Corp. operates as a custom millwork shop across the United States. Based in Mineola, N.Y., it offers a range of products in the categories, including lumber/plywood, windows/doors, metal and cement products, kitchen/bath, flooring, roofing/siding, molding/trim and drywall/insulation. The firm caters to a number of clients, such as builders, contractors, architects and homeowners in the Long Island and New York Metropolitan area. Riverhead Building Supply Corp. has associations with the National Association of the Remodeling Industry (NARI) and Long Island Builders Institute (LIBI), to name a few.