19 building materials; namely, lumber, plywood, wood beams, wallboards, wood and/or vinyl siding, cement mix, plaster, spackling compound; pre-fabricated structures; namely, garages, homes, cottages, decks, screened-in porches, pre-fabricated wood trusses, gable ends, arch ribs; floor coverings; namely, wood tile and materials used in connection therewith, sold as a unit