Description: This industry comprises establishments primarily engaged in building foundation and structure trades work (except poured concrete, structural steel, precast concrete, framing, masonry, glass and glazing, roofing, and siding). The work performed may include new work, additions, alterations, maintenance, and repairs. Illustrative Examples: Curtain wall, metal, installation Forms for poured concrete, erecting and dismantling Welding, on-site, contractors Ornamental metal work installation Fire escape installation Decorative steel and wrought iron work installation Cross-References. Establishments primarily engaged in--