- Plumbing, heating, air-conditioning (3)
- Electrical work (2)
- Masonry and other stonework (1)
- Carpentry work (1)
- Roofing, siding, and sheetmetal work (1)
- Concrete work (2)
- Structural steel erection (1)
- Excavation work (1)
- Special trade contractors, nec (2)
