|
| 4520 | Cleaning railroad ballasts | |
| 4520 | Clinics, medical, construction | |
| 4520 | Coal treating plants, construction | |
| 4520 | Coating and sealing driveways and parking areas | |
| 4520 | Coating and sealing roofs (except shingling) | |
| 4520 | Cofferdams, construction | |
| 4520 | Coke oven construction, general contractors | |
| 4520 | Cold storage plant construction, general contractors | |
| 4520 | Commercial buildings, construction | |
| 4520 | Commercial developer | |
| 4520 | Commercial warehouse construction, general contractors | |
| 4520 | Communication towers, construction | |
| 4520 | Compressor, metering and pumping stations, gas and oil, construction | |
| 4520 | Concrete block laying, contractors | |
| 4520 | Concrete construction (e.g., roads, highways, public sidewarlks, streets), general contractors | |
| 4520 | Concrete drilling and cutting | |
| 4520 | Concrete finishing, contractors | |
| 4520 | Concrete floor finishing | |
| 4520 | Concrete forming, contractors | |
| 4520 | Concrete forms, placing and stripping | |
| 4520 | Concrete framing | |
| 4520 | Concrete grinding and polishing | |
| 4520 | Concrete placing or placement | |
| 4520 | Concrete plumbing (water and sewer work), construction | |
| 4520 | Concrete pouring | |
| 4520 | Concrete products, structural precast or prestressed, installation | |
| 4520 | Concrete pumping (placement) | |
| 4520 | Concrete reinforcement placement, contractors | |
| 4520 | Concrete repairs | |
| 4520 | Concrete rotary trowelling | |
| 4520 | Concrete sawing | |
| 4520 | Concrete work, private driveways, sidewalks and parking areas, contractors | |
| 4520 | Condominium developers | |
| 4520 | Condominium, row housing, single residential, construction | |
| 4520 | Conduit construction, contractors | |
| 4520 | Constructing buildings on site (stick building) | |
| 4520 | Construction administration services | |
| 4520 | Construction administrator services | |
| 4520 | Construction co-ordination, supervision and management services | |
| 4520 | Construction elevator, erection and dismantling | |