General engineering contractors are those whose business is primarily in connection with fixed works requiring specialized engineering knowledge and skill in the following areas: irrigation, drainage, water power, water supply, flood control, inland waterways, harbors, docks and wharves, shipyards and ports, dams and hydroelectric projects, levees, river control and reclamation works, railroads, highways, streets and roads, tunnels, airports and airways, sewers and sewage disposal plants and systems, waste reduction plants, bridges, overpasses, underpasses and other similar works, pipelines and other systems for the transmission of petroleum and other liquid or gaseous substances, parks, playgrounds and other recreational works, refineries, chemical plants and similar industrial plants requiring specialized engineering knowledge and skill, powerhouses, power plants and other utility plants and installations, mines and metallurgical plants, land leveling and earthmoving projects, excavating, grading, trenching, paving and surfacing work, and cement and concrete works in connection with the above mentioned fixed works.

A general building contractor’s primary business relates to any structure built, being built, or to be built for the support, shelter, and enclosure of people, animals, chattels, or movable property and requires the use of at least two unrelated building trades or crafts. This does not include anyone who simply furnishes materials or supplies under Section 7045 without fabricating them into or consuming them in the performance of the work of the general building contractor.

More specifications about this license can be found here.

A residential remodeling contractor works in connection with any project to make improvements to, on, or in an existing residential wood-frame structure, and the project requires the use of at least three unrelated building trades or crafts for a single contract. This type of contractor may take a prime contract for trades or crafts which can include (but is not limited to) any of the following:

• Drywall
• Finish carpentry
• Flooring
• Insulation
• Painting
• Plastering
• Roof repair
• Siding
• Tiling
• Installing, repairing, or replacing electrical fixtures, such as dimmers, fans, lights, outlets, and switches
• Installing, repairing, or replacing plumbing fixtures, such as faucets, sinks, toilets, and tubs
• Installing, repairing, or replacing mechanical fixtures, such as air filters, air delivery and return grills, and preassembled exhaust fans

More specifications about this license can be found here.

A specialty contractor performs construction work requiring special skills. This type of contractor’s principal contracting business involves the use of specialized building trades or crafts. Examples of a specialty contractor’s operations may include:

• Servicing or testing fire extinguishing systems
• Installing carpets, linoleum, or resilient floor coverings
• Preparing or removing roadway construction zones, lane closures, flagging, or traffic diversion on roadways including, but not limited to, public streets, highways, or any public conveyance

The C license group includes the following sub-classifications:

• C-2 – Insulation and Acoustical Contractor
• C-4 – Boiler, Hot Water Heating and Steam Fitting Contractor
• C-5 – Framing and Rough Carpentry Contractor
• C-6 – Cabinet, Millwork and Finish Carpentry Contractor
• C-7 – Low Voltage Systems Contractor
• C-8 – Concrete Contractor
• C-9 – Drywall Contractor
• C-10 – Electrical Contractor
• C-11 – Elevator Contractor
• C-12 – Earthwork and Paving Contractors
• C-13 – Fencing Contractor
• C-15 – Flooring and Floor Covering Contractors
• C-16 – Fire Protection Contractor
• C-17 – Glazing Contractor
• C-20 – Warm-Air Heating, Ventilating and Air-Conditioning Contractor
• C-21 – Building Moving/Demolition Contractor
• C-22 – Asbestos Abatement Contractor
• C-23 – Ornamental Metal Contractor
• C-27 – Landscaping Contractor
• C-28 – Lock and Security Equipment Contractor
• C-29 – Masonry Contractor
• C-31 – Construction Zone Traffic Control Contractor
• C-32 – Parking and Highway Improvement Contractor
• C-33 – Painting and Decorating Contractor
• C-34 – Pipeline Contractor
• C-35 – Lathing and Plastering Contractor
• C-36 – Plumbing Contractor
• C-38 – Refrigeration Contractor
• C-39 – Roofing Contractor
• C-42 – Sanitation System Contractor
• C-43 – Sheet Metal Contractor
• C-45 – Sign Contractor
• C-46 – Solar Contractor
• C-47 – General Manufactured Housing Contractor
• C-50 – Reinforcing Steel Contractor
• C-51 – Structural Steel Contractor
• C-53 – Swimming Pool Contractor
• C-54 – Ceramic and Mosaic Tile Contractor
• C-55 – Water Conditioning Contractor
• C-57 – Well Drilling Contractor
• C-60 – Welding Contractor
• C-61 – Limited Specialty