ARC Mechanical Contractors

Cost estimators collect and analyze data to estimate the time, money, resources, and labor required for product manufacturing, construction projects, or services. Some specialize in a particular industry or product type.

Cost estimators typically do the following:

• Consult with industry experts to discuss estimates and resolve issues
• Identify and quantify cost factors, such as production time and raw material, equipment, and labor expenses
• Travel to job sites to gather information on materials needed, labor requirements, and other factors 
• Read blueprints and technical documents to prepare estimates
• Collaborate with engineers, architects, owners, and contractors on estimates
• Use sophisticated computer software to calculate estimates 
• Evaluate a product's cost effectiveness or profitability
• Recommend ways to make a product more cost effective or profitable
• Prepare estimates for clients and other business managers
• Develop project plans for the duration of the project

Accurately predicting the cost, size, and duration of future construction and manufacturing projects is vital to the survival of any business. Cost estimators' calculations give managers or investors this information.

When making calculations, estimators analyze many inputs to determine how much time, money, and labor a project needs, or how profitable it will be. These estimates have to take many factors into account, including allowances for wasted material, bad weather, shipping delays, and other factors that can increase costs and lower profitability.

Cost estimators use sophisticated computer software, including database, simulation, and complex mathematical programs. Cost estimators often use a computer database with information on the costs of other similar projects.

General contractors usually hire cost estimators for specific parts of a large construction project, such as estimating the electrical work or the excavation phase. In such cases, the estimator calculates the cost of the construction phase for which the contractor is responsible, rather than calculating the cost of the entire project. The general contractor usually also has a cost estimator who calculates the total project cost by analyzing the bids that the subcontractors' cost estimators prepared.

Some estimators are hired by manufacturers to analyze certain products or processes.

The following are the two primary types of cost estimators:

Construction cost estimators estimate construction work. More than half of all cost estimators work in the construction industry. They may, for example, estimate the total cost of building a bridge or a highway. They may identify direct costs, such as raw materials and labor requirements, and set a timeline for the project. Although many work directly for construction firms, some work for contractors, architects, and engineering firms.

Manufacturing cost estimators calculate the costs of developing, producing, or redesigning a company's goods and services. For example, a cost estimator working for a home appliance manufacturer may determine whether a new type of dishwasher will be profitable to manufacture.

Some manufacturing cost estimators work in software development. Many high-technology products require a considerable amount of computer programming, and the costs of software development are difficult to calculate.  

Two other groups also sometimes do cost estimating in their jobs. Operations research, production control, cost, and price analysts who work for government agencies may do significant amounts of cost estimating in the course of their usual duties. Construction managers also may spend considerable time estimating costs. For more information, see the profiles on operations research analysts and construction managers.

Computer, ATM, and office machine repairers install, fix, and maintain many of the machines that businesses, households, and other consumers use.

Computer, ATM, and office machine repairers typically do the following:

• Travel to customers' locations in response to service requests
• Communicate with customers to determine the source of a problem
• Do administrative tasks, such as completing work order forms
• Use a variety of tools, such as a multimeter, to help diagnose the problem
• Install large equipment, such as mainframe computers and ATMs
• Explain the basic functions of machines and equipment to customers
• Replace malfunctioning machine parts, such as video cards in desktop computers or keypads on ATM machines
• Provide preventative maintenance, such as cleaning the internal parts of machines
• Test newly installed systems to make sure they work properly

In most cases, machines do not break down entirely. Often just one broken part can keep a machine from working properly. Repairers often fix machines by replacing these parts and other defective equipment because it is often less expensive than replacing the entire machine.

Although the work of computer, ATM, and office machine repairers is very similar, the exact tasks differ depending on the type of equipment. For example, computer repairers often must replace desktop parts, such as a motherboard, because of hardware failure. ATM repairers may replace a worn magnetic head on a card reader to allow an ATM to recognize customers' bank cards. Office machine repairers replace parts of office machines that break down from general wear and tear, such as the printheads of inkjet printers.

Some repairers have assigned areas where they do preventive maintenance on a regular basis.

Computer repairers service and repair computer parts, network connections, and computer equipment, such as an external hard drive or computer monitor. Computer repairers must be familiar with various operating systems and commonly used software packages. Some work from repair shops, while others travel to customers' locations.

ATM repairers install and repair automated teller machines and, increasingly, electronic kiosks. They often work with a network of ATMs and travel to ATM locations when they are alerted to a malfunction.

Office machine repairers fix machinery at customers' workplaces because these machines are often large and stationary, such as office printers or copiers. Office machines often need preventive maintenance, such as cleaning, or replacement of commonly used parts as they break down from general wear and tear.

Electricians install and maintain electrical systems in homes, businesses, and factories.

Electricians typically do the following:

• Read blueprints or technical diagrams before doing work
• Install and maintain wiring and lighting systems
• Inspect electrical components, such as transformers and circuit breakers
• Identify electrical problems with a variety of testing devices
• Repair or replace wiring, equipment, or fixtures using hand tools and power tools
• Follow state and local building regulations based on the National Electric Code
• Direct and train workers to install, maintain, or repair electrical wiring or equipment

Almost every building has an electrical system that is installed during construction and maintained after that. Electricians do both the installing and maintaining of electrical systems.

Installing electrical systems is less complicated than maintaining older equipment. This is because it is easier to get to electrical wiring during construction. Maintaining older equipment, however, involves identifying problems and repairing malfunctioning equipment that is sometimes difficult to reach. Electricians doing maintenance work may need to fix or replace outlets, circuit breakers, motors, or robotic control systems.

Electricians read blueprints, which are technical diagrams of electrical systems that show the location of circuits, outlets, and other equipment. They use different types of hand and power tools, such as pipe benders, to run and protect wiring. Other commonly used hand and power tools include screwdrivers, wire strippers, drills, and saws. While troubleshooting, electricians also may use ammeters, voltmeters, and multimeters to find problems and ensure that components are working properly.

Many electricians work independently, but sometimes they collaborate with others. For example, experienced electricians may work with building engineers and architects to help design electrical systems in new construction. Some electricians also may consult with other construction specialists, such as elevator installers and heating and air conditioning workers, to help install or maintain electrical or power systems. At larger companies, electricians are more likely to work as part of a crew; they may direct helpers and apprentices to complete jobs.

The following are examples of occupational specialties:

Inside electricians maintain and repair large motors, equipment, and control systems in businesses and factories. They use their knowledge of electrical systems to help these facilities run safely and efficiently. Some also install the wiring for businesses and factories that are being built. To minimize equipment failure, inside electricians often perform scheduled maintenance.   

Residential electricians install wiring and troubleshoot electrical problems in peoples' homes. Those who work in new-home construction install outlets and provide access to power where needed. Those who work in maintenance and remodeling repair and replace faulty equipment. For example, if a circuit breaker is tripped, electricians determine the reason and fix it.

Carpenters construct and repair building frameworks and structures--such as stairways, doorframes, partitions, and rafters--made from wood and other materials. They also may install kitchen cabinets, siding, and drywall.

Carpenters typically do the following:

• Follow blueprints and building plans to meet the needs of clients
• Install structures and fixtures, such as windows and molding
• Measure, cut, or shape wood, plastic, fiberglass, drywall, and other materials
• Construct building frameworks, including wall studs, floor joists, and doorframes
• Help put up, level, and install building framework with the aid of large pulleys and cranes
• Inspect and replace damaged framework or other structures and fixtures
• Instruct and direct laborers and other construction trade helpers

Carpenters are one of the most versatile construction occupations, with workers usually doing a variety of tasks. For example, some carpenters insulate office buildings; others install drywall or kitchen cabinets in homes. Those who help construct large buildings or bridges often make the wooden concrete forms for cement footings or pillars. Some carpenters build braces and scaffolding for buildings.

Carpenters use many different hand and power tools to cut and shape wood, plastic, fiberglass, or drywall. They commonly use handtools, including squares, levels, and chisels, as well as many power tools, such as sanders, circular saws, and nail guns. Carpenters put materials together with nails, screws, staples, and adhesives, and do a final check of their work to ensure accuracy. They use a tape measure on every project because proper measuring increases productivity, reduces waste, and ensures that the pieces being cut are the proper size.

The following are types of carpenters:

Residential carpenters typically specialize in new-home, townhome, and condominium building and remodeling. As part of a single job, they might build and set forms for footings, walls and slabs, and frame and finish exterior walls, roofs, and decks. They frame interior walls, build stairs, and install drywall, crown molding, doors, and kitchen cabinets. Highly-skilled carpenters may also tile floors and lay wood floors and carpet. Fully-trained construction carpenters are easily able to switch from new-home building to remodeling.

Commercial carpenters typically remodel and help build commercial office buildings, hospitals, hotels, schools, and shopping malls. Some specialize in working with light gauge and load-bearing steel framing for interior partitions, exterior framing, and curtain wall construction. Others specialize in working with concrete forming systems and finishing interior and exterior walls, partitions, and ceilings. Highly skilled carpenters can usually do many of the same tasks as residential carpenters.

Industrial carpenters typically work in civil and industrial settings where they put up scaffolding and build and set forms for pouring concrete. Some industrial carpenters build tunnel bracing or partitions in underground passageways and mines to control the circulation of air to worksites. Others build concrete forms for tunnels, bridges, dams, power plants, or sewer construction projects.

Construction equipment operators drive, maneuver, or control the heavy machinery used to construct roads, bridges, buildings, and other structures.

Construction equipment operators typically do the following:

• Check to make sure that equipment functions properly
• Clean, maintain, and make basic repairs to equipment
• Report malfunctions to supervisors
• Move levers, push pedals, or turn valves to activate power equipment
• Drive and maneuver equipment
• Coordinate machine actions with crew members in response to hand or audio signals
• Ensure that safety standards are met

Construction equipment operators use machinery to move construction materials, earth, and other heavy materials at construction sites and mines. They operate equipment that clears and grades land to prepare it for construction of roads, bridges, and buildings, as well as airport runways, power generation facilities, dams, levees, and other structures.

The following are types of construction equipment operators:

Operating engineers and other construction equipment operators work with one or several types of power construction equipment. They may operate excavation and loading machines equipped with scoops, shovels, or buckets that dig sand, gravel, earth, or similar materials. In addition to operating the familiar bulldozer, they operate trench excavators, road graders, and similar equipment. Sometimes, they may drive and control industrial trucks or tractors equipped with forklifts or booms for lifting materials. They also may operate and maintain air compressors, pumps, and other power equipment at construction sites.

Paving and surfacing equipment operators control the machines that spread and level asphalt or spread and smooth concrete for roadways or other structures. Paving and surfacing equipment operators may specialize further:

• Asphalt spreader operators turn valves to regulate the temperature of asphalt and the flow of asphalt onto the roadbed. They must ensure that the machine distributes the paving material evenly, and they also must ensure that there is a constant flow of asphalt into the hopper.
• Concrete paving machine operators control levers and turn handwheels to move attachments that spread, vibrate, and level wet concrete. They must watch the surface of the concrete carefully to identify low spots into which workers must add concrete.
• Tamping equipment operators use machines that compact earth and other fill materials for roadbeds or other construction sites. They also may operate machines with interchangeable hammers to cut or break up old pavement and drive guardrail posts into the ground.

Piledriver operators use large machines mounted on skids, barges, or cranes to hammer piles into the ground. Piles are long, heavy beams of wood or steel driven into the ground to support retaining walls, bridges, piers, or building foundations. Some piledriver operators work on offshore oil rigs.

Some workers operate cranes to move construction materials. For more information on these workers, see the profile on material moving machine operators.