D C Mechanical

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.

Boilermakers assemble, install, and repair boilers, closed vats, and other large vessels or containers that hold liquids and gases.

Boilermakers typically do the following:

• Use blueprints to determine locations, positions, or dimensions of parts
• Install small premade boilers into buildings and manufacturing facilities
• Lay out prefabricated parts of larger boilers before assembling them
• Assemble boiler tanks, often using robotic or automatic welders
• Test and inspect boiler systems for leaks or defects
• Clean vats using scrapers, wire brushes, and cleaning solvents
• Replace or repair broken valves, pipes, or joints, using hand and power tools, gas torches, and welding equipment

Boilers, tanks, and vats are used in many buildings, factories, and ships. Boilers heat water or other fluids under extreme pressure to generate electric power and to provide heat. Large tanks and vats are used to store and process chemicals, oil, beer, and hundreds of other products.

Boilers are made out of steel, iron, copper, or stainless steel. Manufacturers are increasingly automating the production of boilers to improve the quality of these vessels. However, boilermakers still use many tools in making or repairing boilers. For example, they use hand and power tools or flame cutting torches to cut pieces for a boiler. To bend the pieces into shape and accurately line them up, boilermakers use plumb bobs, levels, wedges, and turnbuckles.

If the plate sections are very large, large cranes lift the parts into place. Once they have the parts lined up, they use metalworking machinery and other tools to remove irregular edges so the parts fit together properly. They join the parts by bolting, welding, or riveting them together.

In addition to installing and maintaining boilers and other vessels, boilermakers help erect and repair air pollution equipment, blast furnaces, water treatment plants, storage and process tanks, and smokestacks. Boilermakers also install refractory brick and other heat-resistant materials in fireboxes or pressure vessels. Some install and maintain the huge pipes used in dams to send water to and from hydroelectric power generation turbines.

Because boilers last a long time--sometimes 50 years or more--boilermakers must regularly maintain them and upgrade parts. They frequently inspect fittings, feed pumps, safety and check valves, water and pressure gauges, and boiler controls.

Plumbers, pipefitters, and steamfitters install and repair pipes that carry water, steam, air, or other liquids or gases to and in businesses, homes, and factories.

Plumbers, pipefitters, and steamfitters typically do the following:

• Install pipes and fixtures
• Study blueprints and follow state and local building codes
• Determine the amount of material and type of equipment needed
• Inspect and test installed pipe systems and pipelines
• Troubleshoot and repair systems that are not working
• Replace worn parts

Although plumbers, pipefitters, and steamfitters are three distinct specialties, their duties are often similar. For example, they all install pipes and fittings that carry water, steam, air, or other liquids or gases. They connect pipes, determine the necessary materials for a job, and perform pressure tests to ensure a pipe system is airtight and watertight.

Plumbers, pipefitters, and steamfitters install, maintain, and repair many different types of pipe systems. Some of these systems carry water, dispose of waste, supply gas to ovens, or heat and cool buildings. Other systems, such as those in power plants, carry the steam that powers huge turbines. Pipes also are used in manufacturing plants to move acids, gases, and waste byproducts through the production process.

Master plumbers on construction jobs may be involved with developing blueprints that show where all the pipes and fixtures will go. Their input helps ensure that a structure's plumbing meets building codes, stays within budget, and works well with the location of other features, such as electric wires.

Plumbers and fitters may use many different materials and construction techniques, depending on the type of project. Residential water systems, for example, use copper, steel, and plastic pipe that one or two plumbers can install. Power-plant water systems, by contrast, are made of large steel pipes that usually take a crew of pipefitters to install. Some workers install stainless steel pipes on dairy farms and in factories, mainly to prevent contamination.

Plumbers and fitters sometimes cut holes in walls, ceilings, and floors. With some pipe systems, workers may hang steel supports from ceiling joists to hold the pipe in place. Because pipes are seldom manufactured to the exact size or length, plumbers and fitters measure and then cut and bend lengths of pipe as needed. Their tools include saws, pipe cutters, and pipe-bending machines.

They then connect the pipes, using methods that vary by type of pipe. For example, copper pipe is joined with solder, but steel pipe is often screwed together.

In addition to installation and repair work, journey- and master-level plumbers, pipefitters, and steamfitters often direct apprentices and helpers.

Following are examples of occupational specialties:

Plumbers install and repair water, drainage, and gas pipes in homes, businesses, and factories. They install and repair large water lines, such as those that supply water to buildings, and smaller ones, including ones that supply water to refrigerators. Plumbers also install plumbing fixtures--bathtubs, showers, sinks, and toilets--and appliances such as dishwashers, garbage disposals, and water heaters. They also fix plumbing problems. For example, when a pipe is clogged or leaking, plumbers remove the clog or replace the pipe. Some plumbers maintain septic systems, the large, underground holding tanks that collect waste from houses not connected to a city or county's sewer system.

Pipefitters install and maintain pipes that carry chemicals, acids, and gases. These pipes are mostly in manufacturing, commercial, and industrial settings. They often install and repair pipe systems in power plants, as well as heating and cooling systems in large office buildings. Some pipefitters specialize:

• Gasfitters install pipes that provide clean oxygen to patients in hospitals.
• Sprinklerfitters install and repair fire sprinkler systems in businesses, factories, and residential buildings.
• Steamfitters installpipe systems that move steam under high pressure. Most steamfitters work at campus and natural gas power plants where heat and electricity is generated, but others work in factories that use high-temperature steam pipes.

Heating, air conditioning, and refrigeration mechanics and installers--often referred to as HVACR technicians--work on heating, ventilation, cooling, and refrigeration systems that control the air quality in many types of buildings.

Heating, air conditioning, and refrigeration mechanics and installers typically do the following:

• Travel to worksites
• Follow blueprints or other design specifications to install or repair HVACR systems
• Connect systems to fuel and water supply lines, air ducts, and other components
• Install electrical wiring and controls and test for proper operation
• Inspect and maintain customers' HVACR systems
• Test individual components to determine necessary repairs
• Repair or replace worn or defective parts

Heating and air conditioning systems control the temperature, humidity, and overall air quality in homes, businesses, and other buildings. By providing a climate controlled environment, refrigeration systems make it possible to store and transport food, medicine, and other perishable items.

Although trained to do all three, HVACR technicians sometimes work strictly with heating, air conditioning, or refrigeration systems. They also may specialize in certain types of HVACR equipment, such as water-based heating systems, solar panels, or commercial refrigeration.

Depending on the task, HVACR technicians use many different tools. For example, they often use screwdrivers, wrenches, pipe cutters and other basic handtools when installing systems. To test or install complex system components, technicians may use more sophisticated tools, such as carbon monoxide testers, voltmeters, combustion analyzers, and acetylene torches.

When working on air conditioning and refrigeration systems, technicians must follow government regulations regarding the conservation, recovery, and recycling of refrigerants. This often entails proper handling and disposal of fluids.  

Some HVACR technicians sell service contracts to their clients, providing regular maintenance of heating and cooling systems.

Other craft workers sometimes help install or repair cooling and heating systems. For example, on a large air conditioning installation job, especially one in which workers are covered by union contracts, ductwork might be done by sheet metal workers and duct installers, or electrical work by electricians. In addition, home appliance repairers usually service window air conditioners and household refrigerators. For more information on these occupations, see the profiles on sheet metal workers, electricians, or home appliance repairers.

Construction laborers and helpers do many basic tasks that require physical labor on construction sites.

Construction laborers and helpers typically do the following:

• Clean and prepare construction sites by removing debris and possible hazards
• Load or unload building materials to be used in construction
• Build or take apart bracing, barricades, forms (molds that determine the shape of concrete), scaffolding, and temporary structures
• Dig trenches, backfill holes, or compact earth to prepare for construction
• Operate or tend equipment and machines used in construction, such as concrete mixers
• Help other craftworkers with their duties
• Follow construction plans and instructions from the people they are working for

Construction laborers and helpers work on almost all construction sites, doing a wide range of tasks from the very easy to the extremely difficult and hazardous. Although many of the tasks they do require some training and experience, most jobs usually require little skill and can be learned quickly. 

The following are occupational specialties:

Construction laborers do a variety of construction-related activities during all phases of construction. Although most laborers are generalists--such as those who install barricades, cones, and markers to control traffic patterns--many others specialize. For example, those who operate the machines and equipment that lay concrete or asphalt on roads are more likely to specialize in those areas.

Most construction laborers work in the following areas:

• Building homes and businesses
• Tearing down buildings
• Removing hazardous materials
• Building highways and roads
• Digging tunnels and mine shafts

Construction laborers use a variety of tools and equipment. Some tools are simple, such as brooms and shovels; other equipment is more sophisticated, such as pavement breakers, jackhammers, earth tampers, and surveying equipment.

With special training, laborers may help transport and use explosives or run hydraulic boring machines to dig out tunnels. They may learn to use laser beam equipment to place pipes and use computers to control robotic pipe cutters. They may become certified to remove asbestos, lead, or chemicals.

Helpers assist construction craftworkers, such as electricians and carpenters, with a variety of basic tasks. They may carry tools and materials or help set up equipment. For example, many helpers work with cement masons to move and set forms. Many other helpers assist with taking apart equipment, cleaning up sites, and disposing of waste, as well as helping with any other needs of craftworkers.

Many construction trades have helpers who assist craftworkers. The following are examples of trades that have associated helpers:

• Brickmasons, blockmasons, stonemasons, and tile and marble setters
• Carpenters
• Electricians
• Painters, paperhangers, plasterers, and stucco masons
• Pipelayers, plumbers, pipefitters, and steamfitters
• Roofers