Roofers repair and install the roofs of buildings using a variety of materials, including shingles, asphalt, and metal.
Roofers typically do the following:
Properly installed roofs keep water from leaking into buildings and damaging the interior, equipment, or furnishings.
There are two basic types of roofs, low-slope and steep-slope:
A small but increasing number of buildings now have “green” roofs that incorporate landscape roofing systems. A landscape roofing system typically begins with a single or multiple waterproof layers. After that layer is proven to be leak free, roofers put a root barrier over it, and, finally, layers of soil, in which vegetation is planted. Roofers must ensure that the roof is watertight and can endure the weight and water needs of the plants.
Construction and building inspectors ensure that new construction, changes, or repairs comply with local and national building codes and ordinances, zoning regulations, and contract specifications.
Construction and building inspectors typically do the following:
Construction and building inspectors examine buildings, highways and streets, sewer and water systems, dams, bridges, and other structures. They also inspect electrical; heating, ventilation, air-conditioning, and refrigeration (HVACR); and plumbing systems. Although no two inspections are alike, inspectors do an initial check during the first phase of construction and follow-up inspections throughout the construction project. When the project is finished, they do a final, comprehensive inspection.
The following are types of construction and building inspectors:
Building inspectors check the structural quality and general safety of buildings. Some specialize in structural steel or reinforced-concrete structures, for example.
Electrical inspectors examine the installed electrical systems to ensure they function properly and comply with electrical codes and standards. The inspectors visit worksites to inspect new and existing sound and security systems, wiring, lighting, motors, and generating equipment. They also inspect the installed electrical wiring for HVACR systems and appliances.
Elevator inspectors examine lifting and conveying devices, such as elevators, escalators, moving sidewalks, lifts and hoists, inclined railways, ski lifts, and amusement rides.
Home inspectors typically inspect newly built or previously owned homes, condominiums, townhomes, and other dwellings. Prospective home buyers often hire home inspectors to check and report on a home's structure and overall condition. Sometimes, homeowners hire a home inspector to evaluate their home's condition before placing it on the market.
In addition to examining structural quality, home inspectors examine all home systems and features, including roofing, exterior walls, attached garage or carport, foundation, interior, plumbing, electrical, and HVACR systems. They look for and report violations of building codes, but they do not have the power to enforce compliance with the codes.
Mechanical inspectors examine the installation of HVACR systems and equipment to ensure that they are installed and function properly. They also may inspect commercial kitchen equipment, gas-fired appliances, and boilers.
Plan examiners determine whether the plans for a building or other structure comply with building codes. They also determine whether the structure is suited to the engineering and environmental demands of the building site.
Plumbing inspectors examine the installation of potable water, waste, and vent piping systems to ensure the safety and health of the drinking water system, piping for industrial uses, and the sanitary disposal of waste.
Public works inspectors ensure that federal, state, and local government water and sewer systems, highways, streets, bridges, and dam construction conform to detailed contract specifications. Workers inspect excavation and fill operations, the placement of forms for concrete, concrete mixing and pouring, asphalt paving, and grading operations. Public works inspectors may specialize in highways, structural steel, reinforced concrete, or ditches. Others specialize in dredging operations required for bridges and dams or for harbors.
Specification inspectors ensure that work is performed according to design specifications. Specification inspectors represent the owner's interests, not those of the general public. Insurance companies and financial institutions also may use their services.
A primary concern of building inspectors is fire prevention safety. For more information, see the profile on fire inspectors and investigators.
Metal and plastic machine workers set up and operate machines that cut, shape, and form metal and plastic materials or pieces.
Metal and plastic machine workers typically do the following:
Consumer products are made with many metal and plastic parts. These parts are produced by machines that are operated by metal and plastic machine workers. In general, these workers are separated into two groups: those who set up machines for operation and those who operate machines during production.
Although many workers both set up and operate the machines, some specialize in one of the following job types:
Machine setters, or setup workers, prepare the machines before production, perform test runs, and, if necessary, adjust and make minor repairs to the machinery before and during operation.
If, for example, the cutting tool inside a machine becomes dull after extended use, it is common for a setter to remove the tool, use a grinder or file to sharpen it, and place it back into the machine.
New tools are produced by tool and die makers. For more information, see the profile on machinists and tool and die makers.
After installing the tools into a machine, setup workers often produce the initial batch of goods, inspect the products, and turn the machine over to an operator.
Machine operators and tenders monitor the machinery during operation.
After a setter prepares a machine for production, an operator observes the machine and the products it produces. Operators may have to load the machine with materials for production or adjust the machine's speeds during production. They must periodically inspect the parts a machine produces. If they detect a minor problem, operators may fix it themselves. If the repair is more serious, they may have an industrial machinery mechanic fix it. For more information, see the profile on industrial machinery mechanics and maintenance workers.
Setters, operators, and tenders usually are identified by the type of machine they work with. Job duties usually vary with the size of the manufacturer and the type of machine being operated. Although some workers specialize in one or two types of machinery, many are trained to set up or operate a variety of machines. Increasing automation allows machine setters to operate multiple machines at the same time.
In addition, newer production techniques, such as team-oriented “lean” manufacturing, require machine operators to rotate between different machines. Rotating assignments results in more varied work but also requires workers to have a wider range of skills.
The following are types of metal and plastic machine workers:
Computer-controlled machine tool operators, metal and plastic operate computer-controlled machines or robots to perform functions on metal or plastic workpieces.
Computer numerically controlled machine tool programmers, metal and plastic develop programs to control the machining or processing of metal or plastic parts by automatic machine tools, equipment, or systems.
Extruding and drawing machine setters, operators, and tenders, metal and plastic set up or operate machines to extrude (pull out) or draw thermoplastic or metal materials into tubes, rods, hoses, wire, bars, or structural shapes.
Forging machine setters, operators, and tenders, metal and plastic set up or operate machines that taper, shape, or form metal or plastic parts.
Rolling machine setters, operators, and tenders, metal and plastic set up or operate machines to roll steel or plastic or to flatten, temper, or reduce the thickness of material.
Cutting, punching, and press machine setters, operators, and tenders, metal and plastic set up or operate machines to saw, cut, shear, notch, bend, or straighten metal or plastic material.
Drilling and boring machine tool setters, operators, and tenders, metal and plastic set up or operate drilling machines to drill, bore, mill, or countersink metal or plastic workpieces.
Grinding, lapping, polishing, and buffing machine tool setters, operators, and tenders, metal and plastic set up or operate grinding and related tools that remove excess material from surfaces, sharpen edges or corners, or buff or polish metal or plastic workpieces.
Lathe and turning machine tool setters, operators, and tenders, metal and plastic set up or operate lathe and turning machines to turn, bore, thread, form, or face metal or plastic materials, such as wire or rod.
Milling and planing machine setters, operators, and tenders, metal and plastic set up or operate milling or planing machines to shape, groove, or profile metal or plastic workpieces.
Metal-refining furnace operators and tenders operate or tend furnaces, such as gas, oil, coal, electric-arc or electric induction, open-hearth or oxygen furnaces to melt and refine metal before casting or to produce specified types of steel.
Pourers and casters, metal operate hand-controlled mechanisms to pour and regulate the flow of molten metal into molds to produce castings or ingots.
Model makers, metal and plastic set up and operate machines, such as milling and engraving machines and jig borers, to make working models of metal or plastic objects.
Patternmakers, metal and plastic lay out, machine, fit, and assemble castings and parts to metal or plastic foundry patterns, coreboxes, or match plates.
Foundry mold and coremakers make or form wax or sand cores or molds used in the production of metal castings in foundries.
Molding, coremaking, and casting machine setters, operators, and tenders, metal and plastic set up or operate metal or plastic molding, casting, or coremaking machines to mold or cast metal or thermoplastic parts or products.
Multiple machine tool setters, operators, and tenders, metal and plastic set up or operate more than one type of cutting or forming machine tool or robot.
Welding, soldering, and brazing machine setters, operators, and tenders (including workers who operate laser cutters or laser-beam machines) set up or operate welding, soldering, or brazing machines or robots that weld, braze, solder, or heat treat metal products, components, or assemblies.
Heat treating equipment setters, operators, and tenders, metal and plastic set up or operate heating equipment, such as heat treating furnaces, flame-hardening machines, induction machines, soaking pits, or vacuum equipment, to temper, harden, anneal, or heat treat metal or plastic objects.
Plating and coating machine setters, operators, and tenders, metal and plastic set up or operate plating or coating machines to coat metal or plastic products with zinc, copper, nickel, or some other metal to protect or decorate surfaces (includes electrolytic processes).
Sheet metal workers fabricate or install products that are made from thin metal sheets, such as ducts used for heating and air-conditioning.
Sheet metal workers typically do the following:
Sheet metal workers make, install, and maintain thin sheet metal products. Although sheet metal is used to make many products, such as rain gutters, outdoor signs, and siding, it is most commonly used to make ducts for heating and air-conditioning.
Sheet metal workers study plans and specifications to determine the kind and quantity of materials they will need. Using computer-controlled saws, lasers, shears, and presses, they measure, cut, bend, and fasten pieces of sheet metal.
In shops without computerized equipment, sheet metal workers make the required calculations and use tapes and rulers to lay out the work. Then, they cut or stamp the parts with machine tools.
In manufacturing plants, sheet metal workers program and operate computerized metalworking equipment. For example, they may make sheet metal parts for aircraft or industrial equipment. Sheet metal workers in those jobs may be responsible for programming the computer control systems of the equipment they operate.
Before assembling pieces, sheet metal workers check each part for accuracy. If necessary, they use hand, rotary, or squaring shears and hacksaws to finish pieces.
After inspecting the metal pieces, workers fasten seams and joints with welds, bolts, rivets, solder, or other connecting devices. Then they take the parts constructed in the shop and assemble the pieces further as they install them.
Most fabrication work is done in shops with some final assembly done on the job. Some jobs are done completely at the jobsite. When installing a metal roof, for example, sheet metal workers usually measure and cut the roofing panels onsite.
In addition to installing sheet metal, some workers install fiberglass and plastic board.
In some shops and factories, sheet metal workers care for and maintain the equipment they use.
Sheet metal workers do both construction-related work and the mass production of sheet metal products in manufacturing. Sheet metal workers are often separated into four specialties: fabrication, installation, maintenance, and testing and balancing. The following describes these types of sheet metal workers:
Fabrication sheet metal workers, sometimes called precision sheet metal workers, make ducts, gutters, and other metal products. Most work in shops and factories, operating tools and equipment. Although some of the fabrication techniques used in large-scale manufacturing are similar to those used in smaller shops, the work may be highly automated and repetitive. Many fabrication shops have automated machinery, and workers use computer-aided drafting (CAD) and building information modeling (BIM) systems to make products.
Installation sheet metal workers install heating, ventilation, and air-conditioning (HVAC) ducts. They also install other sheet metal products, such as metal roofs, siding, or gutters. They work on new construction and on renovation projects.
Maintenance sheet metal workers repair and clean ventilation systems so the systems use less energy. Workers remove dust and moisture and fix leaks or breaks in the sheet metal that makes up the ductwork.
Testing and balancing sheet metal specialists ensure that HVAC systems heat and cool rooms properly. They ensure that hot and cold air is transferred through sheet metal ducts efficiently. For more information on workers who install or repair HVAC systems, see the profile on heating, air conditioning, and refrigeration mechanics and installers.
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:
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.