Insulators work with different kinds of insulation material to prevent or reduce the passage of heat, cold, vapour, moisture, sound or fire. They read and interpret drawings and specifications to determine insulation requirements, select the amount and type of insulation to be installed and measure and cut insulating material to the required dimensions. They then apply, install, repair and maintain insulation material. Insulated surfaces may be finished with materials such as plastics, aluminum, galvanized steel and coated steel, stainless steel, canvas, mastic, laminate or concrete. Some insulators may also lay out and fabricate parts on-site or remove or seal off old insulation.

Types of insulation materials that may be used include calcium silicate, ceramic fibre, elastomeric insulation, mineral fibre, fibreglass, urethane, polystyrene and cellular glass. They may be used for systems such as plumbing, air-handling, heating, cooling and refrigeration, for piping equipment and pressure vessels, as well as for walls, floors and ceilings of buildings, industrial complexes and ships.

Removing old insulation material such as asbestos, ceramic fibres, lead and mould is also part of the trade. Special training and licenses may be required to deal with these types of materials. Spraying insulation materials is another specialized part of the trade.

Insulators are employed by construction companies, insulation contractors and industrial plants, or may also be self-employed. They work on residential, industrial, commercial and institutional projects. Their work schedules depend on the type of work they are doing, ranging from 40-hour weeks with possible overtime in order to meet deadlines, to shift work in plants or irregular work hours. Schedules may depend on the availability of contracts or inconvenience or health risks to adjacent workers or the public.

Insulators work with a number of hand tools and power tools. Insulators use equipment such as respirators, coveralls and safety glasses to protect themselves from the hazards of materials. Also, insulators frequently require scaffolds, aerial lifts and ladders to help them accomplish their tasks. They can work indoors or outdoors, often in extreme temperatures. Depending on the location of work, they may be required to travel.

The ability to be focused and responsible is a vital part of insulators' work and safety. The work often requires spending most of the day on their feet, bending, kneeling, working at heights, climbing (scaffolds, ladders) and lifting. Insulators must be able to use their body to brace large items and guide objects or materials into place. This requires them to have a good combination of motor co-ordination and manual and finger dexterity.

This analysis recognizes similarities or overlaps with the work of roofers, sheet metal workers, painters and carpenters.

With experience, insulators act as mentors and trainers to apprentices in the trade. They could also move into positions such as maintenance, instructor, contractor, foreperson, superintendent or estimator.