Installs and repairs electrical wiring and equipment; May clean, maintain and make repairs to boilers, pumps, heaters, piping, valves, traps, compressor motors and generators; Builds and/or installs cabinets, shelves, doors, paneling, flooring, windows and locks; Installs and repairs plumbing fixtures such as sinks, toilets and showers; Operate and/or perform minor repairs to motor vehicles, and other motorized equipment; Repairs windows, doors, floors, walls, furniture, roofs, projectors, screens and sprinklers; Performs masonry duties such as mixing plaster and concrete, laying brick or blocks, preparing forms and pouring concretes; Prepares surfaces and paints exteriors and interiors of buildings and structures; Performs general grounds maintenance activities; May supervise the work of laborers or other subordinates. Thorough knowledge of the practices, processes, materials and tools of the principal trade in which the experience has been gained; good knowledge of modern buildings and grounds maintenance and repair practices; good knowledge of the operation and maintenance of heating and ventilating equipment; ability to plan and supervise the work of others; ability to understand and carry out oral and written directions; mechanical aptitude; manual dexterity; physical condition commensurate with the demands of the position.