37 Planning and counsel in building and construction; building demolition; sealing of pavement and buildings; roofing installation and repair; installation of building insulation; electrical contracting; electrical repair and installation of machines used in agriculture and of machines used for the handling of agrochemical substances; building framing; cleaning of facades; tile-laying work; floor-laying work; dehumidification of buildings; bridge construction; construction of permanent ways for railroads; plastering and tiling; building repair and construction maintenance; road and highway construction; tunnel construction; hydraulic construction; installation, assembly and repair of lighting installations, lightning protection systems, radio and telecommunications equipment, heating, ventilating and air-conditioning systems, industrial plants, refrigeration plants, mechanical equipment, sanitary installations and equipment; plumbing work and gas and water heater and tanks installation; painting contracting; house painting; furniture varnishing and wallpapering; laying parquet wood flooring; laying of piping; cleaning of buildings, chimneys, conduits, motor vehicles, textiles; repair and maintenance of coverings, heating, air conditioning, cooling and ventilating systems, motor vehicles, aircraft, mechanical equipment and devices for medical and orthopedic use, photographic projection and movie equipment, upholstery, ships, shoes, timepieces, heating systems; shipbuilding; blasting; stucco work, plastering and plaster work; laying of land and ocean cables; leasing of machinery, tools and equipment for construction; non-agricultural destruction of pests, vermin and weeds; washing of laundry, carpentry contractor services; construction of wooden roof trusses; construction of wooden buildings; construction of wooden stairs