6
Non-electric cables and wires of common metal; safes; ores; inks, anvils, bells; cassettes; rails and other materials of metal for railway tracks; chains (except transmission chains for vehicles); cassettes; ducts of metal for ventilation installations
11
Apparatus for ventilating and smoke-extraction purposes; installation of ventilation and smoke-extraction apparatus; air-purifying apparatus and machines; air filters; air filtering installations
19
Building stone; natural and artificial stone, cement, lime, mortar, plaster and gravel; concrete; pipes of earthenware or of cement; products for the construction of roads; asphalts; pitch and bitumen; transformable homes, except prefabricated, mobile and/or moveable buildings; monuments of stone; chimneys; drain pipes, not of metal; ducts, not of metal, for ventilation installations
37
Construction of buildings namely construction of building structures and frames made entirely of metal and glass except gates or component parts of gates; painting, plastering, plumbing, roofing; public works, rural works; rental of tools or construction equipment, rental of bulldozers and tree uprooting equipment
42
Engineering, professional consultancy and construction drafting, non-business; architectural consultation; engineering drawing; technical research; engineering work (except for construction); prospecting; material testing; laboratories; all the aforesaid services relating to the study and realisation of atrium roofs and buildings whose structure and frame are made of metal and glass panels